TOHOKU UNIVERSITY Researchers

Ayumi Hirano

Section

Research Institute of Electrical Communication

Job title

Professor

Degree

博士（理学）（東京大学）
修士（理学）（東京大学）

researchmap

https://researchmap.jp/ayumihiranoiwata

Research History 7

2016/10 - Present

東北大学材料科学高等研究所
2016/10 - Present

東北大学電気通信研究所
2008/04 -

東北大学大学院医工学研究科
2006/10 -

東北大学電気通信研究所
2003/09 -

National institute for Medical Research, UK
2000/04 -

日本大学文理学部
1998/11 -

日本学術振興会特別研究員（日本大学文理学部）

Show all Show first 5

Education 2

The University of Tokyo　Graduate School, Division of Chemistry

- 1998/03
The University of Tokyo　Faculty of Science

- 1993/03

Committee Memberships 19

応用物理学会　講演会担当理事

2023/03 - Present
日本表面真空学会　理事

2020/04 - Present
表面科学会ソフトナノテクノロジー部会　部会長

2017/05 - Present
JST　さきがけ、ＣＲＥＳＴ領域アドバイザー

2013/05 - Present
日本分析化学会東北支部　在仙幹事

2007/04 - Present
日本分析化学会東北支部　在仙幹事

2007/04 - Present
応用物理学会　Ｍ＆ＢＥ分科会常任幹事

2017/03 - 2019/03
表面科学会ソフトナノテクノロジー部会　副部会長

2013/05 - 2017/04
ISSS7(The 7th International Symposium on Surface Science)　プログラム委員副委員長

2012/12 - 2014/11
ISSS7(The 7th International Symposium on Surface Science)　プログラム委員副委員長

2012/12 - 2014/11
日本分析化学会　ぶんせき誌編集委員

2012/03 - 2013/03
応用物理学会有機分子・バイオエレクトロニクス分科会　幹事

2011/03 - 2013/03
応用物理学会有機分子・バイオエレクトロニクス分科会　幹事

2011/03 - 2013/03
日本分析化学会　東北支部会計幹事

2010/03 - 2012/03
日本分析化学会　東北支部会計幹事

2010/03 - 2012/03
日本分析化学会　第５９年会実行委員会計幹事

2010/03 - 2010/12
日本分析化学会　第５９年会実行委員会計幹事

2010/03 - 2010/12
日本分析化学会関東支部　幹事

2002/04 -
日本分析化学会関東支部　幹事

2002/04 -

Show all ︎Show first 5

Professional Memberships 5

American Chemical Society
日本表面科学会
応用物理学会
日本化学会
日本分析化学会

Research Interests 3

神経情報伝達
ナノ構造
人工細胞膜

Research Areas 2

Nanotechnology/Materials / Analytical chemistry /
Natural sciences / Bio-, chemical, and soft-matter physics /

Awards 6

日本表面真空学会フェロー

2020/11
応用物理学会フェロー

2019/09
平成２７年度石田實記念財団研究奨励賞

2015/11/27　石田實記念財団
平成２７年度RIEC Award 東北大学研究者賞

2015/11/25　東北大学電気通信研究所
2014年度東北分析化学賞

2015/03　日本分析化学会東北支部
2005年度日本分析化学会奨励賞

2005/09　日本分析化学会

Show all ︎Show 5

Papers 150

Enhanced responses to inflammatory cytokine interleukin-6 in micropatterned networks of cultured cortical neurons Invited

Mamoru Sakaibara, Hideaki Yamamoto, Hakuba Murota, Nobuaki Monma, Shigeo Sato, Ayumi Hirano-Iwata

Biochemical and Biophysical Research Communications　2024/02

DOI： 10.1016/j.bbrc.2023.149379 　
Model-free idealization: Adaptive integrated approach for idealization of ion-channel currents Peer-reviewed

Madoka Sato, Masanori Hariyama, Maki Komiya, Kae Suzuki, Yuzuru Tozawa, Hideaki Yamamoto, Ayumi Hirano-Iwata

Biophysical Journal　122　(19)　3959-3975　2023/10
Publisher: Elsevier BV
DOI： 10.1016/j.bpj.2023.08.019 　

ISSN：0006-3495
Modular architecture facilitates noise-driven control of synchrony in neuronal networks Peer-reviewed

Hideaki Yamamoto, F. Paul Spitzner, Taiki Takemuro, Victor Buendía, Hakuba Murota, Carla Morante, Tomohiro Konno, Shigeo Sato, Ayumi Hirano-Iwata, Anna Levina, Viola Priesemann, Miguel A. Muñoz, Johannes Zierenberg, Jordi Soriano

Science Advances　9　(34)　2023/08/25
Publisher: American Association for the Advancement of Science (AAAS)
DOI： 10.1126/sciadv.ade1755 　

eISSN：2375-2548

More details Close

High-level information processing in the mammalian cortex requires both segregated processing in specialized circuits and integration across multiple circuits. One possible way to implement these seemingly opposing demands is by flexibly switching between states with different levels of synchrony. However, the mechanisms behind the control of complex synchronization patterns in neuronal networks remain elusive. Here, we use precision neuroengineering to manipulate and stimulate networks of cortical neurons in vitro, in combination with an in silico model of spiking neurons and a mesoscopic model of stochastically coupled modules to show that (i) a modular architecture enhances the sensitivity of the network to noise delivered as external asynchronous stimulation and that (ii) the persistent depletion of synaptic resources in stimulated neurons is the underlying mechanism for this effect. Together, our results demonstrate that the inherent dynamical state in structured networks of excitable units is determined by both its modular architecture and the properties of the external inputs.
Biological neurons act as generalization filters in reservoir computing Peer-reviewed

Takuma Sumi, Hideaki Yamamoto, Yuichi Katori, Koki Ito, Satoshi Moriya, Tomohiro Konno, Shigeo Sato, Ayumi Hirano-Iwata

Proceedings of the National Academy of Sciences　120　(25)　2023/06/12
Publisher: Proceedings of the National Academy of Sciences
DOI： 10.1073/pnas.2217008120 　

ISSN：0027-8424

eISSN：1091-6490

More details Close

Reservoir computing is a machine learning paradigm that transforms the transient dynamics of high-dimensional nonlinear systems for processing time-series data. Although the paradigm was initially proposed to model information processing in the mammalian cortex, it remains unclear how the nonrandom network architecture, such as the modular architecture, in the cortex integrates with the biophysics of living neurons to characterize the function of biological neuronal networks (BNNs). Here, we used optogenetics and calcium imaging to record the multicellular responses of cultured BNNs and employed the reservoir computing framework to decode their computational capabilities. Micropatterned substrates were used to embed the modular architecture in the BNNs. We first show that the dynamics of modular BNNs in response to static inputs can be classified with a linear decoder and that the modularity of the BNNs positively correlates with the classification accuracy. We then used a timer task to verify that BNNs possess a short-term memory of several 100 ms and finally show that this property can be exploited for spoken digit classification. Interestingly, BNN-based reservoirs allow categorical learning, wherein a network trained on one dataset can be used to classify separate datasets of the same category. Such classification was not possible when the inputs were directly decoded by a linear decoder, suggesting that BNNs act as a generalization filter to improve reservoir computing performance. Our findings pave the way toward a mechanistic understanding of information representation within BNNs and build future expectations toward the realization of physical reservoir computing systems based on BNNs.
Microfluidic cell engineering on high-density microelectrode arrays for assessing structure-function relationships in living neuronal networks Peer-reviewed

Yuya Sato, Hideaki Yamamoto, Hideyuki Kato, Takashi Tanii, Shigeo Sato, Ayumi Hirano-Iwata

Frontiers in Neuroscience　16　2023/01/09
Publisher: Frontiers Media SA
DOI： 10.3389/fnins.2022.943310 　

eISSN：1662-453X

More details Close

Neuronal networks in dissociated culture combined with cell engineering technology offer a pivotal platform to constructively explore the relationship between structure and function in living neuronal networks. Here, we fabricated defined neuronal networks possessing a modular architecture on high-density microelectrode arrays (HD-MEAs), a state-of-the-art electrophysiological tool for recording neural activity with high spatial and temporal resolutions. We first established a surface coating protocol using a cell-permissive hydrogel to stably attach a polydimethylsiloxane microfluidic film on the HD-MEA. We then recorded the spontaneous neural activity of the engineered neuronal network, which revealed an important portrait of the engineered neuronal network–modular architecture enhances functional complexity by reducing the excessive neural correlation between spatially segregated modules. The results of this study highlight the impact of HD-MEA recordings combined with cell engineering technologies as a novel tool in neuroscience to constructively assess the structure-function relationships in neuronal networks.
Filtration-processed biomass nanofiber electrodes for flexible bioelectronics Peer-reviewed

Daiki Ando, Tetsuhiko F. Teshima, Francisco Zurita, Hu Peng, Kota Ogura, Kenji Kondo, Lennart Weiß, Ayumi Hirano-Iwata, Markus Becherer, Joe Alexander, Bernhard Wolfrum

Journal of Nanobiotechnology　20　(1)　2022/11/19
Publisher: Springer Science and Business Media LLC
DOI： 10.1186/s12951-022-01684-3 　

eISSN：1477-3155

More details Close

Abstract An increasing demand for bioelectronics that interface with living systems has driven the development of materials to resolve mismatches between electronic devices and biological tissues. So far, a variety of different polymers have been used as substrates for bioelectronics. Especially, biopolymers have been investigated as next-generation materials for bioelectronics because they possess interesting characteristics such as high biocompatibility, biodegradability, and sustainability. However, their range of applications has been restricted due to the limited compatibility of classical fabrication methods with such biopolymers. Here, we introduce a fabrication process for thin and large-area films of chitosan nanofibers (CSNFs) integrated with conductive materials. To this end, we pattern carbon nanotubes (CNTs), silver nanowires, and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) by a facile filtration process that uses polyimide masks fabricated via laser ablation. This method yields feedlines of conductive material on nanofiber paper and demonstrates compatibility with conjugated and high-aspect-ratio materials. Furthermore, we fabricate a CNT neural interface electrode by taking advantage of this fabrication process and demonstrate peripheral nerve stimulation to the rapid extensor nerve of a live locust. The presented method might pave the way for future bioelectronic devices based on biopolymer nanofibers.
Lateral voltage as a new input for artificial lipid bilayer systems Peer-reviewed

Teng Ma, Madoka Sato, Maki Komiya, Kensaku Kanomata, Takaya Watanabe, Xingyao Feng, Ryusuke Miyata, Daisuke Tadaki, Fumihiko Hirose, Yuzuru Tozawa, Ayumi Hirano-Iwata

Faraday Discussions　233　244-256　2022
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d1fd00045d 　

ISSN：1359-6640

eISSN：1364-5498

More details Close

In this work, we propose lateral voltage as a new input for use in artificial lipid bilayer systems in addition to the commonly used transmembrane voltage. To apply a lateral...
Advances in Artificial Cell Membrane Systems as a Platform for Reconstituting Ion Channels International-journal Peer-reviewed

Maki Komiya, Miki Kato, Daisuke Tadaki, Teng Ma, Hideaki Yamamoto, Ryugo Tero, Yuzuru Tozawa, Michio Niwano, Ayumi Hirano‐Iwata

The Chemical Record　20　(7)　730-742　2020/01/16
Publisher: Wiley
DOI： 10.1002/tcr.201900094 　

ISSN：1527-8999

eISSN：1528-0691
Modulation of Photoinduced Transmembrane Currents in a Fullerene-Doped Freestanding Lipid Bilayer by a Lateral Bias Peer-reviewed

Teng Ma, Xingyao Feng, Takeshi Ohori, Ryusuke Miyata, Daisuke Tadaki, Daichi Yamaura, Takafumi Deguchi, Maki Komiya, Kensaku Kanomata, Fumihiko Hirose, Michio Niwano, Ayumi Hirano-Iwata

ACS Omega　4　18299-18303　2019/10
Impact of modular organization on dynamical richness in cortical networks Peer-reviewed

Hideaki Yamamoto, Satoshi Moriya, Katsuya Ide, Takeshi Hayakawa, Hisanao Akima, Shigeo Sato, Shigeru Kubota, Takashi Tanii, Michio Niwano, Sara Teller, Jordi Soriano, Ayumi Hirano-Iwata

Sci. Adv.　4　eaau4914　2018/11
Mechanically stable solvent-free lipid bilayers in nano- and micro-tapered apertures for reconstitution of cell-free synthesized hERG channels Peer-reviewed

Daisuke Tadaki, Daichi Yamaura, Shun Araki, Miyu Yoshida, Kohei Arata, Takeshi Ohori, Ken-ichi Ishibashi, Miki Kato, Teng Ma, Ryusuke Miyata, Yuzuru Tozawa, Hideaki Yamamoto, Michio Niwano, Ayumi Hirano-Iwata

SCIENTIFIC REPORTS　7　17736　2017/12
Publisher: NATURE PUBLISHING GROUP
DOI： 10.1038/s41598-017-17905-x 　

ISSN：2045-2322

More details Close

The self-assembled bilayer lipid membrane (BLM) is the basic component of the cell membrane. The reconstitution of ion channel proteins in artificially formed BLMs represents a well-defined system for the functional analysis of ion channels and screening the effects of drugs that act on them. However, because BLMs are unstable, this limits the experimental throughput of BLM reconstitution systems. Here we report on the formation of mechanically stable solvent-free BLMs in microfabricated apertures with defined nano- and micro-tapered edge structures. The role of such nano- and micro-tapered structures on the stability of the BLMs was also investigated. Finally, this BLM system was combined with a cell-free synthesized human ether-alpha-go-go-related gene channel, a cardiac potassium channel whose relation to arrhythmic side effects following drug treatment is well recognized. Such stable BLMs as these, when combined with a cell-free system, represent a potential platform for screening the effects of drugs that act on various ion-channel genotypes.
Reconstitution of Human Ion Channels into Solvent-free Lipid Bilayers Enhanced by Centrifugal Forces Peer-reviewed

Ayumi Hirano-Iwata, Yutaka Ishinari, Miyu Yoshida, Shun Araki, Daisuke Tadaki, Ryusuke Miyata, Kenichi Ishibashi, Hideaki Yamamoto, Yasuo Kimura, Michio Niwano

BIOPHYSICAL JOURNAL　110　(10)　2207-2215　2016/05
Publisher: CELL PRESS
DOI： 10.1016/j.bpj.2016.04.010 　

ISSN：0006-3495

eISSN：1542-0086

More details Close

Artificially formed bilayer lipid membranes (BLMs) provide well-defined systems for functional analyses of various membrane proteins, including ion channels. However, difficulties associated with the integration of membrane proteins into BLMs limit the experimental efficiency and usefulness of such BLM reconstitution systems. Here, we report on the use of centrifugation to more efficiently reconstitute human ion channels in solvent-free BLMs. The method improves the probability of membrane fusion. Membrane vesicles containing the human ether-a-go-go-related gene (hERG) channel, the human cardiac sodium channel (Nav1.5), and the human GABA(A) receptor (GABA(A)R) channel were formed, and the functional reconstitution of the channels into BLMs via vesicle fusion was investigated. Ion channel currents were recorded in 67% of the BLMs that were centrifuged with membrane vesicles under appropriate centrifugal conditions (14-55 x g). The characteristic channel properties were retained for hERG, Nav1.5, and GABA(A)R channels after centrifugal incorporation into the BLMs. A comparison of the centrifugal force with reported values for the fusion force revealed that a centrifugal enhancement in vesicle fusion was attained, not by accelerating the fusion process but by accelerating the delivery of membrane vesicles to the surface of the BLMs, which led to an increase in the number of membrane vesicles that were available for fusion. Our method for enhancing the probability of vesicle fusion promises to dramatically increase the experimental efficiency of BLM reconstitution systems, leading to the realization of a BLM-based, high-throughput platform for functional assays of various membrane proteins.
Reconstitution of Human Ether-a-go-go-Related Gene Channels in Microfabricated Silicon Chips Peer-reviewed

Azusa Oshima, Ayumi Hirano-Iwata, Hideki Mozumi, Yutaka Ishinari, Yasuo Kimura, Michio Niwano

ANALYTICAL CHEMISTRY　85　(9)　4363-4369　2013/05
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/ac303484k 　

ISSN：0003-2700

More details Close

This paper reports on the reconstitution of human ether-a-go-go-related gene (hERG) channels in artificial bilayer lipid membranes (BLMs) formed in micropores fabricated in silicon chips. The hERG channels were isolated from Chinese hamster ovary cell lines expressing the channels and incorporated into the BLMs formed by a process in which the two lipid monolayers were folded into the micropores. The characteristic features of hERG channels reported by the patch-clamp method, including single-channel conductance, voltage dependence, sensitivity to typical drugs and dependence on the potassium concentration, were investigated in the BLM reconstitution system. The BLM with hERG channels incorporated exhibited a lifetime of similar to 65 h and a tolerance to repetitive solution exchanges. Such stable BLMs containing biological channels have the potential for use in a variety of applications, including high-throughput drug screening for various ion-channel proteins.
Free-Standing Lipid Bilayers in Silicon Chips-Membrane Stabilization Based on Microfabricated Apertures with a Nanometer-Scale Smoothness Peer-reviewed

Ayumi Hirano-Iwata, Kouji Aoto, Azusa Oshima, Tasuku Taira, Ryo-taro Yamaguchi, Yasuo Kimura, Michio Niwano

LANGMUIR　26　(3)　1949-1952　2010/02
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/la902522j 　

ISSN：0743-7463

More details Close

In the present study, we propose a method for preparing stable free-standing bilayer lipid membranes (BLMs). The BLMs were prepared in a microfabricated aperture with a smoothly tapered edge, which was prepared in a nanometer-thick Si(3)N(4) septum by the wet etching method. Owing to this structure, the stress oil lipid bilayers at the contact with the septum was minimized, leading to remarkable membrane stability. The BLMs were not broken by applying a constant voltage of 1 V. The membrane lifetime was 15-45 with and without an incorporated gramicidin channel. Gramicidin single-channel Currents were recorded from the same BLM preparation when the aqueous solutions surrounding the BLM were repeatedly exchanged, demonstrating the tolerance of the present BLM to repetitive solution exchanges. Such stable membranes enable analysis of channel functions under various Solution conditions from the same BLM, which will open Lip a variety of applications including a high throughput drug screening for ion channels.
Size-dependent coalescence of nanobubbles in pure water

Michio Niwano, Teng Ma, Daisuke Tadaki, Kazuki Iwata, Yasuo Kimura, Ayumi Hirano-Iwata

Colloids and Surfaces A: Physicochemical and Engineering Aspects　2024/05

DOI： 10.1016/j.colsurfa.2024.133530 　
Radical generation and bactericidal activity of nanobubbles produced by ultrasonic irradiation of carbonated water

Takayuki Mokudai, Michi Kawada, Daisuke Tadaki, Ayumi Hirano-Iwata, Hiroyasu Kanetaka, Hiroshi Fujimori, Emiko Takemoto, Michio Niwano

Ultrasonics Sonochemistry　2024/02

DOI： 10.1016/j.ultsonch.2024.106809 　
Optical Properties of Ultrathin Biohybrid Membranes: Implications for Optoelectronic Applications

Teng Ma, Kaito Watabe, Maki Komiya, Kaoru Hiramoto, Xingyao Feng, Daisuke Tadaki, Ayumi Hirano-Iwata

ACS Applied Nano Materials　2024/01/23

DOI： 10.1021/acsanm.3c04080 　
Two-dimensional water-molecule-cluster layers at nanobubble interfaces

Michio Niwano, Teng Ma, Kazuki Iwata, Daisuke Tadaki, Hideaki Yamamoto, Yasuo Kimura, Ayumi Hirano-Iwata

Journal of Colloid and Interface Science　2023/08
Publisher: Elsevier BV
DOI： 10.1016/j.jcis.2023.08.173 　

ISSN：0021-9797
Microfluidic technologies for reconstituting neuronal network functions in vitro Invited

Hideaki Yamamoto, Ayumi Hirano-Iwata, Shigeo Sato

JSAP Review　2023　230420　2023/07/06

DOI： 10.11470/jsaprev.230420 　
Time-Series Classification in Micropatterned Neuronal Network Reservoirs

Takuma Sumi, Hideaki Yamamoto, Yuichi Katori, Koki Ito, Shigeo Sato, Ayumi Hirano-Iwata

IEICE Proceeding Series　71　173-175　2022/12/12
Publisher: The Institute of Electronics, Information and Communication Engineers
DOI： 10.34385/proc.71.a5l-d-02 　

eISSN：2188-5079

More details Close

Reservoir computing provides a novel framework to understand how the dynamics within biological neuronal networks (BNNs) is linked to information processing. Here, we used micropatterned substrates to fabricate BNNs with modular topology, one of the important structural features of brain networks, and realized a reservoir system with the modular BNN. Using image and time-series classification tasks, we evaluated the reservoir computing properties of the BNN reservoirs. The results show that modularity facilitates the separation between the trajectories of the neuronal responses to different spatial patterns, pointing to the functional advantage of the animals to modular topology within the nervous systems.
New Aspects of Bilayer Lipid Membranes for the Analysis of Ion Channel Functions Peer-reviewed

Hironori Kageyama, Teng Ma, Madoka Sato, Maki Komiya, Daisuke Tadaki, Ayumi Hirano-Iwata

Membranes　12　(9)　863-863　2022/09/06
Publisher: MDPI AG
DOI： 10.3390/membranes12090863 　

eISSN：2077-0375

More details Close

The bilayer lipid membrane (BLM) is the main structural component of cell membranes, in which various membrane proteins are embedded. Artificially formed BLMs have been used as a platform in studies of the functions of membrane proteins, including various ion channels. In this review, we summarize recent advances that have been made on artificial BLM systems for the analysis of ion channel functions. We focus on two BLM-based systems, cell-membrane mimicry and four-terminal BLM systems. As a cell-membrane-mimicking system, an efficient screening platform for the evaluation of drug side effects that act on a cell-free synthesized channel has been developed, and its prospects for use in personalized medicine will be discussed. In the four-terminal BLMs, we introduce “lateral voltage” to BLM systems as a novel input to regulate channel activities, in addition to the traditional transmembrane voltages. Such state-of-the-art technologies and new system setups are predicted to pave the way for a variety of applications, in both fundamental physiology and in drug discovery.
Application of neural network based regression model to gas concentration analysis of TiO2 nanotube-type gas sensors Peer-reviewed

Kazuki Iwata, Hiroyuki Abe, Teng Ma, Daisuke Tadaki, Ayumi Hirano-Iwata, Yasuo Kimura, Shigeaki Suda, Michio Niwano

Sensors and Actuators B: Chemical　361　131732-131732　2022/06
Publisher: Elsevier BV
DOI： 10.1016/j.snb.2022.131732 　

ISSN：0925-4005
Electrochemical data mining: from information to knowledge: general discussion

Tim Albrecht, Xiangkun Elvis Cao, Dongfei Chen, Manuel Corva, Martin A. Edwards, Andrew Ewing, Stefano Fornasaro, J. Justin Gooding, Luke Gundry, Ayumi Hirano-Iwata, Grant Jeffcoat, Ali Reza Kamali, Frédéric Kanoufi, Serge G. Lemay, Ndrina Limani, Steven Linfield, Xu Liu, Si-Min Lu, Gabriel N. Meloni, Zhongqun Tian, Kristina Tschulik, Swathi Naidu Vakamulla Raghu, Hui Wei, Yi-Lun Ying

Faraday Discussions　233　58-76　2022
Publisher: Royal Society of Chemistry ({RSC})
DOI： 10.1039/D2FD90001G 　
Designing the human-centric IoT society: Cooperative industry-academic strategies for creative future connection

Yoshihiko Horio, Kiyotaka Naoe, Shigeo Sato, Yasunori Yamanouchi, Yasunari Takaura, Mitsuyuki Yamaguchi, Masato Morishima, Ayumi Hirano-Iwata

Nonlinear Theory and Its Applications, IEICE　13　(2)　197-202　2022
Publisher: Institute of Electronics, Information and Communications Engineers (IEICE)
DOI： 10.1587/nolta.13.197 　

eISSN：2185-4106
Bactericidal Activity of Bulk Nanobubbles through Active Oxygen Species Generation. International-journal Peer-reviewed

Masato Yamaguchi, Teng Ma, Daisuke Tadaki, Ayumi Hirano-Iwata, Yoshihiko Watanabe, Hiroyasu Kanetaka, Hiroshi Fujimori, Emiko Takemoto, Michio Niwano

Langmuir : the ACS journal of surfaces and colloids　2021/08/02

DOI： 10.1021/acs.langmuir.1c01578 　

More details Close

We investigated the bactericidal activity of bulk nanobubbles (NBs) using E. coli, a model bacterium. Bulk NBs were produced by forcing gas through a porous alumina membrane with an ordered arrangement of nanoscale straight holes in contact with water. NBs with different gas contents, including CO2, O2, and N2, were generated and evaluated for their bactericidal effects. The survival rate of E. coli was significantly reduced in a suspension of CO2-containing NB (CO2-NB water). The N2-NB water demonstrated a small amount of bactericidal behavior, but its impact was not as significant as that of CO2-NB water. When E. coli was retained in O2-NB water, the survival rate was even higher than that in pure water (PW). We investigated the generation of reactive oxygen species (ROS) in NB suspensions by electron spin resonance spectroscopy. The main ROS generated in the NB water were hydroxyl radicals and OH·, and the production of ROS was the strongest in CO2-NB water, which was consistent with the results of the bactericidal effect measurements. We assumed that NB mediated by ROS would exhibit bactericidal behavior and proposed a kinetic model to explain the retention time variation of the survival rate. The results calculated based on the proposed model matched closely with the experimental results.
Selective Stimulation of a Target Neuron in Micropatterned Neuronal Circuits Using a Pair of Needle Electrodes Peer-reviewed

Kouhei HATTORI, Hekiru KURAKAKE, Junko IMAI, Takuya HASHIMOTO, Mihoko ISHIDA, Koki SATO, Honoka TAKAHASHI, Soichiro OGUMA, Hideaki YAMAMOTO, Ayumi HIRANO-IWATA, Takashi TANII

Electrochemistry　89　(4)　348-354　2021/07/05
Publisher: The Electrochemical Society of Japan
DOI： 10.5796/electrochemistry.21-00032 　

ISSN：1344-3542

eISSN：2186-2451
Advances in Artificial Bilayer Lipid Membranes as a Novel Biosensing Platform: From Drug-screening to Self-assembled Devices Peer-reviewed

Teng Ma, Madoka Sato, Maki Komiya, Xingyao Feng, Daisuke Tadaki, Ayumi Hirano-Iwata

Chemistry Letters　50　(3)　418-425　2021/03/05
Publisher: The Chemical Society of Japan
DOI： 10.1246/cl.200764 　

ISSN：0366-7022

eISSN：1348-0715
Reservoir computing properties of in-silico/in-vitro modular neuronal networks

Sumi Takuma, Yamamoto Hideaki, Takemuro Taiki, Moriya Satoshi, Sato Shigeo, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2021.1　2185-2185　2021/02/26
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2021.1.0_2185 　

eISSN：2436-7613
Parallel Recordings of Transmembrane hERG Channel Currents Based on Solvent-Free Lipid Bilayer Microarray Peer-reviewed

Ryusuke Miyata, Daisuke Tadaki, Daichi Yamaura, Shun Araki, Madoka Sato, Maki Komiya, Teng Ma, Hideaki Yamamoto, Michio Niwano, Ayumi Hirano-Iwata

Micromachines　12　(1)　98-98　2021/01/19
Publisher: MDPI AG
DOI： 10.3390/mi12010098 　

eISSN：2072-666X

More details Close

The reconstitution of ion-channel proteins in artificially formed bilayer lipid membranes (BLMs) forms a well-defined system for the functional analysis of ion channels and screening of the effects of drugs that act on these proteins. To improve the efficiency of the BLM reconstitution system, we report on a microarray of stable solvent-free BLMs formed in microfabricated silicon (Si) chips, where micro-apertures with well-defined nano- and micro-tapered edges were fabricated. Sixteen micro-wells were manufactured in a chamber made of Teflon®, and the Si chips were individually embedded in the respective wells as a recording site. Typically, 11 to 16 BLMs were simultaneously formed with an average BLM number of 13.1, which corresponded to a formation probability of 82%. Parallel recordings of ion-channel activities from multiple BLMs were successfully demonstrated using the human ether-a-go-go-related gene (hERG) potassium channel, of which the relation to arrhythmic side effects following drug treatment is well recognized.
Optical transport of sub-micron lipid vesicles along a nanofiber Peer-reviewed

Takaaki Yoshino, Daichi Yamaura, Maki Komiya, Masakazu Sugawara, Yasuyoshi Mitsumori, Michio Niwano, Ayumi Hirano-Iwata, Keiichi Edamatsu, Mark Sadgrove

Optics Express　28　(26)　38527-38527　2020/12/21
Publisher: The Optical Society
DOI： 10.1364/oe.411124 　

ISSN：1094-4087

eISSN：1094-4087

More details Close

Enhanced manipulation and analysis of bio-particles using light confined in nano-scale dielectric structures has proceeded apace in the last several years. Small mode volumes, along with the lack of a need for bulky optical elements give advantages in sensitivity and scalability relative to conventional optical manipulation. However, manipulation of lipid vesicles (liposomes) remains difficult, particularly in the sub-micron diameter regime. Here we demonstrate the optical trapping and transport of sub-micron diameter liposomes along an optical nanofiber using the nanofiber mode's evanescent field. We find that nanofiber diameters below a nominal diffraction limit give optimal results. Our results pave the way for integrated optical transport and analysis of liposome-like bio-particles, as well as their coupling to nano-optical resonators. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Contribution of AMPA and NMDA receptors in the spontaneous firing patterns of single neurons in autaptic culture Peer-reviewed

Kouhei Hattori, Takeshi Hayakawa, Akira Nakanishi, Mihoko Ishida, Hideaki Yamamoto, Ayumi Hirano-Iwata, Takashi Tanii

Biosystems　198　104278-104278　2020/12
Publisher: Elsevier BV
DOI： 10.1016/j.biosystems.2020.104278 　

ISSN：0303-2647
Piezoelectric PVDF-based sensors with high pressure sensitivity induced by chemical modification of electrode surfaces Peer-reviewed

Daisuke Tadaki, Teng Ma, Shin Yamamiya, Shintaro Matsumoto, Yuji Imai, Ayumi Hirano-Iwata, Michio Niwano

Sensors and Actuators A: Physical　316　112424-112424　2020/12
Publisher: Elsevier BV
DOI： 10.1016/j.sna.2020.112424 　

ISSN：0924-4247

More details Close

Poly(vinylidene fluoride)(PVDF), an organic piezoelectric polymer, has been extensively studied for application in flexible pressure sensors. In order to obtain a sufficient voltage output from PVDF-based pressure sensors, a poling treatment of PVDF films is necessary. Conventional poling methods generally require the application of a considerably high electric field and high annealing temperatures, which lead to an increase in the cost of sensor fabrication. Herein, we propose a method for the formation of poled PVDF films by drop-casting a PVDF-dissolved polar solution onto chemically modified electrodes and subsequent drying of the dropped solution. The PVDF-based pressure sensors in which the underlying gold (Au) electrode was modified with a thiol reagent, 1H,1H,2H,2H-Perfluorodecanethiol (PFDT), exhibited a remarkably high pressure sensitivity, while negligible sensitivity was achieved without surface modification. It was demonstrated that surface chemical modification aligns the direction of the surface dipoles. The proposed method is advantageous for controlling the polarization of PVDF films on electrode surfaces. (C) 2020 Elsevier B.V. All rights reserved.
Polydimethylsiloxane microfluidic films for in vitro engineering of small-scale neuronal networks Peer-reviewed

Taiki Takemuro, Hideaki Yamamoto, Shigeo Sato, Ayumi Hirano-Iwata

Japanese Journal of Applied Physics　59　(11)　117001-117001　2020/11/01
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/abc1ac 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

Polydimethylsiloxane microfluidic devices have become standard tools in cell engineering research. However, through-holes where cells access the microchannels are usually fabricated manually using biopsy punches, making it difficult to create a large array of sub-mm sized through-holes. Here, we present a fabrication process for a thin-film microfluidic device containing an array of through-holes, which are as small as 100 μm by 100 μm and span 10 mm by 10 mm. A proof-of-concept application of the device to neuronal patterning experiments shows that spatially complex network dynamics emerge when a non-random connectivity is imposed to cultured neuronal networks. We also demonstrate that the coupling strengths between neuronal modules, a major factor that defines the global network dynamics, can be effectively modulated by varying the microchannel widths. This work opens a new application of microfluidic devices to multicellular systems comprised of several tens to hundreds of neurons.
Bactericidal Activity of TiO2 Nanotube Thin Films on Si by Photocatalytic Generation of Active Oxygen Species Peer-reviewed

Masato Yamaguchi, Hiroyuki Abe, Teng Ma, Daisuke Tadaki, Ayumi Hirano-Iwata, Hiroyasu Kanetaka, Yoshihiko Watanabe, Michio Niwano

Langmuir　36　(42)　12668-12677　2020/10/27
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.langmuir.0c02225 　

ISSN：0743-7463

eISSN：1520-5827
Establishment of a cell-free translation system from rice callus extracts Peer-reviewed

Kakeru Suzuki, Haruka Inoue, Satoshi Matsuoka, Ryugo Tero, Ayumi Hirano-Iwata, Yuzuru Tozawa

Bioscience, Biotechnology, and Biochemistry　84　(10)　2028-2036　2020/10/02
Publisher: Oxford University Press (OUP)
DOI： 10.1080/09168451.2020.1779024 　

ISSN：0916-8451

eISSN：1347-6947

More details Close

<title>Abstract</title> Eukaryotic in vitro translation systems require large numbers of protein and RNA components and thereby rely on the use of cell extracts. Here we established a new in vitro translation system based on rice callus extract (RCE). We confirmed that RCE maintains its initial activity even after five freeze-thaw cycles and that the optimum temperature for translation is around 20°C. We demonstrated that the RCE system allows the synthesis of hERG, a large membrane protein, in the presence of liposomes. We also showed that the introduction of a bicistronic mRNA based on 2A peptide to RCE allowed the production of two distinct proteins from a single mRNA. Our new method thus facilitates laboratory-scale production of cell extracts, making it a useful tool for the in vitro synthesis of proteins for biochemical studies.
Response characteristics of a highly sensitive gas sensor using a titanium oxide nanotube film decorated with platinum nanoparticles Peer-reviewed

Hiroyuki Abe, Yasuo Kimura, Teng Ma, Daisuke Tadaki, Ayumi Hirano-Iwata, Michio Niwano

Sensors and Actuators B: Chemical　321　128525-128525　2020/10
Publisher: Elsevier BV
DOI： 10.1016/j.snb.2020.128525 　

ISSN：0925-4005
Characterization of Bulk Nanobubbles Formed by Using a Porous Alumina Film with Ordered Nanopores Peer-reviewed

Teng Ma, Yasuo Kimura, Hideaki Yamamoto, Xingyao Feng, Ayumi Hirano-Iwata, Michio Niwano

The Journal of Physical Chemistry B　124　(24)　5067-5072　2020/06/18
Publisher: American Chemical Society ({ACS})
DOI： 10.1021/acs.jpcb.0c02279 　

ISSN：1520-6106

eISSN：1520-5207
Capacitance extraction method for a free-standing bilayer lipid membrane formed over an aperture in a nanofabricated silicon chip Peer-reviewed

Yasutaka Tomioka, Shogo Takashima, Masataka Moriya, Hiroshi Shimada, Fumihiko Hirose, Ayumi Hirano-Iwata, Yoshinao Mizugaki

Japanese Journal of Applied Physics　59　(SI)　SIIK02-SIIK02　2020/06/01
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ab79f0 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

© 2020 The Japan Society of Applied Physics. A bilayer lipid membrane (BLM) is the main component of the cell membrane of living organisms, which can be formed artificially. Although the specific capacitance of a BLM is known to be in the range of 0.4-1.0 μF cm-2, many previous works that formed free-standing BLMs over an aperture in silicon chips reported larger values beyond this typical range, which suggests that equivalent-circuit models are not adequate. In this work, we modified the equivalent-circuit model by adding a resistance element of silicon. To evaluate the validity of the modified model, we applied the model to the results of electrochemical impedance spectroscopy for free-standing BLMs formed over an aperture in nanofabricated silicon chips. The derived specific capacitance values were 0.57 ± 0.08 μF cm-2, which settles in the typical range.
Self-Assembly of Hybrid Lipid Membranes Doped with Hydrophobic Organic Molecules at the Water/Air Interface Peer-reviewed

Xingyao Feng, Teng Ma, Daisuke Tadaki, Ayumi Hirano-Iwata

Journal of Visualized Experiments　(159)　2020/05/01
Publisher: MyJove Corporation
DOI： 10.3791/60957 　

eISSN：1940-087X
Printed 3D Electrode Arrays with Micrometer‐Scale Lateral Resolution for Extracellular Recording of Action Potentials Peer-reviewed

Leroy Grob, Hideaki Yamamoto, Sabine Zips, Philipp Rinklin, Ayumi Hirano‐Iwata, Bernhard Wolfrum

Advanced Materials Technologies　5　(3)　1900517-1900517　2020/03
Publisher: Wiley
DOI： 10.1002/admt.201900517 　
Impact of electrical field noise on micropatterned neuronal networks

Sumi Takuma, Yamamoto Hideaki, Wakimura Kei, Sato Shigeo, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2020.1　3653-3653　2020/02/28
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2020.1.0_3653 　

eISSN：2436-7613
Modular networks of spiking neurons for applications in time-series information processing

Satoshi Moriya, Hideaki Yamamoto, Ayumi Hirano-Iwata, Shigeru Kubota, Shigeo Sato

Nonlinear Theory and Its Applications, IEICE　11　(4)　590-600　2020
Publisher: Institute of Electronics, Information and Communications Engineers (IEICE)
DOI： 10.1587/nolta.11.590 　

eISSN：2185-4106
Dielectrophoretic assembly of gold nanoparticle arrays evaluated in terms of room-temperature resistance

Yoshinao Mizugaki, Makoto Moribayashi, Tomoki Yagai, Masataka Moriya, Hiroshi Shimada, Ayumi Hirano-Iwata, Fumihiko Hirose

IEICE Transactions on Electronics　E103C　(2)　62-65　2020

DOI： 10.1587/transele.2019ECS6011 　

ISSN：0916-8524

eISSN：1745-1353

More details Close

Copyright © 2020 The Institute of Electronics, Information and Communication Engineers Gold nanoparticles (GNPs) are often used as island electrodes of single-electron (SE) devices. One of technical challenges in fabrication of SE devices with GNPs is the placement of GNPs in a nanogap between two lead electrodes. Utilization of dielectrophoresis (DEP) phenomena is one of possible solutions for this challenge, whereas the fabrication process with DEP includes stochastic aspects. In this brief paper, we present our experimental results on electric resistance of GNP arrays assembled by DEP. More than 300 pairs of electrodes were investigated under various DEP conditions by trial and error approach. We evaluated the relationship between the DEP conditions and the electric resistance of assembled GNP arrays, which would indicate possible DEP conditions for fabrication of SE devices.
Suppression of hypersynchronous network activity in cultured cortical neurons using an ultrasoft silicone scaffold International-journal Peer-reviewed

Takuma Sumi, Hideaki Yamamoto, Ayumi Hirano-Iwata

Soft Matter　16　(13)　3195-3202　2020
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/c9sm02432h 　

ISSN：1744-683X

eISSN：1744-6848

More details Close

An ultrasoft silicone elastomer as an alternative substrate for neuronal culture is investigated.
Development of Multifunctional Ultrathin Films Based on Lipid Bilayer Structures Formed on Microfabricated Chips Peer-reviewed

Teng Ma, Madoka Sato, Daisuke Tadaki, Xingyao Feng, Ayumi Hirano-Iwata

MEMBRANE　45　(3)　121-128　2020
Publisher: The Membrane Society of Japan
DOI： 10.5360/membrane.45.121 　

ISSN：0385-1036

eISSN：1884-6440
Ultrasoft Silicone Gel as a Biomimetic Passivation Layer in Inkjet‐Printed 3D MEA Devices Peer-reviewed

Hideaki Yamamoto, Leroy Grob, Takuma Sumi, Kazuhiro Oiwa, Ayumi Hirano‐Iwata, Bernhard Wolfrum

Advanced Biosystems　3　(9)　1900130-1900130　2019/09
Publisher: Wiley
DOI： 10.1002/adbi.201900130 　
Proteoliposome fusion to artificial lipid bilayer promoted by domains of polyunsaturated phosphatidylethanolamine Peer-reviewed

Melvin Wei Shern Goh, Ayumi Hirano-Iwata, Michio Niwano, Ryugo Tero

Japanese Journal of Applied Physics　58　({SI})　SIIB13　2019/08/01
Publisher: {IOP} Publishing
DOI： 10.7567/1347-4065/ab1397 　
Formation and Characterization of Air-Stable Lipid Bilayer Membranes Incorporated with Phthalocyanine Molecules Peer-reviewed

Xingyao Feng, Teng Ma, Daichi Yamaura, Daisuke Tadaki, Ayumi Hirano-Iwata

The Journal of Physical Chemistry B　123　(30)　6515-6520　2019/08/01
Publisher: American Chemical Society ({ACS})
DOI： 10.1021/acs.jpcb.9b05135 　
A Teflon-based system for applying multidirectional voltages to lipid bilayers as a novel platform for membrane proteins

Maki Komiya, Kensaku Kanomata, Ryo Yokota, Yusuke Tsuneta, Madoka Sato, Daichi Yamaura, Daisuke Tadaki, Teng Ma, Hideaki Yamamoto, Yuzuru Tozawa, Albert Marti, Jordi Madrenas, Shigeru Kubota, Fumihiko Hirose, Michio Niwano, Ayumi Hirano-Iwata

2019/07/12

More details Close

Artificial bilayer lipid membranes (BLMs), along with patch-clamped membranes, are frequently used for functional analyses of membrane proteins. In both methods, the electric properties of membranes are characterized by only one parameter, namely, transmembrane potential. Here the construction of a novel BLM system was reported, in which membrane voltages can be controlled in a lateral direction in addition to conventional transmembrane direction. A microaperture was fabricated in a Teflon film and Ti electrodes were evaporated around the aperture. BLMs were reproducibly formed in the aperture without being affected by the presence of the electrodes. The application of a lateral voltage induced no significant changes in the electric properties of the BLMs, such as baseline current, transmembrane resistance, and transmembrane capacitance. In contrast, lateral voltages clearly affected the activities of biological ion channels, suggesting that the lateral voltage might be a useful parameter for analyzing channel activities. The present Teflon-based system in which multidirectional voltages can be applied to BLMs represent a promising platform for the analysis of underlying functional properties of membrane proteins.
Equivalent circuit model modified for free-standing bilayer lipid membranes beyond 1 teraohm Peer-reviewed

Yasutaka Tomioka, Shogo Takashima, Masataka Moriya, Hiroshi Shimada, Fumihiko Hirose, Ayumi Hirano-Iwata, Yoshinao Mizugaki

Japanese Journal of Applied Physics　58　(SD)　SDDK02-1-SDDK02-6　2019/04

DOI： 10.7567/1347-4065/ab088c 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

© 2019 The Japan Society of Applied Physics. A cell is the basic functional unit of living organisms. Bilayer lipid membranes (BLMs), which form cell membranes can be assembled by using artificial methods. The electrochemical characteristics of BLMs are normally investigated using electrochemical impedance spectroscopy (EIS); however, the equivalent circuit need to be modified by the experimental conditions. In this study, we formed plain BLMs to determine the underlying equivalent circuit model of free-standing BLMs, and we measured the electrical characteristics using EIS. To analyze the results of EIS, we proposed equivalent circuit models including electrical double layer (EDL) effects on both sides of a BLM. We also extracted and evaluated the electrochemical parameters; the aperture-suspended BLMs using an Si chip having tapered edge recorded TΩ-order membrane resistances, which were one order higher than those reported in most previous studies. Regarding the capacitances of EDL, we compared the extracted values and the calculated results.
Analysis of ion channel openings using bilayer lipid membranes

Yokota Ryo, Hirano-Iwata Ayumi, Tsuneta Yusuke, Sato Madoka, Kato Miki, Yamaura Daichi, Tadaki Daisuke, Komiya Maki, Yamamoto Hideaki, Niwano Michio

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2019　(0)　2P56　2019
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/jvss.2019.0_2P56 　

More details Close
Evaluation of the inter-particle distance of gold nanoparticles dispersed on silane-treated substrates to fabricate dithiol-connected arrays Peer-reviewed

Tomoki Yagai, Kazuhiko Matsumoto, Makoto Moribayashi, Masataka Moriya, Hiroshi Shimada, Ayumi Hirano-Iwata, Fumihiko Hirose, Yoshinao Mizugaki

Japanese Journal of Applied Physics　58　(SD)　2019

DOI： 10.7567/1347-4065/ab1476 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

© 2019 The Japan Society of Applied Physics. Small tunnel junctions using gold nanoparticles (GNPs) as electrodes have been studied to fabricate single-electron devices. GNPs connected via dithiol molecules have been used as small tunnel junctions, and a two-stage dispersion method was used to fabricate dithiol-connected GNP arrays. In this process, the GNPs were fixed on silane-treated substrates by immersing the substrate in a colloidal gold solution. For fabricating dithiol-connected arrays, the inter-particle distance of the dispersed GNPs must be smaller than the GNP diameter. Consequently, the inter-particle distance controlled by the immersion time (T IM1) was evaluated. For T IM1 values exceeding 8 h, the inter-particle distance was less than the GNP diameter. A second dispersion of GNPs after treating samples with dithiol realized particle connections. For the GNP arrays produced with T IM1 values greater than 8 h, the I-V characteristics were measured at 77 K, and the yield of devices exhibiting nonlinear I-V curves was 23%.
Temporal change of AC impedance measured across a free-standing bilayer lipid membrane Peer-reviewed

S. Takashima, M. Moriya, Y. Kimura, A. Hirano-Iwata, Y. Mizugaki

AIP Conference Proceedings　2067　020015-1-020015-5　2019/01
Single-electron charging effects observed in arrays of gold nanoparticles formed by dielectrophoresis between SAM-coated electrodes Peer-reviewed

M. Moribayashi, T. Yagai, M. Moriya, H. Shimada, A. Hirano-Iwata, F. Hirose, Y. Mizugaki

AIP Conference Proceedings　2067　020019-1-020019-8　2019/01

DOI： 10.1063/1.5089452 　

ISSN：0094-243X

eISSN：1551-7616

More details Close

© 2019 Author(s). In the fabrication of single-electron (SE) devices with gold nanoparticles (GNPs), one of the technical challenges is the arrangement of GNPs into a gap between electrodes. We employed dielectrophoresis (DEP) for the GNP arrangement because it allowed flexible fabrication conditions. When we tried to arrange GNPs into a gap between electrodes, we often had an excessive current during DEP, which resulted in poor fabrication yields. It suggested that the Joule heat generated by the excessive current could break or fused arrays of GNPs when the electrodes were bridged through the arrays. In order to solve this problem, we coated the electrode surfaces with a self-assembled monolayer (SAM) of dithiol, by which high resistance between GNPs and electrodes was realized. That is, suppression of excess currents and improvement of fabrication yield were confirmed. We also demonstrated that a sample device fabricated by using this method exhibited not only the Coulomb blockade but also the Coulomb oscillation.
Mean-field analysis of directed modular networks Peer-reviewed

Satoshi Moriya, Hideaki Yamamoto, Hisanao Akima, Ayumi Hirano-Iwata, Shigeru Kubota, Shigeo Sato

Chaos: An Interdisciplinary Journal of Nonlinear Science　29　(1)　013142-013142　2019/01
Publisher: {AIP} Publishing
DOI： 10.1063/1.5044689 　
In Situ Infrared Observation of a Photo-Decomposition Process of Organic Contaminants on a TiO2 Nanotube Film Surface Peer-reviewed

Teng Ma, Yasuo Kimura, Daisuke Tadaki, Ayumi Hirano-Iwata, Michio Niwano

Journal of The Electrochemical Society　166　(15)　H842-H848　2019
Publisher: The Electrochemical Society
DOI： 10.1149/2.1151915jes 　

ISSN：0013-4651

eISSN：1945-7111
Photomodulation of electrical conductivity of a PCBM-doped free-standing lipid bilayer in buffer solution Peer-reviewed

Kensaku Kanomata, Takafumi Deguchi, Teng Ma, Takumi Haseyama, Masanori Miura, Daichi Yamaura, Daisuke Tadaki, Michio Niwano, Ayumi Hirano-Iwata, Fumihiko Hirose

Journal of Electroanalytical Chemistry　832　55-58　2019/01
Publisher: Elsevier BV
DOI： 10.1016/j.jelechem.2018.10.039 　

ISSN：1572-6657
【膜】人工細胞膜を用いたイオンチャネルタンパク質解析系の開発個別化医療のためのhERGチャネル薬物副作用評価を目指して

小宮麻希, 馬騰, 但木大介, 平野愛弓

分析化学　67　(12)　749-760　2018/12
Publisher: (公社)日本分析化学会
DOI： 10.2116/bunsekikagaku.67.749 　

ISSN：0525-1931

More details Close

心筋細胞の細胞膜中に多く存在するカリウムイオンチャネルhERGの機能阻害は、QT延長症や不整脈など命にかかわるような心疾患の発症と関連している。hERGチャネルの阻害は先天的な遺伝子異常だけではなく、薬剤による副作用によっても引き起こされる。hERGチャネルの遺伝子型によって薬剤化合物との反応性は異なり、各々の患者に対して安全な薬を処方するためにはその患者のhERG遺伝子型に応じて副作用を引き起こさない薬剤の選択(個別化医療)が必要とされる。著者らは、各遺伝子型に応じhERGチャネルを阻害する薬剤化合物の網羅的・包括的な同定法の開発を目指し、人工細胞膜を用いたイオンチャネルの解析系の開発に努めてきた。従来、人工細胞膜系においては、その膜の脆弱性や膜へのイオンチャネルの包埋率の低さなどが大きな課題となっていた。著者らはこれらの諸問題に対し、様々なアプローチをとることで解決を図ってきた。本論文では、著者らが開発している人工細胞膜を用いたイオンチャネルの解析系と上述の諸問題に対するアプローチについて最新の研究成果を中心に紹介したい。(著者抄録)
Development of an Analytical System for Ion Channel Proteins Based on Artificial Bilayer Lipid Membranes -Screening of Drug Components that Haveing Side Effects on hERG Channels for Personalized Medicine- Peer-reviewed

Komiya Maki, Ma Teng, Tadaki Daisuke, Hirano-Iwata Ayumi

BUNSEKI KAGAKU　67　(12)　749-760　2018/12
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/bunsekikagaku.67.749 　

ISSN：0525-1931

More details Close

The human ether-a-go-go related gene (hERG) channel is a cardiac voltage-dependent potassium channel, which plays a key role in action potential generation in the heart. Since a diverse group of drugs can adversely block hERG channels, and can sometimes induce life-threatening arrhythmias, it is highly important to develop an efficient system for assessing the potential risks of such drug side effects on the hERG channel. An artificially formed bilayer lipid membrane (BLM) with the incorporated ion channels is a strong candidate for this assay platform. However, two major problems associated with BLM systems reduce their experimental efficiency, namely, the instability of BLMs and a low efficiency of ion channel incorporation into BLMs. In this paper, we will discuss our recent approaches to address these issues through the combination with silicon (Si) microfabrication techniques, and also discuss the application of the BLM systems to a hERG assay platform. Mechanically stable solvent-free BLMs were formed in microapertures fabricated in Si chips. The edge of the aperture was tapered in both nano- and micro-meter scales, leading to a smooth contact between the BLMs and the aperture wall. Another approach for improving the stability of BLMs is based on surface modification of the Si chips. It was found that highly stable BLMs were formed in amphiphobic Si chips that had been treated with long-chain perfluorocarbons. Owing to the mechanical stability of the BLMs, we also developed a centrifugal method for the efficient incorporation of human ion channels, including hERG channels, into solvent-free BLMs. The method improves the probability of vesicle fusion between the BLMs and channel-containing proteoliposomes. We also combined the BLM system with cell-free protein synthesis. Single-channel currents of a cell-free synthesized hERG channel were clearly recorded. The channel currents were blocked by the addition of an antihistamine astemizole, whose adverse effect on the hERG channel is well-established. When the present stable BLM system is combined with various hERG channel genotypes, it will provide a potential platform for assessing the risks of drug side effects acting on hERG channels of each patient.
Numerical simulation of single-electron tunneling in random arrays of small tunnel junctions formed by percolation of conductive nanoparticles Peer-reviewed

Y. Mizugaki, H. Shimada, A. Hirano-Iwata, F. Hirose

IEICE Transactions on Electronics　E101-C　(10)　836-839　2018/10

DOI： 10.1587/transele.E101.C.836 　

ISSN：0916-8524

eISSN：1745-1353

More details Close

Copyright © 2018 The Institute of Electronics, Information and Communication Engineers. We numerically simulated electrical properties, i.e., the resistance and Coulomb blockade threshold, of randomly-placed conductive nanoparticles. In simulation, tunnel junctions were assumed to be formed between neighboring particle-particle and particle-electrode connections. On a plane of triangle 100 × 100 grids, three electrodes, the drain, source, and gate, were defined. After random placements of conductive particles, the connection between the drain and source electrodes were evaluated with keeping the gate electrode disconnected. The resistance was obtained by use of a SPICE-like simulator, whereas the Coulomb blockade threshold was determined from the current-voltage characteristics simulated using a Monte-Carlo simulator. Strong linear correlation between the resistance and threshold voltage was confirmed, which agreed with results for uniform one-dimensional arrays.
Photomodulation of electrical conductivity of a PCBM-doped free-standing lipid bilayer in buffer solution Peer-reviewed

K. Kanomata, T. Deguchi, T. Ma, T. Haseyama, M. Miura, D. Yamaura, D. Tadaki, M. Niwano, A. Hirano-Iwata, F. Hirose

J. Elecroanal. Chem.　832　55-58　2018/10
A single-cell based hybrid neuronal network configured by integration of cell micropatterning and dynamic patch-clamp Peer-reviewed

Hideaki Yamamoto, Takeshi Hayakawa, Theoden I. Netoff, Ayumi Hirano-Iwata

Applied Physics Letters　113　(13)　133703-133703　2018/09/24
Publisher: {AIP} Publishing
DOI： 10.1063/1.5049487 　
One-dimensional array of small tunnel junctions fabricated using 30-nm-diameter gold nanoparticles placed in a 140-nm-wide resist groove Peer-reviewed

Yoshinao Mizugaki, Kazuhiko Matsumoto, Masataka Moriya, Hiroshi Shimada, Ayumi Hirano-Iwata, Fumihiko Hirose

Japanese Journal of Applied Physics　57　(9)　098006-1-098006-3　2018/08

DOI： 10.7567/JJAP.57.098006 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

© 2018 The Japan Society of Applied Physics. We present percolative arrays of gold nanoparticles (NPs) formed in a resist groove. To enhance the connection probability, the width of the resist groove (140 nm) was designed to be approximately five times larger than the diameter of gold NPs (30 nm). Two-stage deposition of gold NPs was employed to form bridge connections between the source and drain electrodes. Dithiol molecules coated on surfaces of gold NPs worked as tunnel barriers. 5 of 12 samples exhibited Coulomb blockade characteristics, in one of which the gate response was confirmed.
Dependence and Homeostasis of Membrane Impedance on Cell Morphology in Cultured Hippocampal Neurons Peer-reviewed

Sci. Rep.　8　9905-1-9905-10　2018/07
Host Cell Prediction of Exosomes Using Morphological Features on Solid Surfaces Analyzed by Machine Learning Peer-reviewed

Kazuki Ito, Yuta Ogawa, Keiji Yokota, Sachiko Matsumura, Tamiko Minamisawa, Kanako Suga, Kiyotaka Shiba, Yasuo Kimura, Ayumi Hirano-Iwata, Yuzuru Takamura, Toshio Ogino

Journal of Physical Chemistry B　122　(23)　6224-6235　2018/06/14
Publisher: American Chemical Society
DOI： 10.1021/acs.jpcb.8b01646 　

ISSN：1520-5207 1520-6106

More details Close

Exosomes are extracellular nanovesicles released from any cells and found in any body fluid. Because exosomes exhibit information of their host cells (secreting cells), their analysis is expected to be a powerful tool for early diagnosis of cancers. To predict the host cells, we extracted multidimensional feature data about size, shape, and deformation of exosomes immobilized on solid surfaces by atomic force microscopy (AFM). The key idea is combination of support vector machine (SVM) learning for individual exosome particles and their interpretation by principal component analysis (PCA). We observed exosomes derived from three different cancer cells on SiO2/Si, 3-aminopropyltriethoxysilane-modified-SiO2/Si, and TiO2 substrates by AFM. Then, 14-dimensional feature vectors were extracted from AFM particle data, and classifiers were trained in 14-dimensional space. The prediction accuracy for host cells of test AFM particles was examined by the cross-validation test. As a result, we obtained prediction of exosome host cells with the best accuracy of 85.2% for two-class SVM learning and 82.6% for three-class one. By PCA of the particle classifiers, we concluded that the main factors for prediction accuracy and its strong dependence on substrates are incremental decrease in the PCA-defined aspect ratio of the particles with their volume.
Amphiphobic Septa Enhance the Mechanical Stability of Free-Standing Bilayer Lipid Membranes Peer-reviewed

Daichi Yamaura, Daisuke Tadaki, Shun Araki, Miyu Yoshida, Kohei Arata, Takeshi Ohori, Ken-ichi Ishibashi, Miki Kato, Teng Ma, Ryusuke Miyata, Hideaki Yamamoto, Ryugo Tero, Masao Sakuraba, Toshio Ogino, Michio Niwano, Ayumi Hirano-Iwata

LANGMUIR　34　(19)　5615-5622　2018/05
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/acs.langmuir.8b00747 　

ISSN：0743-7463

More details Close

Artificial bilayer lipid membranes (BLMs) provide well-defined systems for investigating the fundamental properties of membrane proteins, including ion channels, and for screening the effect of drugs that act on them. However, the application of this technique is limited due to the low stability and low reconstitution efficiency of the process. We previously reported on improving the stability of BLM based on the fabrication of microapertures having a tapered edge in SiO2/Si3N4 septa and efficient ion channel incorporation based on vesicle fusion accelerated by a centrifugal force. Although the BLM stability and incorporation probability were dramatically improved when these approaches were used, some BLMs were ruptured when subjected to a centrifugal force. To further improve the BLM stability, we investigated the effect of modifying the surface of the SiO2/Si3N4 septa on the stability of BLM suspended in the septa. The modified surfaces were characterized in terms of hydrophobicity, lipophobicity, and surface roughness. Diffusion coefficients of the lipid monolayers formed on the modified surfaces were also determined. Highly fluidic lipid monolayers were formed on the amphiphobic substrates that had been modified with long-chain perfluorocarbons. Free-standing BLMs formed in amphiphobic septa showed a much higher mechanical stability, including tolerance to water movement and applied centrifugal forces with and without proteoliposomes, than those formed in the septa that had been modified with a short alkyl chain. These results demonstrate that highly stable BLMs are formed when the surface of the septa has amphiphobic properties. Because highly fluidic lipid monolayers that are formed on the septa seamlessly connect with BLMs in a free-standing region, the high fluidity of the lipids contributes to decreasing potential damage to BLMs when mechanical stresses are applied. This approach to improve the BLM stability increases the experimental efficiency of the BLM systems and will contribute to the development of high-throughput platforms for functional assays of ion channel proteins.
Unveil the Full Potential of Integrated-Back-Contact Perovskite Solar Cells Using Numerical Simulation Peer-reviewed

Teng Ma, Qingwen Song, Daisuke Tadaki, Michio Niwano, Ayumi Hirano-Iwata

ACS Appl. Energy Mater.　1　(3)　970-975　2018/03
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/acsaem.8b00044 　

ISSN：2574-0962

More details Close

The technologies of perovskite solar cells (PSCs) have been developing rapidly. After 8 years of research, the quantum efficiency of PSCs based on the planar sandwich structure has been approaching 100% in the visible light region. In order to further improve the performance of PSCs, adopting an integrated-back-contact (IBC) structure, which is expected to be able to reduce light loss, to the PSCs is a promising option. In this work, a numerical simulation method is, for the first time, used to verify the applicability of the IBC structure to PSCs. We have investigated the factors that may affect the power conversion efficiency of the IBC-PSCs, to demonstrate that IBC-PSCs are advantageous over the traditional sandwich PSCs when we use small contact width (<= 5 mu m) of the IBC-PSCs and reported characteristics of perovskite films (mobility >= 10 cm(2) V-1 s(-1), lifetime >= 1 mu s) in the simulation. By optimizing the properties of perovskite films, we can fabricate IBC-PSCs with 11% of improved performance over that of the sandwich-type PSCs. The present results provide guidelines for the design and fabrication of highly efficient IBC-PSCs.
Effective Subnetwork Topology for Synchronizing Interconnected Networks of Coupled Phase Oscillators Peer-reviewed

Hideaki Yamamoto, Shigeru Kubota, Fabio A. Shimizu, Ayumi Hirano-Iwata, Miciho Niwano

Front. Comput. Neurosci.　12　(1)　17-1-17-10　2018/03
In situ modification of cell-culture scaffolds by photocatalysis of visible-light-responsive TiO2 film Peer-reviewed

Sho Kono, Kohei Furusawa, Atsushi Kurotobi, Kohei Hattori, Hideaki Yamamoto, Ayumi Hirano-Iwata, Takashi Tanii

Japanese Journal of Applied Physics　57　(2)　027001-1-027001-6　2018/02/01
Publisher: Japan Society of Applied Physics
DOI： 10.7567/JJAP.57.027001 　

ISSN：1347-4065 0021-4922

More details Close

We propose a novel process to modify the cell affinity of scaffolds in a cell-culture environment using the photocatalytic activity of visible-light (VL)-responsive TiO2. The proposed process is the improved version of our previous demonstration in which ultraviolet (UV)-responsive TiO2 was utilized. In that demonstration, we showed that cell-repellent molecules on TiO2 were decomposed and replaced with cell-permissive molecules upon UV exposure in the medium where cells are being cultured. However, UV irradiation involves taking the risk of inducing damage to the cells. In this work, a TiO2 film was sputter-deposited on a quartz coverslip at 640 °C without O2 gas injection to create a rutile structure containing oxygen defects, which is known to exhibit photocatalytic activity upon VL exposure. We show that the cell adhesion site and migration area can be controlled with the photocatalytic activity of the VL-responsive TiO2 film, while the cellular oxidative stress is reduced markedly by the substitution of VL for UV.
Quantification of Drug Side Effects on Cell-Free Synthesized Ion-Channels Reconstituted in Bilayer Lipid Membranes

Kato Miki, Hirano Ayumi, Inoue Haruka, Yamaura Daichi, Yokota Reo, Komiya Maki, Tadaki Daisuke, Yamamoto Hidaka, Tozawa Yuzuru, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　2018　(0)　181-181　2018
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/sssj2008.2018.0_181 　

More details Close

We aim to develop a drug screening system based on a reconstitution system in which ion channels are embedded in an artificial lipid bilayer membrane (BLM). We have been developing stable BLMs based on silicon (Si) microfabrication. We previously reported on efficient incorporation of ion channels in BLMs. Here we applied this system to a cell-free synthesized hERG channel and tried to quantify drug side effects on this channel.
Gold surface modification for control of polarization in PVDF films

Yamamiya Shin, Tadaki Daisuke, Ma Teng, Imai Yuji, Hirano-Iwata Ayumi, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　2018　(0)　17-17　2018
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/sssj2008.2018.0_17 　
Formation of Cell Membrane Component Domains in Artificial Lipid Bilayer Peer-reviewed

Ryugo Tero, Kohei Fukumoto, Toshinori Motegi, Miyu Yoshida, Michio Niwano, Ayumi Hirano-Iwata

SCIENTIFIC REPORTS　7　17905　2017/12
Publisher: NATURE PUBLISHING GROUP
DOI： 10.1038/s41598-017-18242-9 　

ISSN：2045-2322

More details Close

The lipid bilayer environment around membrane proteins strongly affects their structure and functions. Here, we aimed to study the fusion of proteoliposomes (PLs) derived from cultured cells with an artificial lipid bilayer membrane and the distribution of the PL components after the fusion. PLs, which were extracted as a crude membrane fraction from Chinese hamster ovary (CHO) cells, formed isolated domains in a supported lipid bilayer (SLB), comprising phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cholesterol (Chol), after the fusion. Observation with a fluorescence microscope and an atomic force microscope showed that the membrane fusion occurred selectively at microdomains in the PC + PE + Chol-SLB, and that almost all the components of the PL were retained in the domain. PLs derived from human embryonic kidney 293 (HEK) cells also formed isolated domains in the PC + PE + Chol-SLB, but their fusion kinetics was different from that of the CHO-PLs. We attempted to explain the mechanism of the PL-SLB fusion and the difference between CHO- and HEK-PLs, based on a kinetic model. The domains that contained the whole cell membrane components provided environments similar to that of natural cell membranes, and were thus effective for studying membrane proteins using artificial lipid bilayer membranes.
Charge transport properties of bulk-heterojunction organic solar cells investigated by displacement current measurement technique Peer-reviewed

Teng Ma, Jinyu Zhang, Daisuke Tadaki, Yasuo Kimura, Ayumi Hirano-Iwata, Michio Niwano

ORGANIC ELECTRONICS　51　269-276　2017/12
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.orgel.2017.09.020 　

ISSN：1566-1199

eISSN：1878-5530

More details Close

We have investigated charge transport properties of bulk-heterojunction (BH) solar cells in which P3HT (Poly(3-hexylthiophene)) and PCBM ([6,6]-phenyl-C-61-butyric acid methyl ester) are used as the active layer, by using the displacement current measurement (DCM) method. In order to investigate the charge transport properties of the BH solar cells, we fabricated a dedicated device that consists of P3HT and PCBM, and used the DCM method to measure the charge distribution of the devices with different composition ratios of P3HT and PCBM. DCM data suggested that a BH film with 50 wt% of PCBM exhibits a preferable charge transport property suited for BH solar cells. We confirmed that the DCM results are consistent with the measured performance of the BH solar cells, indicating that the DCM method is a simple and effective method for optimizing the structure of BH solar cells as well as other electronic devices composed of binary materials. (C) 2017 Elsevier B.V. All rights reserved.
Astrocytes with previous chronic exposure to amyloid β-peptide fragment 1-40 suppress excitatory synaptic transmission. International-journal Peer-reviewed

Hiroyuki Kawano, Kohei Oyabu, Hideaki Yamamoto, Kei Eto, Yuna Adaniya, Kaori Kubota, Takuya Watanabe, Ayumi Hirano-Iwata, Junichi Nabekura, Shutaro Katsurabayashi, Katsunori Iwasaki

Journal of neurochemistry　143　(6)　624-634　2017/12

DOI： 10.1111/jnc.14247 　

More details Close

Synaptic dysfunction and neuronal death are responsible for cognitive and behavioral deficits in Alzheimer's disease (AD). It is well known that such neurological abnormalities are preceded by long-term exposure of amyloid β-peptide (Aβ) and/or hyperphosphorylated tau prior. In addition to the neurological deficit, astrocytes as a major glial cell type in the brain, significantly participate in the neuropathogenic mechanisms underlying synaptic modulation. Although astrocytes play a significant key role in modulating synaptic transmission, little is known on whether astrocyte dysfunction caused by such long-term Aβ exposure affects synapse formation and function. Here, we show that synapse formation and synaptic transmission are attenuated in hippocampal-naïve neurons co-cultured with astrocytes that have previously experienced chronic Aβ1-40 exposure. In this abnormal astrocytic condition, hippocampal neurons exhibit decrements of evoked excitatory post-synaptic currents (EPSCs) and miniature EPSC frequency. Furthermore, size of readily releasable synaptic pools and number of excitatory synapses were also significantly decreased. Contrary to these negative effects, release probability at individual synapses was significantly increased in the same astrocytic condition. Taken together, our data indicate that lower synaptic transmission caused by astrocytes previously, and chronically, exposed to Aβ1-40 is attributable to a small number of synapses with higher release probability.
Response characteristics of hydrogen gas sensor with porous piezoelectric poly(vinylidene fluoride) film Peer-reviewed

Yuji Imai, Daisuke Tadaki, Teng Ma, Yasuo Kimura, Ayumi Hirano-Iwata, Michio Niwano

SENSORS AND ACTUATORS B-CHEMICAL　247　479-489　2017/08
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2017.03.001 　

ISSN：0925-4005

More details Close

Previously, we have proposed a new type of organic hydrogen gas sensor in which a beta-phase poly(vinylidene fluoride) (PVDF) film is coated with thin films of palladium (Pd) on both sides. Volume expansion of the Pd thin film caused by uptake of hydrogen is monitored by a capacitance change of the piezoelectric PVDF thin film. The beta-phase PVDF film was synthesized from alpha-phase PVDF powder by using a wet process that we developed. In this study, we have examined the microscopic structure of the alpha-phase PVDF films and investigated the response characteristics of the sensors: response at hydrogen exposure, detection sensitivity, recovery time and effect of humidity. We find that the PVDF film has the porous structure consisting of micro-scaled grains of PVDF and demonstrates that the response characteristics depend on the structure of the PVDF films. We propose a simple simulation model to get insight into the observed response characteristics. In the model, it is assumed that PVDF micro-grains expand and shrink one by one while exposing to hydrogen and air (or oxygen), respectively. The simulation explains the basic response characteristics of the sensor. (C) 2017 Elsevier B.V. All rights reserved.
Fabrication of resistively-coupled single-electron device using an array of gold nanoparticles Peer-reviewed

T. T, T. Huong, K. Matsumoto, M. Moriya, H. Shimada, Y. Kimura, A. Hirano-Iwata, Y. Mizugaki

Appl. Phys. A　123　557　2017/07/31
Fabrication of Au-nanoparticle-embedded lipid bilayer membranes supported on solid substrates Peer-reviewed

N. Sakaguchi, Y. Kimura, A. Hirano-Iwata, T. Ogino

J. Phys. Chem. B.　121　4474-4481　2017/04/17
Gate‑tuned negative differential resistance observed at room temperature in an array of gold nanoparticles Peer-reviewed

Tran Thi Thu Huong, Kazuhiko Matsumoto, Masataka Moriya, Hiroshi Shimada, Yasuo Kimura, Ayumi Hirano‐Iwata, Yoshinao Mizugaki

Appl. Physics A　123　268　2017/03/22
Charge transport properties in perovskite thin films

Ma Teng, Tadaki Daisuke, Hirano-Iwata Ayumi, Niwano Michio

JSAP Annual Meetings Extended Abstracts　2017.1　2685-2685　2017/03/01
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2017.1.0_2685 　

eISSN：2436-7613
Label-free detection of DNA molecules moving in micro -fluidic channels by infrared absorption spectroscopy Peer-reviewed

Tomoyuki Miyoshi, Ken-ichi Ishibashi, Koichiro Miyamoto, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

SENSORS AND ACTUATORS B-CHEMICAL　238　917-922　2017/02
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2016.07.003 　

ISSN：0925-4005

More details Close

Infrared absorption spectroscopy (IRAS) in a multiple internal reflection (MIR) geometry is integrated with silicon-based micro-fluidic channels to allow detection and separation of DNA molecules in the micro-channels. The micro-channels were fabricated on a Si MIR-prism using the conventional silicon lithographic techniques. In the present method we can probe solution-phase biomolecular species through IR spectral profiles of those biomolecules, allowing us to detect and separate biomolecules without fluorescence labeling. The applicability of this approach is demonstrated with a representative test case: transport of single-stranded DNA molecules (oligonucleotides) in the micro-fluidic channels. (C) 2016 Elsevier B.V. All rights reserved.
Fabrication and Characterization of High-Quality Perovskite Films with Large Crystal Grains Peer-reviewed

Teng Ma, Qiwu Zhang, Daisuke Tadaki, Ayumi Hirano-Iwata, Michio Niwano

Journal of Physical Chemistry Letters　2017/01/27
Stabilization of artificial cell membranes based on nano- and micro-structures

Hirano-Iwata Ayumi, Tadaki Daisuke, Ohori Takeshi, Arata Kohei, Ma Teng, Yamamoto Hideaki, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　37　(0)　297-297　2017
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.37.0_297 　
Fabrication and Characterization of Front-Illuminated Dye-Sensitized Solar Cells with Anodic Titanium Oxide Nanotubes Peer-reviewed

Ryota Kojima, Yasuo Kimura, Teng Ma, Ken-ichi Ishibashi, Daisuke Tadaki, Richard A. Rosenberg, Ayumi Hirano-Iwata, Michio Niwano

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　164　(2)　H78-H84　2017
Publisher: ELECTROCHEMICAL SOC INC
DOI： 10.1149/2.1031702jes 　

ISSN：0013-4651

eISSN：1945-7111

More details Close

We have fabricated front-side illuminated dye-sensitized solar cells (DSSCs) with a thin film of vertically oriented TiO2 nanotubes used as the negative electrode. The TiO2 nanotube film was formed by anodizing a metallic titanium thin film that was deposited on a transparent conductive oxide (TCO) layer with an intermediate, protective TiO2 layer. We characterized the structural and electronic properties of the formed TiO2 nanotube films. Titanium tetrachloride (TiCl4) treatment was applied on the TiO2 nanotube film to improve the performance of the DSSCs. We have investigated effects of TiCl4 treatment on the solar cell parameters of the DSSCs: short-circuit current density (I-SC), open-circuit voltage (V-oc), ideal factor (n), series resistance (R-s) and shunt resistance (R-sh). The parameters have been derived by analyzing measured I-V characteristic of the DSSCs on the basis of the method we have previously proposed. We demonstrate that the performance of the DSSCs is improved by TiCl4 treatment. We discuss the effects of TiCl4 treatment on the performance on the basis of the derived cell parameters. (C) 2016 The Electrochemical Society. All rights reserved.
Fabrication of single-electron devices using dispersed nanoparticles and fitting experimental results to values calculated based on percolation model Peer-reviewed

Masataka Moriya, Tran Thi Thu Huong, Kazuhiko Matsumoto, Hiroshi Shimada, Yasuo Kimura, Ayumi Hirano-Iwata, Yoshinao Mizugaki

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING　122　(8)　2016/08
Publisher: SPRINGER
DOI： 10.1007/s00339-016-0285-3 　

ISSN：0947-8396

eISSN：1432-0630

More details Close

We calculated the connection probability, P-C, between electrodes on the basis of the triangular lattice percolation model for investigating the effect of distance variation between electrodes and the electrode width on fabricated capacitively coupled single-electron transistors. Single-electron devices were fabricated via the dispersion of gold nanoparticles (NPs). The NPs were dispersed via the repeated dropping of an NP solution onto a chip. The experimental results were fitted to the calculated values, and the fitting parameters were compared with the occupation probability, P-O, which was estimated for one drop of the NP solution. On the basis of curves of the drain current versus the drain-source voltage (I-D-V-DS) measured at 77 K, the current was suppressed at approximately 0 V.
Size-dependent regulation of synchronized activity in living neuronal networks Peer-reviewed

Hideaki Yamamoto, Shigeru Kubota, Yudai Chida, Mayu Morita, Satoshi Moriya, Hisanao Akima, Shigeo Sato, Ayumi Hirano-Iwata, Takashi Tanii, Michio Niwano

PHYSICAL REVIEW E　94　(1)　2016/07
Publisher: AMER PHYSICAL SOC
DOI： 10.1103/PhysRevE.94.012407 　

ISSN：2470-0045

eISSN：2470-0053

More details Close

We study the effect of network size on synchronized activity in living neuronal networks. Dissociated cortical neurons form synaptic connections in culture and generate synchronized spontaneous activity within 10 days in vitro. Using micropatterned surfaces to extrinsically control the size of neuronal networks, we show that synchronized activity can emerge in a network as small as 12 cells. Furthermore, a detailed comparison of small (similar to 20 cells), medium (similar to 100 cells), and large (similar to 400 cells) networks reveal that synchronized activity becomes destabilized in the small networks. A computational modeling of neural activity is then employed to explore the underlying mechanism responsible for the size effect. We find that the generation and maintenance of the synchronized activity can be minimally described by: (1) the stochastic firing of each neuron in the network, (2) enhancement in the network activity in a positive feedback loop of excitatory synapses, and (3) Ca-dependent suppression of bursting activity. The model further shows that the decrease in total synaptic input to a neuron that drives the positive feedback amplification of correlated activity is a key factor underlying the destabilization of synchrony in smaller networks. Spontaneous neural activity plays a critical role in cortical information processing, and our work constructively clarifies an aspect of the structural basis behind this.
Unidirectional signal propagation in primary neurons micropatterned at a single-cell resolution Peer-reviewed

H. Yamamoto, R. Matsumura, H. Takaoki, S. Katsurabayashi, A. Hirano-Iwata, M. Niwano

APPLIED PHYSICS LETTERS　109　(4)　2016/07
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4959836 　

ISSN：0003-6951

eISSN：1077-3118

More details Close

The structure and connectivity of cultured neuronal networks can be controlled by using micropatterned surfaces. Here, we demonstrate that the direction of signal propagation can be precisely controlled at a single-cell resolution by growing primary neurons on micropatterns. To achieve this, we first examined the process by which axons develop and how synapses form in micropatterned primary neurons using immunocytochemistry. By aligning asymmetric micropatterns with a marginal gap, it was possible to pattern primary neurons with a directed polarization axis at the single-cell level. We then examined how synapses develop on micropatterned hippocampal neurons. Three types of micropatterns with different numbers of short paths for dendrite growth were compared. A normal development in synapse density was observed when micropatterns with three or more short paths were used. Finally, we performed double patch clamp recordings on micropatterned neurons to confirm that these synapses are indeed functional, and that the neuronal signal is transmitted unidirectionally in the intended orientation. This work provides a practical guideline for patterning single neurons to design functional neuronal networks in vitro with the direction of signal propagation being controlled. Published by AIP Publishing.
微細加工脂質二分子膜チップへのイオンチャネルの包埋

平野愛弓, 吉田美優, 荒木駿, 但木大介, 山本英明, 庭野道夫

信学技報　116　(14)　1-3　2016/04/14

ISSN：0913-5685
安定な人工脂質二分子膜形成のための微細孔を有するシリコンチップの作製

但木大介, 平野愛弓, 石橋健一, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫

信学技報　116　(14)　5-7　2016/04/14
Publisher: None
ISSN：0913-5685
Fabrication and characterization of p(+)-i-p(+) type organic thin film transistors with electrodes of highly doped polymer Peer-reviewed

Daisuke Tadaki, Teng Ma, Jinyu Zhang, Shohei Iino, Ayumi Hirano-Iwata, Yasuo Kimura, Richard A. Rosenberg, Michio Niwano

JOURNAL OF APPLIED PHYSICS　119　(15)　154503-1-154503-8　2016/04
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4946888 　

ISSN：0021-8979

eISSN：1089-7550

More details Close

Organic thin film transistors (OTFTs) have been explored because of their advantageous features such as light-weight, flexible, and large-area. For more practical application of organic electronic devices, it is very important to realize OTFTs that are composed only of organic materials. In this paper, we have fabricated p(+)-i-p(+) type of OTFTs in which an intrinsic (i) regioregular poly (3-hexylthiophene) (P3HT) layer is used as the active layer and highly doped p-type (p(+)) P3HT is used as the source and drain electrodes. The 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F-4-TCNQ) was used as the p-type dopant. A fabricating method of p(+)-i-p(+) OTFTs has been developed by using SiO2 and aluminum films as capping layers for micro-scaled patterning of the p(+)-P3HT electrodes. The characteristics of the OTFTs were examined using the photoelectron spectroscopy and electrical measurements. We demonstrated that the fabricated p(+)-i-p(+) OTFTs work with carrier injection through a built-in potential at p(+)/i interfaces. We found that the p(+)-i-p(+) OTFTs exhibit better FET characteristics than the conventional P3HT-OTFT with metal (Au) electrodes, indicating that the influence of a carrier injection barrier at the interface between the electrode and the active layer was suppressed by replacing the metal electrodes with p(+)-P3HT layers. Published by AIP Publishing.
Secondary growth of perovskite crystal for pinhole-free perovskite layers with large single-crystal grains

Ma Teng, Tadaki Daisuke, Hirano-Iwata Ayumi, Niwano Michio

JSAP Annual Meetings Extended Abstracts　2016.1　2590-2590　2016/03/03
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2016.1.0_2590 　

eISSN：2436-7613
Interaction of plasma-generated water cluster ions with chemically-modified Si surfaces investigated by infrared absorption spectroscopy Peer-reviewed

Ayumi Hirano-Iwata, Ryosuke Matsumura, Teng Ma, Yasuo Kimura, Michio Niwano, Kazuo Nishikawa

AIP ADVANCES　6　(3)　035017　2016/03
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4944902 　

ISSN：2158-3226

More details Close

We have investigated the interaction of water cluster ions generated by discharge plasma, with chemically modified Si surfaces using infrared absorption spectroscopy in the multiple internal reflection geometry. We observe that water cluster ions readily adsorb on SiO2-covered Si surfaces to form water droplets. We demonstrate that positively-and negatively-charged cluster ions adsorb on the SiO2-covered Si surface in different manners, indicating ionic interaction of the water droplets with the negatively-charged SiO2 surface. Water droplets formed on the protein- coated surface rupture the amide bond of the proteins, suggesting the function of protein decomposition of water cluster ions. (c) 2016 Author(s).
Extraction of morphological features of exosomes adsorbed on substrates for host cell identification

Ito Kazuki, Ogawa Yuta, Yokota Keiji, Matsumura Sachiko, Minamisawa Tamiko, Suga Kanako, Shiba Kiyotaka, Kimura Yasuo, Hirano-Iwata Ayumi, Ogino Toshio

Abstract of annual meeting of the Surface Science of Japan　36　150-150　2016
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.36.0_150 　
Development of an artificial cell membrane array based on silicon microfabrication

Araki Shun, Hirano-Iwata Ayumi, Miyata Ryusuke, Tadaki Daisuke, Ishibashi Kenichi, Yamamoto Hideaki, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　36　146-146　2016
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.36.0_146 　
Effects of interfacial chemical states on the performance of perovskite solar cells Peer-reviewed

Teng Ma, Daisuke Tadaki, Masao Sakuraba, Shigeo Sato, Ayumi Hirano-Iwata, Michio Niwano

Journal of Materials Chemistry A　4　(12)　4392-4397　2016
Publisher: Royal Society of Chemistry
DOI： 10.1039/c5ta08098c 　

ISSN：2050-7496 2050-7488

eISSN：2050-7496

More details Close

We showed that the widely used solvent molecule, N,N-dimethyl-formamide (DMF), readily adsorbs on the surface of TiO2 electrodes of perovskite solar cells (PSCs), and that the adsorbed DMF molecules remain intact on the TiO2 surface even after long-term annealing of the perovskite layer, resulting in an increase in the contact resistance of the PSCs. We found that the absorption of DMF is significantly suppressed by modifying the TiO2 electrode surface with a fullerene derivative, [6,6]-phenyl-C61-butyric acid (PCBA). We also suggested that the high electron affinity of PCBA enhances the charge transportation at the perovskite/TiO2 interface and reduces the contact resistance.
An electrically resistive sheet of glial cells for amplifying signals of neuronal extracellular recordings Peer-reviewed

R. Matsumura, H. Yamamoto, M. Niwano, A. Hirano-Iwata

APPLIED PHYSICS LETTERS　108　(2)　2016/01
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4939629 　

ISSN：0003-6951

eISSN：1077-3118

More details Close

Electrical signals of neuronal cells can be recorded non-invasively and with a high degree of temporal resolution using multielectrode arrays (MEAs). However, signals that are recorded with these devices are small, usually 0.01%-0.1% of intracellular recordings. Here, we show that the amplitude of neuronal signals recorded with MEA devices can be amplified by covering neuronal networks with an electrically resistive sheet. The resistive sheet used in this study is a monolayer of glial cells, supportive cells in the brain. The glial cells were grown on a collagen-gel film that is permeable to oxygen and other nutrients. The impedance of the glial sheet was measured by electrochemical impedance spectroscopy, and equivalent circuit simulations were performed to theoretically investigate the effect of covering the neurons with such a resistive sheet. Finally, the effect of the resistive glial sheet was confirmed experimentally, showing a 6-fold increase in neuronal signals. This technique feasibly amplifies signals of MEA recordings. (C) 2016 AIP Publishing LLC.
Photopatterning Proteins and Cells in Aqueous Environment Using TiO2 Photocatalysis Peer-reviewed

Hideaki Yamamoto, Takanori Demura, Kohei Sekine, Sho Kono, Michio Niwano, Ayumi Hirano-Iwata, Takashi Tanii

JOVE-JOURNAL OF VISUALIZED EXPERIMENTS　(104)　2015/10
Publisher: JOURNAL OF VISUALIZED EXPERIMENTS
DOI： 10.3791/53045 　

ISSN：1940-087X

More details Close

Organic contaminants adsorbed on the surface of titanium dioxide (TiO2) can be decomposed by photocatalysis under ultraviolet (UV) light. Here we describe a novel protocol employing the TiO2 photocatalysis to locally alter cell affinity of the substrate surface. For this experiment, a thin TiO2 film was sputter-coated on a glass coverslip, and the TiO2 surface was subsequently modified with an organosilane monolayer derived from octadecyltrichlorosilane (OTS), which inhibits cell adhesion. The sample was immersed in a cell culture medium, and focused UV light was irradiated to an octagonal region. When a neuronal cell line PC12 cells were plated on the sample, cells adhered only on the UV-irradiated area. We further show that this surface modification can also be performed in situ, i.e., even when cells are growing on the substrate. Proper modification of the surface required an extracellular matrix protein collagen to be present in the medium at the time of UV irradiation. The technique presented here can potentially be employed in patterning multiple cell types for constructing coculture systems or to arbitrarily manipulate cells under culture.
Molecular doping of regioregular poly(3-hexylthiophene) layers by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane investigated by infrared spectroscopy and electrical measurements Peer-reviewed

Daisuke Tadaki, Teng Ma, Jinyu Zhang, Shohei Iino, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

JAPANESE JOURNAL OF APPLIED PHYSICS　54　(9)　2015/09
Publisher: IOP PUBLISHING LTD
DOI： 10.7567/JJAP.54.091602 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

Molecular doping is a charge-transfer process intended to improve the performance of organic electronic devices such as organic transistors. We have investigated molecular doping of regioregular poly(3-hexylthiophene) (P3HT) layers by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F-4-TCNQ) using infrared absorption spectroscopy in the multiple internal reflection geometry (MIR-IRAS) and conductivity measurements. IRAS data confirm that F-4-TCNQ acts as an effective p-type dopant for P3HT; highly doped P3HT displayed an intense, broad absorption band due to polaron ("polaron band") and a high carrier (hole) density which are indicative of the charge transfer between F-4-TCNQ and P3HT. We demonstrate that the charge (hole) transferred from the dopant molecule is distributed along the P3HT polymer chain and spreads over at least 10 thiophene monomer units on the chain. From a comparison of the measured conductivity of F-4-TCNQ-doped P3HT layers with the carrier density, we show that the carrier mobility is proportional to the concentration of carriers (holes), which suggests that F-4-TCNQ doping induces the conformational change of P3HT polymer chains to enhance the mobility of holes in the films of the doped P3HTs. (C) 2015 The Japan Society of Applied Physics
Micro- and Nano-Technologies for Lipid Bilayer-Based Ion-Channel Functional Assays Peer-reviewed

Ayumi Hirano-Iwata, Yutaka Ishinari, Hideaki Yamamoto, Michio Niwano

CHEMISTRY-AN ASIAN JOURNAL　10　(6)　1266-1274　2015/06
Publisher: WILEY-V C H VERLAG GMBH
DOI： 10.1002/asia.201403391 　

ISSN：1861-4728

eISSN：1861-471X

More details Close

Ion channel proteins provide gated pores that allow ions to passively flow across cell membranes. Owing to their crucial roles in regulating transmembrane ion flow, ion channel proteins have attracted the attention of pharmaceutical investigators as drug targets for use in the studies of both therapeutics and side effects. In this review, we discuss the current technologies that are used in the formation of ion channel-integrated bilayer lipid membranes (BLMs) in microfabricated devices as a potential platform for next-generation drug screening systems. Advances in BLM fabrication methodology have allowed the preparation of BLMs in sophisticated formats, such as microfluidic, automated, and/or array systems, which can be combined with channel current recordings. A much more critical step is the integration of the target channels into BLMs. Current technologies for the functional reconstitution of ion channel proteins are presented and discussed. Finally, the remaining issues of the BLM-based methods for recording ion channel activities and their potential applications as drug screening systems are discussed.
In-situ observation of reactions of water cluster ions with polypeptides by infrared absorption spectroscopy

Yoshida Mao, Ma Teng, Yamamoto Hideaki, Hirano Ayumi, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　35　406-406　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_406 　
Formation of artificial cell membranes based on microfabricated silicon substrates

Araki Shun, Hirano Ayumi, Yamamoto Hideaki, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　35　172-172　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_172 　
Morphological observation of lipid bilayers embedding Au nanoparticles

Sakaguchi Naotoshi, Nakayama Tomoaki, Kimura Ryosuke, Kimura Yasuo, Hirano-Iwata Ayumi, Ogino Toshio

Abstract of annual meeting of the Surface Science of Japan　35　175-175　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_175 　
Characterization of size distribution and adsorption types of exosomes

Ogawa Yuta, Itou Kazuki, Matumura Yukiko, Suga Kanako, Shiba Kiyotaka, Kimura Yasuo, Hirano Ayumi, Ogino Toshio

Abstract of annual meeting of the Surface Science of Japan　35　408-408　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_408 　
Generation of nanobubbles by porous alumina thin films

Yamada Natsuki, Saito Hideyuki, Ma Teng, Hirano Ayumi, Yamamoto Hideaki, Ishibashi Ken-ichi, Miyazawa Makoto, Sakamoto Hitoshi, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　35　281-281　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_281 　
Surface micromodification techniques for engineering cultured neurons and neuronal networks

Yamamoto Hideaki, Hirano-Iwata Ayumi, Tanii Takashi, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　35　21-21　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_21 　
Annealing-induced chemical and structural changes in tri-iodide and mixed-halide organometal perovskite layers Peer-reviewed

Teng Ma, Matteo Cagnoni, Daisuke Tadaki, Ayumi Hirano-Iwata, Michio Niwano

JOURNAL OF MATERIALS CHEMISTRY A　3　(27)　14195-14201　2015
Publisher: ROYAL SOC CHEMISTRY
DOI： 10.1039/c5ta03039k 　

ISSN：2050-7488

eISSN：2050-7496

More details Close

The annealing process is crucial for obtaining high-quality perovskite layers used in highly efficient planar perovskite solar cells. In this study, we have investigated the annealing-induced chemical and structural changes of tri-iodide (TI) and mixed-halide (MH) organometal perovskite layers using infrared absorption spectroscopy, scanning electron microscopy and X-ray diffraction measurements. For TI layers, the solvent molecules, dimethylformamide (DMF), remained in the form of the PbI2/DMF compound after drying at room temperature. During annealing, the DMF evaporated to form PbI2 crystals. When the MH perovskite film was annealed, both CH3NH3PbCl3 and CH3NH3PbI3 crystals were initially formed from an amorphous phase. With further annealing, the CH3NH3PbI3 crystals gradually grew through the incorporation of source materials supplied from the CH3NH3PbCl3 crystals and the amorphous phase and the slow evaporation of methylammonium (MA) and chloride ions. The resultant MH perovskite layer after annealing was mainly composed of large CH3NH3PbI3 grains with a trace of chloride ions. We suggest that the difference in composition and structure leads to different charge transport properties of the TI and MH perovskite layers.
Real-time monitoring of extracellular l-glutamate levels released by high-frequency stimulation at region CA1 of hippocampal slices with a glass capillary-based l-glutamate sensor Peer-reviewed

Yuki Ikegami, Shizuko Hozumi, Atsushi Shoji, Ayumi Hirano-Iwata, Tim Bliss, Masao Sugawara

Sensing and Bio-Sensing Research　2　31-37　2014/12/01
Publisher: Elsevier
DOI： 10.1016/j.sbsr.2014.10.006 　

ISSN：2214-1804

eISSN：2214-1804

More details Close

Real-time monitoring of l-glutamate released by high-frequency stimulation in region CA1 of mouse hippocampal slices was performed with a glass capillary-based sensor, in combination with the recoding of excitatory postsynaptic potentials (fEPSPs). A method for extracting l-glutamate currents from the recorded ones was described and applied for determining the level of extracellular l-glutamate released by 100. Hz stimulation. Recording of an l-glutamate current with a current sampling interval of 1. Hz was found to be useful for acquiring a Faradaic current that reflects l-glutamate level released by the high-frequency stimulation of 7. trains, each 20. stimuli at 100. Hz and inter-train interval of 3. s. The l-glutamate level was obtained as 15. ±. 6. μM (n=8) for the persistent enhancement of fEPSPs, i.e., the induction of long-term potentiation (LTP), and 3. ±. 1. μM (n=5) for the case of no LTP induction. Based on these observations, the level of the extracellular l-glutamate was shown to play a crucial role in the induction of LTP.
Interference between field excitatory postsynaptic potentials and simultaneously recorded chronoamperometric L-glutamate currents in mouse hippocampal slices Peer-reviewed

Ayumi Hirano-Iwata, Ryosuke Matsumura, Ryuta Tezuka, Michio Niwano, Tim V. P. Bliss, Masao Sugawara

ELECTROCHEMISTRY COMMUNICATIONS　45　1-4　2014/08
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.elecom.2014.04.016 　

ISSN：1388-2481

eISSN：1873-1902

More details Close

Here we report on an unexpected interaction between field excitatory postsynaptic potentials (fEPSPs) and simultaneously recorded chronoamperometric L-glutamate currents based on time-resolved (200 Hz) amperometry in mouse hippocampal slices. It was found that electric stimuli and evoked fEPSPs induced an artifact on amperometric currents due to an unintentionally formed junction between the circuits of the amperometric and fEPSP measurements. The origin of the artifact was investigated using circuit simulation. To extract a faradaic signal from the observed currents, we sampled currents when the artifact decayed, i.e., 450 ms after the stimulation. The reliability of the extracted signal was examined through the manipulation of L-glutamate release probability. (C) 2014 Elsevier B.V. All rights reserved.
微細加工シリコン基板とイオンチャネルの融合

石成裕, 平野愛弓, 山本英明, 木村康男, 庭野道夫

表面科学学術講演会要旨集　34　60-60　2014
Publisher: 公益社団法人日本表面科学会
DOI： 10.14886/sssj2008.34.0_60 　

More details Close

膜タンパク質の一つであるイオンチャネルは高感度な分子認識機能を有し，創薬における主ターゲットになっている。我々はイオンチャネルを人工脂質二分子膜に包埋した再構成系に基づく薬物スクリーニングチップの開発を目指しており，半導体微細加工との融合による安定な脂質二分子膜の構築について報告してきた。今回は，この安定化脂質二分子膜中への幾つかのイオンチャネル包埋について検討したので，ここに報告する。
3P221 Recording Ion-Channel Activities Based on Microfabricated Silicon Chips(Biological & Artificial membrane: Excitation & Channels,Poster,The 52th Annual Meeting of the Biophysical Society of Japan(BSJ2014))

Yutaka Ishinari, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

Seibutsu Butsuri　54　(1)　S285　2014
Publisher: The Biophysical Society of Japan General Incorporated Association
DOI： 10.2142/biophys.54.S285_5 　
1SDA-02 Manipulating neurons and neuronal networks with micropatterned surfaces(1SDA Measurement and control of neurodynamics,Symposium,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014))

Yamamoto Hideaki, Tanii Takashi, Niwano Michio, Hirano-Iwata Ayumi

Seibutsu Butsuri　54　(1)　S118　2014
Publisher: The Biophysical Society of Japan General Incorporated Association
DOI： 10.2142/biophys.54.S118_1 　
Label-free and real time monitoring of adipocyte differentiation by surface infrared spectroscopy Peer-reviewed

Yuki Aonuma, Yasuhiko Kondo, Ayumi Hirano-Iwata, Atena Nishikawa, Yasuo Shinohara, Hiroo Iwata, Yasuo Kimura, Michio Niwano

SENSORS AND ACTUATORS B-CHEMICAL　176　1176-1182　2013/01
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2012.10.030 　

ISSN：0925-4005

More details Close

We have investigated in situ real-time monitoring of cell differentiation to adipocytes by using infrared absorption spectroscopy with the multiple internal reflection (MIR-IRAS) geometry. Preadipocyte 3T3-L1 cells were cultured on a silicon prism and their adipogenesis was monitored with MIR-IRAS for seven days. Differentiated cells showed a C=O stretching band of triacylglycerides, together with the protein amide I and amide II bands. The C=O stretching band appeared before optical microscopic confirmation of fat droplet formation, a typical morphological marker for adipocytes, demonstrating that MIR-IRAS is particularly useful for non-destructive monitoring of early adipogenesis. An effect of genistein, an antiadipogenic agent, was also investigated based on the peak intensity of the C=O stretching and amide bands. Thus, MIR-IRAS has a potential to evaluate antiadipogenic agents in terms of their effects on fat and protein synthesis during adipogenesis. (C) 2012 Elsevier B. V. All rights reserved.
Lipid bilayer array for simultaneous recording of ion channel activities Peer-reviewed

Ayumi Hirano-Iwata, Tomohiro Nasu, Azusa Oshima, Yasuo Kimura, Michio Niwano

APPLIED PHYSICS LETTERS　101　(2)　023702-1-023702-3　2012/07
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4736263 　

ISSN：0003-6951

More details Close

This paper describes an array of stable and reduced-solvent bilayer lipid membranes (BLMs) formed in microfabricated silicon chips. BLMs were first vertically formed simultaneously and then turned 90 degrees in order to realize a horizontal BLM array. Since the present BLMs are mechanically stable and robust, the BLMs survive this relatively tough process. Typically, a similar to 60% yield in simultaneous BLM formation over 9 sites was obtained. Parallel recordings of gramicidin channel activities from different BLMs were demonstrated. The present system has great potential as a platform of BLM-based high throughput drug screening for ion channel proteins. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4736263]
Mechanically stable lipid bilayers in Teflon-coated silicon chips for single-channel recordings Peer-reviewed

Azusa Oshima, Ayumi Hirano-Iwata, Tomohiro Nasu, Yasuo Kimura, Michio Niwano

Micro and Nanosystems　4　(1)　2-7　2012/06

DOI： 10.2174/1876402911204010002 　

ISSN：1876-4029 1876-4037

More details Close

We demonstrate the microfabrication of a low-noise silicon (Si) chip as a platform for suspending mechanically stable bilayer lipid membranes (BLMs). Microapertures with smoothly tapered edges were formed by isotropic etching in a silicon nitride layer deposited on a Si substrate. The surface of the Si chip was coated with insulator layers of Teflon and SiO2. The insulator coating worked to reduce the total capacitance, leading to noise reduction (1-2 pA in peak-to-peak after low-pass filtering at 1 kHz) and elimination of current transients (&lt 0.5 ms). Since the tapered edges were necessary to maintain mechanically stable BLMs, the entire chip except for the aperture was coated with the insulators. Owing to this process, the BLMs formed in the Si chips still showed high mechanical stability after coating with the insulator layers. The membranes withstood high applied voltage (±1 V) and mechanical shocks during solution exchanges. The mechanically stable BLMs having electric properties suitable for recording activities of biological channels will open up a variety of applications including high-throughput analysis of ion-channel proteins. © 2012 Bentham Science Publishers.
A lipid bilayer array for simultaneous recording of ion-channel currents

Mozumi Hideki, Nasu Tomohiro, Hirano-Iwata Ayumi, Oshima Azusa, Kimura Yasuo, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　32　203-203　2012
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.32.0_203 　
In situ modification of lipid-loaded MCM-41 channels with bovine serum albumin at a planar lipid bilayer for biosensing Peer-reviewed

Keiichiro Nozawa, Azusa Oshima, Tomohiro Nasu, Atsushi Shoji, Ayumi Hirano-Iwata, Michio Niwano, Masao Sugawara

SENSORS AND ACTUATORS B-CHEMICAL　160　(1)　139-144　2011/12
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2011.07.024 　

ISSN：0925-4005

More details Close

An in situ method for modifying a receptor site on mesoporous silica MCM-41 channels in planar lipid bilayers is described, in which bovine serum albumin (BSA) is covalently linked to the MCM-41 channels via head groups of lipids loaded in the nanopores. Prior to receptor modification, lipid-loaded MCM-41 channels were incorporated with lipid bilayers formed at an aperture of a Teflon film. The in situ coupling of BSA to lipid-loaded MCM-41 channels at the lipid bilayer interface was achieved by the sulfhydryl coupling method. The lipid bilayers containing BSA-modified MCM-41 exhibited channel-like currents, which were augmented in a concentration-dependent manner by the addition of anti-BSA at fM level. The in situ modification of lipid-loaded MCM-41 channels with BSA by the amine coupling technique was also investigated. The potential of the present approach for the development of channel-type biosensors is discussed in terms of modifying bilayer interfaces with bioreceptors. (C) 2011 Elsevier B.V. All rights reserved.
Real-time monitoring of mitochondrial adenosine 5 '-triphosphate synthesis and hydrolysis by surface infrared spectroscopy Peer-reviewed

Ryo-Taro Yamaguchi, Ayumi Hirano-Iwata, Yuki Aonuma, Yuya Yoshimura, Yasuo Shinohara, Yasuo Kimura, Michio Niwano

APPLIED PHYSICS LETTERS　98　(13)　133703-1-133703-3　2011/03
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.3571551 　

ISSN：0003-6951

eISSN：1077-3118

More details Close

We have developed a method for in situ real-time monitoring of adenosine 5'-triphosphate (ATP) synthesis in mitochondria using infrared absorption spectroscopy with the multiple internal reflection geometry. Spectral changes corresponding to ATP synthesis and hydrolysis were monitored under oxygenation and constant stirring condition. It was demonstrated that the reversible process of ATP synthesis in mitochondria can be monitored by analyzing stretching modes of alpha- and beta-PO2- in adenine nucleotides. Our method has potential to evaluate mitochondrial toxicity in terms of mitochondrial activities of ATP synthesis and hydrolysis. (C) 2011 American Institute of Physics. [doi:10.1063/1.3571551]
Simultaneous monitoring of excitatory postsynaptic potentials and extracellular L-glutamate in mouse hippocampal slices Peer-reviewed

Shizuko Hozumi, Kana Ikezawa, Atushi Shoji, Ayumi Hirano-Iwata, Tim Bliss, Masao Sugawara

BIOSENSORS & BIOELECTRONICS　26　(6)　2975-2980　2011/02
Publisher: ELSEVIER ADVANCED TECHNOLOGY
DOI： 10.1016/j.bios.2010.11.052 　

ISSN：0956-5663

More details Close

Simultaneous monitoring of amperometric currents at a glass capillary sensor based on recombinant GluOx and field excitatory postsynaptic potentials (fEPSPs) were performed in region CA1 of mouse hippocampal slices. A transient increase in the glutamate current relative to the basal one at control stimulation (0.052 Hz) was evoked by stimulation at 2 Hz for 2 min. The magnitude of the glutamate current was dependent on the intensity (current) of a 2 Hz stimulus and reflected the slope of the fEPSP. The in situ calibration of the L-glutamate sensor revealed that the extracellular concentration of L-glutamate released by 2 Hz stimulation before tetanus is in the range from 0.8 to 2.2 mu M and it is enhanced after tetanic stimulation. The L-glutamate level at a test stimulus (0.052 Hz) was estimated to be 32 nM. The recombinant GluOx-based sensor exhibited weak responses to glutamine above 300 mu M and L-aspartic acid above 200 mu M. The potential use of a glass capillary sensor in combination with fEPSP measurements for electrophysiological study is discussed. (C) 2010 Elsevier B.V. All rights reserved.
Improved stability of free-standing lipid bilayers based on nanoporous alumina films Peer-reviewed

Ayumi Hirano-Iwata, Tasuku Taira, Azusa Oshima, Yasuo Kimura, Michio Niwano

APPLIED PHYSICS LETTERS　96　(21)　213706　2010/05
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.3441298 　

ISSN：0003-6951

More details Close

In this study, we propose a method for improving the stability of free-standing bilayer lipid membranes (BLMs) by preparing BLMs across nanoporous alumina films. The use of porous alumina reduced individual membrane size to improve the BLM stability. The BLMs were stable under an applied voltage of +/- 1 V. The lifetime of the BLMs was 16-30 h with and without incorporated gramicidin channels. Electric properties of the BLMs as a platform for channel-current recordings are also discussed. Since the total area of the BLMs is still large to facilitate protein incorporation, our approach is useful for designing highly sensitive biosensors based on channel proteins. (C) 2010 American Institute of Physics. [doi:10.1063/1.3441298]
Self-formation of bilayer lipid membranes on agarose-coated silicon surfaces studied by simultaneous electrophysiological and surface infrared spectroscopic measurements Peer-reviewed

Ayumi Hirano-Iwata, Azusa Oshima, Kota Onodera, Kouji Aoto, Tasuku Taira, Ryo-taro Yamaguchi, Yasuo Kimura, Michio Niwano

APPLIED PHYSICS LETTERS　94　(24)　243906-1-243906-3　2009/06
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.3140206 　

ISSN：0003-6951

More details Close

Self-formation process of bilayer lipid membranes (BLMs) cushioned on agarose-coated Si surfaces was in situ monitored by simultaneous electrophysiological and infrared absorption spectroscopic (IRAS) measurements using IRAS with the multiple internal reflection geometry. IRAS signals corresponding to self-thinning of lipid solution to form BLMs were demonstrated. It was found that the appearance of IRAS bands due to C=O modes of phosphstidylcholine is related to formation of BLMs with a gigaohm seal. The functionality of the present BLM system was also demonstrated by incorporating gramicidin into the BLMs and recording its channel activities.
In situ Surface Infrared Study of DNA Hybridization on Au Island Films Evaporated on Silicon Surfaces Peer-reviewed

Kohki Tanaka, Ayumi Hirano-Iwata, Ko-ichiro Miyamoto, Yasuo Kimura, Michio Niwano

JAPANESE JOURNAL OF APPLIED PHYSICS　48　(4)　04C186-1-04C186-4　2009/04
Publisher: JAPAN SOCIETY APPLIED PHYSICS
DOI： 10.1143/JJAP.48.04C186 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

Here we propose a label-free detection of DNA hybridization on Au nanoisland films deposited on Si surfaces by infrared absorption spectroscopy in the geometry of multiple internal reflection (MIR-IRAS). Au nanoisland films were prepared on Si surfaces by evaporation. DNA immobilization via Au-thiol chemistry and subsequent DNA hybridization was monitored with MIR-IRAS. Interaction with complementary DNA produced an IRAS peak at similar to 1686 cm(-1) where the C=O stretching vibration modes of nucleobases appear. On the other hand, addition of non-complementary DNA induced no significant spectral changes in the same region. Sensitive detection of 40 nM DNA was achieved owing to the MIR geometry combined with Au nanoisland films deposited on Si which provides low-background absorption around the C=O stretching vibration region. Comparison between experimental results and theoretical prediction, obtained using the ab initio calculation, was also examined. (C) 2009 The Japan Society of Applied Physics
Visualizing L-glutamate fluxes in acute hippocampal slices with glutamate oxidase-immobilized coverslips Peer-reviewed

Wataru Okumura, Nobukatsu Moridera, Ena Kanazawa, Atushi Shoji, Ayumi Hirano-Iwata, Masao Sugawara

ANALYTICAL BIOCHEMISTRY　385　(2)　326-333　2009/02
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI： 10.1016/j.ab.2008.10.047 　

ISSN：0003-2697

More details Close

We used a glutamate oxidase (GluOx)-immobilized glass coverslip for reducing diffusional blur and improving the temporal resolution of visualizing L-glutamate fluxes in acute brain slices. The immobilization of GluOx on an avidin modified glass coverslips was achieved by optimized the amine coupling method. The GluOx coverslip was applied to the imaging of L-glutamate fluxes in acute hippocampal slices under hypoxia and KCl stimulation. A slice from mouse brain was loaded with horseradish peroxidase (HRP) and substrate DA-64, and placed on the GluOx coverslip for stimulation. The regional distribution of hypoxia-induced L-glutamate fluxes was analyzed. The maximum flux at 3 min after the onset of hypoxia increased in the order CA1 > CA3 > DG. The time-courses of the L-glutamate fluxes at CA1 and DG were biphasic, while that at CA3 decreased monotonously. The KCl-stimulated release Of L-glutamate in the presence of the DL-TBOA uptake inhibitor was imaged. While no noticeable change was observed in the absence Of DL-TBOA, L-glutamate fluxes in the presence of the inhibitor increased in the order CA1 > CA3 > DG, reflecting the effect of uptake processes. The present approach suppressed diffusional blur of the glutamate signal and improved the temporal resolution as compared with the BSA-HRP membrane method described earlier. (C) 2008 Elsevier Inc. All rights reserved.
In situ real-time monitoring of apoptosis on leukemia cells by surface infrared spectroscopy Peer-reviewed

Ryo-taro Yamaguchi, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano, Ko-ichiro Miyamoto, Hiroko Isoda, Hitoshi Miyazaki

JOURNAL OF APPLIED PHYSICS　105　(2)　024701-1-024701-7　2009/01
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.3068203 　

ISSN：0021-8979

eISSN：1089-7550

More details Close

We have investigated in situ real-time monitoring of apoptosis on human promyelocytic leukemia (HL-60) cells using infrared absorption spectroscopy with the multiple internal reflection (MIR-IRAS) geometry. Actinomycin D (Act D)-induced apoptosis on HL-60 cells was monitored for 24 h. Apoptotic cells showed two strong peaks around the protein amide I and amide II bands probably due to the leakage of cytoplasmic proteins, while growing viable cells showed a peak corresponding to the secretion of metabolites and two downward peaks corresponding to uptake of nutrients from culture media. In addition, IR absorption peak intensity of the amide I and amide II bands was proportional to the extracellular concentration of lactate dehydrogenase, a marker protein for cell damage. These results demonstrate that our MIR-IRAS method is useful for discrimination of apoptotic cells from viable ones and cell apoptotic processes can be monitored in situ by analyzing the amide I and amide II peak intensity.
Peptide Immobilization on GaAs Surfaces and the Application to Label-Free Detection of Antigen-Antibody Interactions Using Multiple Internal Reflection Infrared Spectroscopy Peer-reviewed

Ayumi Hirano, Kota Onodera, Ko-ichiro Miyamoto, Yasuo Kimura, Masatoshi Kataoka, Yasuo Shinohara, Michio Niwano

SENSOR LETTERS　6　(4)　613-617　2008/08
Publisher: AMER SCIENTIFIC PUBLISHERS
DOI： 10.1166/sl.2008.441 　

ISSN：1546-198X

eISSN：1546-1971

More details Close

In this study, we have investigated in-situ the process of antigen immobilization and subsequent antigen-anti body interaction on solid surfaces by using infrared absorption spectroscopy in the multiple internal reflection (MIR-IRAS) geometry. Three kinds of MIR substrates, Si, GaAs and SiO2-deposited GaAs, were investigated in terms of transparency to the IR light and immobilization performance of antigen peptides, which was evaluated by using MIR-IRAS and enhanced chemiluminescence (ECL) assay. The SiO2-deposited GaAs prism provides the highest peptide immobilization efficiency that is compatible with MIR-IRAS measurements in the mid-infrared region. By using Pluronic F-127 as a blocking agent to inhibit nonspecific protein binding to the surfaces, we observed an antiserum-induced increase in the peak intensity corresponding to the amide I and amide II bands, which was selective for the antigen-anti body interaction. The present results show that MIR-IRAS is a promising tool not only for the characterization of the peptide-immobilized surface but also for the label-free detection of antigen-anti body interactions on solid surfaces.
In situ study of DNA attachment and hybridization at silicon surfaces by infrared absorption spectroscopy Peer-reviewed

Ken-Ichi Ishibashi, Kohki Tanaka, Ayumi Hirano-Iwata, Ko-Ichiro Miyamoto, Yasuo Kimura, Michio Niwano

Japanese Journal of Applied Physics　47　(4)　3204-3208　2008/04/25

DOI： 10.1143/JJAP.47.3204 　

ISSN：0021-4922 1347-4065

More details Close

In this study, we have investigated in situ the process of DNA immobilization and the subsequent hybridization on Si surfaces by using infrared (IR) absorption spectroscopy in the geometry of multiple internal reflection (MIR-IRAS). We use 3-aminopropyl-triethoxysilane (APTES) to functionalize Si surfaces with the amine group for DNA attachment. MIR-IRAS data, together with ab initio calculations, demonstrate that the amine-terminated surfaces are covalently coupled to thiolmodified oligonucleotides using a crosslinker of sulfo-succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SSMCC). Hybridization experiments reveal that MIR-IRAS enables us to detect DNA hybridization through IR spectral changes in the frequency region around 1685 cm-1 where the vibrational modes of the bases appear. The present results show that MIR-IRAS is a promising tool for the label-free detection of DNA hybridization as well as the in situ (in vitro) characterization of the conformation changes of DNA molecules immobilized on Si surfaces. © 2008 The Japan Society of Applied Physics.
3P-237 Components of NMDA-induced Ca^<2+> signal in mouse hippocampal slices and acute effects of corticosterone on each component(The 46th Annual Meeting of the Biophysical Society of Japan)

Suzuki Akiyoshi, Osanai Hiromi, Komatsuzaki Yoshimasa, Hirano-Iwata Ayumi, Kawato Suguru, Saito Minoru

Seibutsu Butsuri　48　S164　2008
Publisher: The Biophysical Society of Japan General Incorporated Association
DOI： 10.2142/biophys.48.S164_2
Components of NMDA-Induced Ca2+ Signal in Mouse Hippocampal Slices and Acute Effects of Corticosterone on Each Component. Peer-reviewed

Hiromi Osanai, Akiyoshi Suzuki, Yoshimasa Komatsuzaki, Ayumi Hirano-Iwata, Suguru Kawato, Minoru Saito

Bioimages　16　31-37　2008
Publisher: Bioimaging Society
DOI： 10.11169/bioimages.16.31 　

More details Close

N-methyl-D-aspartate (NMDA) stimulation is usually used to investigate a series of neuronal mechanisms involved in NMDA receptor-mediated Ca2+ signal. We here examined by using Ca2+ imaging technique whether the NMDA-induced Ca2+ signal is due to the exclusive activation of NMDA receptors or activation of voltage-dependent calcium channels (VDCCs) together with NMDA receptors in mouse hippocampal slices. In order to isolate each component of the Ca2+ signal, we used sodium channel antagonist tetrodotoxin (TTX), which prevents dendritic spikes and the following activation of VDCCs, and L-type VDCC antagonist nicardipine. The results showed that in the CA1 region, almost a half of the NMDA-induced Ca2+ signal was the TTX-sensitive component involved in indirect Ca2+ influx via VDCCs, while the other half was the TTX-insensitive component involved in direct Ca2+ influx via NMDA receptors. In addition, the TTX-sensitive component should be almost via L-type VDCCs. We further examined the effects of corticosterone (CORT), which is a principal glucocorticoid synthesized in the rodent adrenal cortex and secreted in response to stress, on each component. It has been reported that CORT acutely (nongenomically) suppress the NMDA-induced Ca2+ signal in the CA1 region. The present results, however, led us to a new finding that CORT enhanced the TTX-insensitive component and the suppressive effect of CORT reported so far should be attributed to the effect on the TTX-sensitive component.
In situ observation of a cell adhesion and metabolism using surface infrared spectroscopy Peer-reviewed

Ko-ichiro Miyamoto, Parida Yamada, Ryo-Taro Yamaguchi, Takami Muto, Ayumi Hirano, Yasuo Kimura, Michio Niwano, Hiroko Isoda

CYTOTECHNOLOGY　55　(2-3)　143-149　2007/12
Publisher: SPRINGER
DOI： 10.1007/s10616-007-9111-2 　

ISSN：0920-9069

More details Close

In this study, we report on an in situ monitoring system of living cultured cells using infrared absorption spectroscopy in the geometry of multiple internal reflections (MIR-IRAS). In order to observe living cultured cells, the temperature in the sample chamber of a FT-IR spectrometer was maintained at 37 degrees C and a humidified gas mixture containing 5% CO2 was introduced into the sample chamber. Human breast cell line MCF-7 cultured on Si MIR prisms were placed in the sample chamber and infrared spectra of MCF-7 cells were collected for 5 h. It was found that the adhesion and metabolism of MCF-7 cells could be monitored by the absorption intensity of amide-II protein band (1,545 cm(-1)) and also by the absorption intensities of CH (x) bands (2,700-3,100 cm(-1) stop). These results suggest that our system is useful for a nondestructive and non-label monitoring of cell viability. Our method based on infrared absorption spectroscopy has a potential for bioscreening application.
Real-time monitoring of cell death by surface infrared spectroscopy Peer-reviewed

Ryo-taro Yamaguchi, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano, Ko-ichiro Miyamoto, Hiroko Isoda, Hitoshi Miyazaki

APPLIED PHYSICS LETTERS　91　(20)　203902　2007/11
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.2813013 　

ISSN：0003-6951

eISSN：1077-3118

More details Close

We have developed a method for real-time monitoring of the cell responses to cytotoxicants using Fourier transform infrared spectroscopy with the multiple internal reflection (MIR-FTIR) geometry. To prevent cell damages induced by measurement environments, we have constructed specialized chambers, in which temperature was maintained at (37 +/- 0.5) degrees C and humidified air containing 5% CO2 was supplied. We monitored cell death induced by cytotoxic surfactant Tween20 using MIR-FTIR spectroscopy. It was found that cell death can be monitored by the absorption intensity of amide II band. This result suggests that our method has a potential to be applied for real-time cytotoxicity assay. (c) 2007 American Institute of Physics.
Label-free detection of protein-protein interactions at the GaAs/Water interface through surface infrared spectroscopy: Discrimination between specific and nonspecific interactions by using secondary structure analysis Peer-reviewed

Kota Onodera, Ayumi Hirano-Iwata, Ko-Ichiro Miyamoto, Yasuo Kimura, Masatoshi Kataoka, Yasuo Shinohara, Michio Niwano

LANGMUIR　23　(24)　12287-12292　2007/11
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/la7022192 　

ISSN：0743-7463

More details Close

Here, we propose a label-free detection of protein-protein interactions that enables simultaneous qualitative analysis of target proteins by using Fourier transform infrared (FTIR) absorption spectroscopy in multiple internal reflection geometry (MIR-FTIR). Using this method, the target proteins were detected based on the peak height of the amide I and amide II bands, while discrimination of specific and nonspecific signals is made based on the secondary structure of the analytes, which is determined through second-derivative analysis of the amide I band. As a model system, an antigen peptide was immobilized on the surface of GaAs, which was transparent to mid-infrared light, and the interaction with its antibody was examined in aqueous media. We demonstrated that the binding of the antibody to the antigen immobilized on a GaAs surface selectively gave rise to beta-sheet amide I vibrations (1639 and 1690 cm(-1)), while no structurally related signals were induced by nonspecifically adsorbed proteins. The peak height of the P-peak (1639 cm(-1)) in the amide I band linearly increased with the antiserum concentration as well as that of the amide II band. The detection limit (S/N = 3) was a 1:36 000 dilution for the amide I signal. In addition, through the use of surface-sensitive MIR-FTIR, the present sensor selectively detected the antigen-antibody interactions at the surfaces without being affected by the presence of bulk species, enabling rapid and wash-free detection. Our method provides not only rapid label-free detection of protein-protein interactions but a more accurate discrimination between specific and nonspecific interactions through the use of the secondary structure of the target proteins as a measure for the specific signals.
DNA hybridization detection by porous silicon-based DNA microarray in conjugation with infrared microspectroscopy Peer-reviewed

Ryo-taro Yamaguchi, Ko-ichrio Miyamoto, Ken-ichi Ishibashi, Ayumi Hirano, Suhana Mohd Said, Yasuo Kimura, Michio Niwano

JOURNAL OF APPLIED PHYSICS　102　(1)　014303　2007/07
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.2751415 　

ISSN：0021-8979

More details Close

A method is described for the label-free detection of DNA hybridization on porous silicon (por-Si), based upon the pairing of oligonucleotide chemistry and standard silicon nanotechnology. Por-Si with a pore diameter of approximately 30 nm was used to immobilize probe DNA. Infrared microspectroscopy was employed to monitor the hybridization of probe-DNA immobilized on pore surfaces with its complementary DNA (target-DNA). The immobilization of probe DNA on por-Si facilitates hybridization detection for a small sensing area (approximately 50x50 mu m(2)) with a high detection efficiency. In this study, we fabricated a porous silicon-based DNA microarray (por-Si-microarray) using photolithographic and Si anodizing techniques. We demonstrate that DNA hybridization can be detected on a por-Si-microarray through the analysis of infrared absorption spectral profiles in the region where the vibration modes of the bases appear. This present approach demonstrates that por-Si-microarray in conjugation with infrared microspectroscopy has potential application in DNA sensing chips. (c) 2007 American Institute of Physics.
Autophosphorylation of alpha CaMKII is not a general requirement for NMDA receptor-dependent LTP in the adult mouse Peer-reviewed

Sam F. Cooke, Jianqun Wu, Florian Plattner, Michael Errington, Michael Rowan, Marco Peters, Ayumi Hirano, Karl D. Bradshaw, Roger Anwyl, Timothy V. P. Bliss, K. Peter Giese

JOURNAL OF PHYSIOLOGY-LONDON　574　(3)　805-818　2006/08
Publisher: WILEY-BLACKWELL
DOI： 10.1113/jphysiol.2006.111559 　

ISSN：0022-3751

More details Close

Autophosphorylation of alpha-Ca(2+)/calmodulin kinase II (alpha CaMKII) at Thr(286) is thought to be a general effector mechanism for sustaining transcription-independent long-term potentiation (LTP) at pathways where LTP is NMDA receptor-dependent. We have compared LTP at two such hippocampal pathways in mutant mice with a disabling point mutation at the Thr(286) autophosphorylation site. We find that autophosphorylation of alpha CaMKII is essential for induction of LTP at Schaffer commissural-CA1 synapses in vivo, but is not required for LTP that can be sustained over days at medial perforant path-granule cell synapses in awake mice. At these latter synapses LTP is supported by cyclic AMP-dependent signalling in the absence of alpha CaMKII signalling. Thus, the autophosphorylation of alpha CaMKII is not a general requirement for NMDA receptor-dependent LTP in the adult mouse.
Real-time monitoring of L-glutamate release from mouse brain slices under ischemia with a glass capillary-based enzyme electrode Peer-reviewed

N Nakamura, K Negishi, A Hirano, M Sugawara

ANALYTICAL AND BIOANALYTICAL CHEMISTRY　383　(4)　660-667　2005/10
Publisher: SPRINGER HEIDELBERG
DOI： 10.1007/s00216-005-0033-6 　

ISSN：1618-2642

More details Close

Real-time monitoring of L-glutamate release from various neuronal regions of mouse hippocampal slices under ischemia (a glucose-free hypoxia condition) is described. A glass capillary microelectrode with a tip size of similar to 10 mu m containing a very small volume (similar to 2 mu L) of a solution of glutamate oxidase (GluOx) and ascorbate oxidase was used. First, the amperometric response behavior of the electrode at 0 V versus Ag/AgCI was characterized with a standard glutamate solution in terms of continuous measurements, effect of oxygen, viscosity of solution and concentration dependence. The electrode was applied to the real-time monitoring of L-glutamate released from different neuronal regions of acute hippocampal slices submerged in a hypoxia solution. The time-resolved amounts of L-glutamate released at various neuronal regions (CA1, CA3 and DG) of mouse hippocampal slices were quantified and compared with the reported L-glutamate fluxes using difference-image analysis during ischemia.
A dot-blot method for quantification of apurinic/apyrimidinic sites in DNA using an avidin plate and liposomes encapsulating a fluorescence dye Peer-reviewed

H Yanagisawa, A Hirano, M Sugawara

ANALYTICAL BIOCHEMISTRY　332　(2)　358-367　2004/09
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI： 10.1016/j.ab.2004.06.034 　

ISSN：0003-2697

More details Close

A dot-blot method for quantification of apurinic/apyrimidinic (AP) sites in genomic DNA (calf thymus DNA) is described using an avidin-modified glass slip and biotinylated liposomes containing sulforhodamine B as a fluorescence marker. Aldehyde reactive probe (ARP)-tagged DNA was found to be strongly adsorbed on an avidin slip, even if treated with ethanolamine and biotin, with an efficiency of 51% due to the positive surface charge of avidin, and unbound ARP was easily washed out of the surface with Milli-Q water. In the assay protocol, calf thymus DNA containing AP sites is reacted with ARP in solution and immobilized on an ethanolamine- and biotin-treated avidin slip (EAB-avidin slip), followed by incubation with streptavidin. The AP sites were finally quantified with biotinylated liposomes containing 1.5 mM sulforhodamine B as a fluorescence marker. The mean fluorescence intensity over the surface of the slip was an analytically relevant measure of the amount of AP sites in calf thymus DNA. By using the dot-blot assay, 1-5 AP sites per 10(4) nucleotides in 5 and 100ng of DNA were quantified. The current dot-blot method has potential for quantification of AP sites in genomic DNA at a level of several nanograms. (C) 2004 Elsevier Inc. All rights reserved.
Acute effect of corticosterone on N-methyl-D-aspartate receptor-mediated Ca2+ elevation in mouse hippocampal slices Peer-reviewed

S Sato, H Osanai, T Monma, T Harada, A Hirano, M Saito, S Kawato

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS　321　(2)　510-513　2004/08
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI： 10.1016/j.bbrc.2004.06.168 　

ISSN：0006-291X

More details Close

We examined the rapid effects of corticosterone (CORT) on N-methyl-D-aspartate (NMDA) receptor-mediated Ca2+ signals in adult mouse hippocampal slices by using Ca2+ imaging technique. Application of NMDA caused a transient elevation of intracellular Ca2+ concentration followed by a decay to a plateau within 150 s. The 30 min preincubation of CORT induced a significant decrease of the peak amplitude of NMDA-induced Ca2+ elevation in the CA1 region. The rapid effect of CORT was induced at a stress-induced level (0.4-10 muM). Because the membrane non-permeable bovine serum albumin-conjugated CORT also induced a similar rapid effect, the rapid effect of CORT might be induced via putative surface CORT receptors. In contrast, CORT induced no significant effects on NMDA-induced Ca2+ elevation in the dentate gyrus. In the CA3 region, CORT effects were not evaluated, because the marked elevation of NMDA-induced Ca2+ signals was not observed there. (C) 2004 Elsevier Inc. All rights reserved.
Single-channel recordings of gramicidin at agarose-supported bilayer lipid membranes formed by the tip-dip and painting methods Peer-reviewed

Y Matsuno, C Osono, A Hirano, M Sugawara

ANALYTICAL SCIENCES　20　(8)　1217-1221　2004/08
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/analsci.20.1217 　

ISSN：0910-6340

More details Close

Agarose-supported BLMs were prepared by the tip-dip and painting methods, and single-channel recordings of gramicidin were examined for the development of an ion-channel sensor. The supported BLMs formed by the tip-dip method had an electric resistance of >1.0 x 10(11) Omega and a longer lifetime as compared with unsupported ones, which enabled single-channel recordings of gramicidin. The supported BLMs formed by the painting method also enabled single-channel recordings, but the lifetime was shorter than that of unsupported planar BLMs formed by the monolayer folding method.
An excised patch membrane sensor for arachidonic acid released in mouse hippocampal slices under stimulation of L-glutamate Peer-reviewed

H Saitoh, Y Namatame, A Hirano, M Sugawara

ANALYTICAL BIOCHEMISTRY　329　(2)　163-172　2004/06
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI： 10.1016/j.ab.2004.03.060 　

ISSN：0003-2697

More details Close

An excised patch membrane sensor for arachidonic acid (AA) is described, whose response stems from AA-induced channel-type transport of ions across the excised patch membrane. The patch membrane sensor was prepared in situ by excising mouse hippocampal cell membranes with patch pipets having a tip diameter of < 0.5 mum. The sensor responds to AA, giving rise to a channel-type current, and its magnitude (apparent conductance) increased with increasing AA concentration in the range from 10 to 30nM. The detection limit was 2.1 nM (S/N= 3). The induction of channel-type currents was selective to AA over fatty acids such as palmitic acid, stearic acid, oleic acid, gamma-linolenic acid, and docosahexaenoic acid and AA metabolites such as 12-HETE, 5-HETE, and prostaglandin D-2. The sensor was applied to quantification of AA released from various neuronal regions (CA1, CA3, and DG) of mouse hippocampus under stimulation Of 100 muM L-glutamate. The release of AA from each region was observed 1 min after the stimulation and the concentration of AA 5 min after the stimulation varied among the neuronal sites, i.e., 8 +/- 1 nM (n = 5) for CA1, 15 +/- 3 nM (n = 3) for CA3, and 6 +/- 2 nM (n = 9) for DG. The L-glutamate-evoked release of AA was partly inhibited by ionotropic glutamate receptor antagonists (APV and DNQX) and completely blocked by phospholipase A(2) (PLA(2)) inhibitor (MAFP), suggesting that the release of AA occurred by glutamate receptor- mediated activation of PLA(2). The potential use of the present sensor for detecting local concentration of AA at various neuronal sites is discussed. (C) 2004 Elsevier Inc. All rights reserved.
Imaging of L-glutamate fluxes in mouse brain slices based on an enzyme-based membrane combined with a difference-image analysis Peer-reviewed

A Hirano, N Moridera, M Akashi, M Saito, M Sugawara

ANALYTICAL CHEMISTRY　75　(15)　3775-3783　2003/08
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/ac030088+ 　

ISSN：0003-2700

More details Close

A time-resolved imaging method for visualizing L-glutamate release in mammalian brain slices is proposed by using an enzyme membrane combined with a difference-image analysis. The enzyme membrane is composed Of L-glutamate oxidase and horseradish peroxidase incorporated into a bovine serum albumin matrix. L-Glutamate triggers an enzyme-coupling reaction to convert a redox substrate (DA-64) to Bindschedler's Green, which gives a green color signal. The difference-image analysis is based on calculating slopes of a signal versus time (t) plot in the time range from (t - 40 s) to (t + 40 s) for visualizing L-glutamate release in terms of its flux (in mol min(-1) cm(-2)). The method was applied to a time-resolved imaging of hippocampal distribution of ischemia-induced L-glutamate release in mouse brain slices. The image of L-glutamate distribution showed that the level and time courses of L-glutamate fluxes were neuronal region-dependent The maximum flux of L-glutamate at CA1 was observed at 7.7 min after ischemia. The flux at 7.7 min increased in the order of CA1 approximate to CA3 > DG. The time course of the L-glutamate flux in the CA1 region was biphasic and that in the DG region was modestly biphasic. In the CA3 region, such biphasic release of L-glutamate was not seen. The ischemia-induced L-glutamate flux was accelerated when Mg2+ was omitted from an extracellular solution. The present enzyme membrane-based approach provides a useful method for visualizing distribution of L-glutamate release in the brain slices during ischemia.
A single-channel sensor based on gramicidin controlled by molecular recognition at bilayer lipid membranes containing receptor Peer-reviewed

A Hirano, M Wakabayashi, Y Matsuno, M Sugawara

BIOSENSORS & BIOELECTRONICS　18　(8)　973-983　2003/08
Publisher: ELSEVIER ADVANCED TECHNOLOGY
DOI： 10.1016/S0956-5663(02)00219-1 　

ISSN：0956-5663

More details Close

A novel ion-channel sensor based on a membrane bound receptor and a single gramicidin channel is described, in which the binding of an analyte to the membrane bound receptor modulates the single-channel activity of gramicidin. The sensor is composed of a planar bilayer lipid membrane (BLM) containing biotin-labeled phosphatidylethanolamine as receptor for avidin and gramicidin as signal transducer. When the receptor catches an analyte (avidin or ferritin-labeled avidin (FA)) at the membrane surface, the bilayer structure is locally distorted and the gramicidin monomer/dimer kinetics is modulated in a manner that the fraction of channel opening with a short lifetime (less than or equal to 100 ms) to the total opening events increases. The fraction was found to increase with the concentration of avidin from 1.0 x 10(-9) to 1.0 X 10(-6) M and of FA from 1.0 x 10(-9) to 1.0 x 10(-8) M. With dinitrophenyl-labeled PE embedded as receptor in the BLM for monoclonal anti-dinitrophenyl antibody (anti-DNP), the fraction of channel openings (less than or equal to 100 ms) increased with the concentration of anti-DNP from 2.0 x 10(-9) to 2.0 x 10(-7) g/ml. Bovine serum albumin (BSA) and anti-BSA antibody caused no changes in the channel opening. The possible mechanism of analyte-induced modulation of single-channel activity of gramicidin is also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
Arachidonic acid-induced channel- and carrier-type ion transport across planar bilayer lipid membranes Peer-reviewed

A Hirano, Y Namatame, E Wakaizumi, Y Matsuno, M Sugawara

ANALYTICAL SCIENCES　19　(2)　191-197　2003/02
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/analsci.19.191 　

ISSN：0910-6340

More details Close

Transmembrane ion transport by arachidonic acid (AA) through bilayer lipid membranes (BLMs) was investigated by means of electrochemical measurements to provide a basis for designing a sensor membrane. We found that AA induces a channel-type current, in addition to a carrier-type current, across planar BLMs. A linear relation between the logarithmic value of the AA concentration and the current responses (given as integrated currents) was observed for a carrier-type current, while a sigmoid relation was found for a channel-type current. Although AA transports Na+, Ca2+ and Mg2+ and exhibits ion selectivity between Na+ and Mg2+ for the carrier-type current, ion transport for the channel-type current was non-selective. It was found that ion transport via the channel mechanism occurs frequently for AA, while channel-type currents were only occasionally observed for gamma-linolenic acid and prostaglandin D-2. No channel-type currents were induced by other fatty acids (oleic, linoleic, stearic, myristic, eicosapentanoic and docosahexanoic acids) and metabolites of AA (12-HETE and 5-HETE). The carrier-type ion transport occurs selectively to these compounds if the concentration is below 1.0 muM. These results suggest that AA selectively facilitates an ion flux through the BLMs, generating channel-type and/or carrier-type currents, which can be used as a measure of the AA concentration.
A glass capillary microelectrode based on capillarity and its application to the detection of (L)-glutamate release from mouse brain slices Invited Peer-reviewed

K Nakajima, T Yamagiwa, A Hirano, M Sugawara

ANALYTICAL SCIENCES　19　(1)　55-60　2003/01
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/analsci.19.55 　

ISSN：0910-6340

More details Close

A new glass capillary microelectrode for L-glutamate is described using pulled glass capillaries (tip size, similar to12.5 mum) with a very small volume (similar to2 mu1) of inner solution containing glutamate oxidase (GluOx) and ascorbate oxidase. The operation of the electrode is based on capillary action that samples L-glutamate into the inner solution. The enzyme reaction by GluOx generates hydrogen peroxide that is detected at an Os-gel-HRP polymer modified Pt electrode in a three-electrode configuration. The amperometric response behavior of the electrode was characterized in terms of the capillarity, response time, sensitivity and selectivity for measurements of L-glutamate. The currents at 0 V vs. Ag/AgCl increased linearly with the L-glutamate concentration from 10 to 150 muM for in vitro and in situ calibrations. The response was highly selective to L-glutamate over ascorbate, dopamine, serotonin and other amino acids. The detection of L-glutamate in the extracellular fluids of different regions of mouse hippocampal slices under stimulation of KCl was demonstrated.
Potentiometric responses of polymeric liquid membranes based on hydrophobic chelating agents to metal ions Peer-reviewed

Y Itoh, Y Ueda, A Hirano, M Sugawara, K Tohda, H Akaiwa, Y Umezawa

ANALYTICAL SCIENCES　17　(5)　621-627　2001/05
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/analsci.17.621 　

ISSN：0910-6340

More details Close

The effect of hydrophobicity of acidic chelating agents as sensing materials on the potentiometric responses of polymeric liquid membranes was investigated. The chelating agents tested were 8-quinolinol (HOx), dithizone (HDz), 1-(2pyridylazo)-2-naphthol (PAN) and their alkylated analogues, 5-octyloxymethyl-8-quinolinol (HO8Q), di(p-hexylphenyl)thiocarbazone (C6HDz), 7-pentadecyloxy-1-(2-pyridylazo)-2-naphthol (C15PAN) and a series of N-alkylcarbonyl-N-phenylhydroxylamines (CnPHA, n = 3, 6, 9, 12). The distribution coefficients between membrane solvent and water were determined to evaluate the hydrophobicity of the agents. The potential-pH profiles of the membranes containing hydrophobic chelating agents demonstrated the generation of potentiometric responses, while less hydrophobic agents gave no response. A possible model for the generation of membrane potential is proposed. The charge separation is attained by the permselective uptake of metal cations by the chelating agent anion at membrane/solution interface, where the high hydrophobicity of the agent enables the anionic or deprotonated form of the agents to remain at the membrane/solution interface.
A single-channel method for evaluation of very magnitudes of Ca2+ ion fluxes through epsilon 4/zeta 1 N-methyl-D-aspartate receptor channels in bilayer lipid membranes Peer-reviewed

M Wakabayashi, A Hirano, M Sugawara, S Uchino, S Nakajima-Iijima

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS　24　(3)　453-460　2001/01
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
DOI： 10.1016/S0731-7085(00)00467-2 　

ISSN：0731-7085

More details Close

A single-channel method for evaluating agonist selectivity in terms of the very number of Ca2+ ions passed through the epsilon4/zeta1 N-methyl-D-aspartate (NMDA) receptor ion channel in bilayer lipid membranes (BLMs) is described. The number of Ca2+ passed through the single-channel was obtained from single-channel recordings in a medium where the primary permeant ion is Ca2+. The recombinant epsilon4/zeta1 NMDA channel was partially purified from Chinese hamster ovary cells expressing the channel and incorporated in BLMs formed by the tip-dip method. It was found that the epsilon4/zeta1 channel in BLMs is permeable to Ca2+ and Na+, but the number of Ca2+ passed through the channel is much fewer than that of Na+. The integrated Ca2+ currents induced by three typical agonists NMDA, L-glutamate and L-CCG-IV were obtained at concentration of 50 muM, where the integrated currents for all the agonists reached their saturated values. The integrated Ca2+ currents obtained are (3.1 +/- 0.21) x 10(-13) C/s for NMDA, (4.6 +/- 0.31) x 10(-13) C/s for L-glutamate and (5.7 +/- 0.25) x 10(-13) C/s for L-CCG-IV, respectively, suggesting that the three kinds of agonists have different efficacies to induce permeation of Ca2+. The range of the agonist selectivity thus obtained is much narrower than that of binding affinities for the NMDA receptors from rat brain. The present method is able to detect Ca2+ permeation with a detection limit of approximate to 10(5) Ca2+ ions/s. (C) 2001 Elsevier Science B.V. All rights reserved.
An Ion-Channel Sensor for Abasic Sites in DNA Peer-reviewed

N. Simokawa, A. Hirano, M. Sugawara

Anal. Sci. (supplement)　17　i1379-i1382　2001
A glass capillary ultramicroelectrode with an electrokinetic sampling ability Peer-reviewed

A Hirano, M Kanai, T Nara, M Sugawara

ANALYTICAL SCIENCES　17　(1)　37-43　2001/01
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/analsci.17.37 　

ISSN：0910-6340

eISSN：1348-2246

More details Close

A glass capillary ultramicroelectrode (tip diameter approximate to1.2 mum) having an electrokinetic sampling ability is described. It is composed of a pulled glass capillary filled with an inner solution and three internal electrodes (Pt working and counter electrodes and an Ag/AgCl reference electrode). The voltammetric response of the capillary electrode is based on electrokinetic transport of analyte ions from the sample solution into the inner solution across the conical tip. It was found that the electrophoretic migration of analytes at the conical tip is faster than electroosmotic flow, enabling electrokinetic transport of analyte ions into the inner solution of the electrode. By using [Fe(CN)(6)](4-) and (ferrocenylmethyl)trimethylammonium (FcTMA(+)) ions as model analytes, differential pulse voltammetric responses of the capillary electrode were investigated in terms of tip diameter of the capillary, sampling voltage, sampling time, detection limit and selectivity. The magnitude of the response depends on the size and charge of analyte ions. With a capillary electrode having a approximate to1.2-mum tip diameter, which minimizes non-selective diffusional entry of analytes, the response after 1 h sampling at + 1.7 V is linearly related to [Fe(CN)(6)](4-) concentration in the range of 0.50 - 5.0 mM with the detection limit of 30 muM. Application of a potential of the same sign as that of the analyte ion forces the analyte to move out from the electrode to the solution, enabling reuse of the same capillary electrode. The charge-selective detection of analytes with the capillary electrode is demonstrated for [Fe(CN)(6)](4+) in the presence of FcTMA(+).
Evaluation and comparison of ion permeation and agonist selectivities for N-methyl-D-aspartate receptor channels with different subunit compositions in bilayer lipid membranes based on integrated single-channel currents Peer-reviewed

A Hirano, M Wakabayashi, M Sugawara, S Uchino, S Nakajima-Iijima

ANALYTICAL BIOCHEMISTRY　283　(2)　258-265　2000/08
Publisher: ACADEMIC PRESS INC
DOI： 10.1006/abio.2000.4650 　

ISSN：0003-2697

More details Close

To quantify the ion-permeation ability of the recombinant epsilon 1-4/zeta 1 channel activated by agonists, the magnitude of agonist-induced integrated single-channel currents for the epsilon 2-4/zeta 1 N-methyl-D-aspartate (NMDA) channels in bilayer lipid membranes (BLMs) was evaluated electrochemically based on the single-channel recordings. The recombinant epsilon 2-4/zeta 1 channels were purified from Chinese hamster ovary cells expressing each channel and incorporated in BLMs formed by the tip-dip method. Three typical agonists, L-glutamate, NMDA, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (L-CCG-IV), were investigated at a concentration of 50 mu M. The magnitude of L-glutamate-induced integrated current was found to depend on the E-subunit composition and to increase in the order of epsilon 2/zeta 1 > epsilon 1/zeta 1 approximate to epsilon 4/zeta 1 > epsilon 3/zeta 1, which differs from that of the reported binding affinities (EC50) between L-glutamate and each channel type. On the other hand, the magnitude of the integrated currents induced by NMDA and L-CCG-IV did not vary among the four channel types. The order of agonist selectivity toward the epsilon 2-4/zeta 1 channels in terms of the magnitude of the integrated current was L-glutamate > L-CCG-IV approximate to NMDA for the epsilon 2/zeta 1 channel, L-CCG-IV > NMDA > L-glutamate for the epsilon 3/zeta 1 channel, and L-CCG-IV approximate to L-glutamate > NMDA for the epsilon 4/zeta 1 channel, suggesting that the agonist selectivity also depends on the E-subunit composition. The present study shows that each epsilon 1-4/zeta 1 channel has its own ability of ion permeation, i.e., its own signal transduction ability, which is not parallel to its binding ability. (C) 2000 Academic Press.
Evaluation of agonist selectivity for the NMDA receptor ion channel in bilayer lipid membranes based on integrated single-channel currents Peer-reviewed

A Hirano, M Sugawara, Y Umezawa, S Uchino, S Nakajima-Iijima

BIOSENSORS & BIOELECTRONICS　15　(3-4)　173-181　2000/06
Publisher: ELSEVIER ADVANCED TECHNOLOGY
DOI： 10.1016/S0956-5663(00)00058-0 　

ISSN：0956-5663

More details Close

A new method for evaluating chemical selectivity of agonists to activate the N-methyl-D-aspartate (NMDA) receptor was presented by using typical agonists NMDA, L-glutamate and (2S, 3R, 4S)-2-(carboxycyclopropyl)glycine (L-CCG-IV) and the mouse epsilon 1/zeta 1 NMDA receptor incorporated in bilayer lipid membranes (BLMs) as an illustrative example. The method was based on the magnitude of an agonist-induced integrated single-channel current corresponding to the number of total ions passed through the open channel. The very magnitudes of the integrated single-channel currents were compared with the different BLMs as a new measure of agonist selectivity. The epsilon 1/zeta 1 NMDA receptor was partially purified from Chinese hamster ovary (CHO) cells expressing the epsilon 1/zeta 1 NMDA receptor and incorporated in BLMs formed by the tip-dip method. The agonist-induced integrated single-channel currents were obtained at 50 mu M agonist concentration, where the integrated current for NMDA was shown to reach its saturated value. The obtained integrated currents were found to be (4.5 +/- 0.55) x 10(-13) C/s for NMDA, (5.8 +/- 0.72) x 10(-13) C/s for L-glutamate and (6.6 +/- 0.61) x 10(-13) C/s for L-CCG-IV, respectively. These results suggest that the agonist selectivity in terms of the total ion flux through the single epsilon 1/zeta 1 NMDA receptor is in the order of L-CCG-IV approximate to L-glutamate > NMDA. (C) 2000 Elsevier Science S.A. All rights reserved.
Detection and imaging of L-glutamate released from mouse-brain slices with an enzyme-based membrane Peer-reviewed

A Hirano, M Asakawa, N Kido, M Sugawara

ANALYTICAL SCIENCES　16　(1)　25-29　2000/01
Publisher: JAPAN SOC ANALYTICAL CHEM
DOI： 10.2116/analsci.16.25 　

ISSN：0910-6340

More details Close

A new and simple method for detecting and color imagine of L-glutamate released in mouse-brain slices is described based on an enzyme-coupling reaction. The method utilizes L-glutamate oxidase (GluOx) and horseradish peroxidase (HRP) immobilized in a bovine serum albumin (BSA)-glutaraldehyde matrix on a poly-L-lysine-coated glass cover slip. The enzymes are spontaneously and continuously supplied from the membrane into an extracellular solution of the brain slice placed on the membrane after dipping in a redox substrate (DA-64). The Bindschedler's Green (BG) converted from the DA-64 by the enzyme reaction gives green signals in the brain slice. which are related to the concentration of L-glutamate released in its regions. The first examples of color images for the spatial distribution of L-glutamate in the regions of adult mouse brain slices are demonstrated. The regions where the intense green signals were observed matched the reported distribution of mRNAs encoding the NMDA receptor in the mouse-brain slice.
A method for evaluating chemical selectivity of agonists for glutamate receptor channels incorporated in liposomes based on an agonist-induced ion flux measured by ion-selective electrodes Peer-reviewed

H Radecka, J Nakanishi, A Hirano, M Sugawara, Y Umezawa

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS　19　(1-2)　205-216　1999/02
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
DOI： 10.1016/S0731-7085(98)00146-0 　

ISSN：0731-7085

More details Close

A new method for evaluating chemical selectivity of agonists for the NMDA subtype of glutamate receptor (GluR) channels is described. The method is based on the magnitude of Ca2+ release from GluR-incorporated liposomes, which is measured by a Ca2+ ion-selective electrode with a thin-layer mode. The partially purified GluRs from rat whole brain were reconstituted into Ca2+-loaded liposomes. Small aliquots (each 50 mu l) of the proteoliposomes, in the presence of an antagonist DNQX for blocking non-NMDA subtype, were subjected to potentiometric measurements of Ca2+ release under stimulation by three kinds of agonists, i.e. NMDA, L-glutamate and L-CCG-IV. The amount of the Ca2+-ion flux through the GluR channel induced by the agonists was found to increase in the order of NMDA < L-glutamate < L-CCG-IV, which was consistent with that of binding affinity of the agonists toward the NMDA subtype. However, the range of selectivity of the relevant agonists was much smaller compared with results based on binding affinities. The present method provides physiologically more relevant values for the agonist selectivity of GluRs as compared to that of the conventional binding assay in the sense that the selectivity is based on the very magnitude of Ca2+ flux through the NMDA receptor, i.e. the extent of signal transduction by a given agonist. The evaluation of agonist selectivity based on Na+ release was also investigated by using a Na+ ion-selective electrode, but agonist-induced Na+ release was not detected, because of low permeability of Na+ through the NMDA subtype. (C) 1999 Elsevier Science B.V. All rights reserved.
Electrochemical evaluation of chemical selectivity of glutamate receptor ion channel proteins with a multi-channel sensor Peer-reviewed

M Sugawara, A Hirano, M Rehak, J Nakanishi, K Kawai, H Sato, Y Umezawa

BIOSENSORS & BIOELECTRONICS　12　(5)　425-439　1997
Publisher: ELSEVIER ADVANCED TECHNOLOGY
DOI： 10.1016/S0956-5663(97)00005-5 　

ISSN：0956-5663

More details Close

A new method for evaluating chemical selectivity of agonists towards receptor ion channel proteins is proposed by using glutamate receptor (GluR) ion channel proteins and their agonists N-methyl-D-aspartic acid (NMDA), L-glutamate, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (L-CCGIV). Integrated multi-channel currents, corresponding to the sum of total amount of ions passed through the multiple open channels, were used as a measure of agonists' selectivity to recognize ion channel proteins and induce channel currents. GluRs isolated from rat synaptic plasma membranes were incorporated into planar bilayer lipid membranes (BLMs) formed by the folding method. The empirical factors that affect the selectivity were demonstrated: (i) the number of GluRs incorporated into BLMs varied from one membrane to another; (ii) each BLM contained different subtypes of GluRs (NMDA and/or non-NMDA subtypes); and (iii) the magnitude of multi-channel responses induced by L-glutamate at negative applied potentials was larger than at positive potentials, while those by NMDA and L-CCG-IV were linearly related to applied potentials. The chemical selectivity among NMDA, L-glutamate and L-CCG-IV for NMDA subtype of GluRs was determined with each single BLM in which only NMDA subtype of GluRs was designed to be active by inhibiting the non-NMDA subtypes using a specific antagonist DNQX. The order of selectivity among the relevant agonists for the NMDA receptor subtype was found to be L-CCG-IV>L-glutamate>NMDA, which is consistent with the order of binding affinity of these agonists towards the same NMDA subtypes. The potential use of this approach for evaluating chemical selectivity towards non-NMDA receptor subtypes of GluRs and other receptor ion channel proteins is discussed. (C) 1997 Elsevier Science Limited.
光触媒作用を用いた液中表面改質による培養神経細胞の操作

山本英明, 平野愛弓, 谷井孝至, 庭野道夫

表面科学37,224-229(2016).

Show all ︎Show first 5

Misc. 167

Modular Topology Enhances Reservoir Computing Performance in Biological Neuronal Networks

Sumi Takuma, Yamamoto Hideaki, Katori Yuichi, Ito Koki, Sato Shigeo, Hirano-Iwata Ayumi

IEICE Proceeding Series　76　687-688　2023/09/21
Publisher: The Institute of Electronics, Information and Communication Engineers
DOI： 10.34385/proc.76.d2l-11 　

eISSN：2188-5079

More details Close

Reservoir computing is a machine learning paradigm that employs high-dimensional dynamical systems for information processing. Although biological neuronal networks (BNNs) have been utilized to implement reservoir computing to provide insight into their computation properties, the neurons in conventional cultured neuronal networks are randomly connected, generating atypical dynamics characterized by highly correlated bursting activity not observed in healthy brains. In this study, we used micropatterning technology to fabricate BNNs with modular topology, a structural feature conserved in brain networks, and to understand how the dynamics within non-random networks of neuronal cells are linked to computing. Our study demonstrated that the modular BNN reservoir is capable of classifying both image and time-series data above chance levels. The modular structure in BNN contributes to the increased reservoir computing performance, in line with previous computational models with neuromorphic networks. Combining experiments with biological neuronal network and computational modeling can advance our understanding of computing principles in multicellular neuronal networks.
Bottom-Up Investigation of Multicellular Computing Within Biological Neuronal Networks

Yamamoto Hideaki, Sumi Takuma, Sato Yuya, Sato Shigeo, Hirano-Iwata Ayumi

IEICE Proceeding Series　76　594-595　2023/09/21
Publisher: The Institute of Electronics, Information and Communication Engineers
DOI： 10.34385/proc.76.c4l-11 　

eISSN：2188-5079

More details Close

In this presentation, we will first introduce our studies aimed at reproducing an evolutionarily-conserved net-work structure in cultured neuronal networks on engineered glass coverslips and CMOS-based high-density microelectrode arrays. We then describe our recent attempts to couple the engineered neuronal networks with external stimulation to reveal their response to noise and spatiotemporally-patterned inputs to show that bioengineering technologies offer novel tools in investigating computational aspects of multicellular networks of biological neurons.
マイクロ流体デバイスを用いた神経回路機能の実細胞再構成 Invited

山本英明, 平野愛弓, 佐藤茂雄

応用物理　92　(5)　278-282　2023/05/01

DOI： 10.11470/oubutsu.92.5_278 　
Modular architecture facilitates noise-driven control of synchrony in neuronal networks

Hideaki Yamamoto, F. Paul Spitzner, Taiki Takemuro, Victor Buendía, Carla Morante, Tomohiro Konno, Shigeo Sato, Ayumi Hirano-Iwata, Viola Priesemann, Miguel A. Muñoz, Johannes Zierenberg, Jordi Soriano

arXiv preprint　2205　10563　2022/05

DOI： 10.48550/arXiv.2205.10563 　
ショットガス吹き付け方式を用いたガス濃度測定—Gas concentration measurement using shot gas spraying method

阿部宏之, 岩田一樹, 馬騰, 但木大介, 平野愛弓, 木村康男, 庭野道夫

「センサ・マイクロマシンと応用システム」シンポジウム論文集電気学会センサ・マイクロマシン部門 [編]　38　6p　2021/11
Publisher: Institute of Electrical Engineers of Japan
活性酸素によるナノバブルの殺菌効果

山口政人, 渡部芳彦, 馬騰, 但木大介, 金高弘恭, 平野愛弓, 庭野道夫

感性福祉研究所年報　(22)　77-86　2021/03
Publisher: 東北福祉大学感性福祉研究所
ISSN：1344-9966

More details Close

大腸菌をモデル細菌として用いてナノバブル(NB)の殺菌活性を調べた。ナノバブルは、ナノスケールの直孔を規則的に配列させた多孔質アルミナ膜を用いて作製した。ナノバブルの殺菌活性を評価するために、NB懸濁液中に細菌を留置した。殺菌活性は、細菌培地上にコロニー化した生細胞の数から求めた生存率で推定した。二酸化炭素(CO2)、酸素(O2)、窒素(N2)の3種類のガスを含むNB水に曝露した場合の細菌の生存率を調べた結果、CO2を含むNB水に曝露すると細菌の生存率が有意に低下することがわかった。酸素ガス、窒素ガスを含むNB水に曝露しても、有意な殺菌効果は認められなかった。O2 NB水に曝露した場合には、大腸菌の増殖が観察された。NB懸濁液中の活性酸素の発生を電子スピン共鳴分光法(ESR)で調べた。その結果、NB懸濁液中に発生する活性酸素の主なものは水酸基ラジカル(OH・)であり、活性酸素の発生はCO2 NB水の場合に最も強く、殺菌効果測定の結果と一致することがわかった。(著者抄録)
Parallel recordings of hERG channel currents using a solvent-free lipid bilayer microarray

Tadaki Daisuke, Miyata Ryusuke, Yamaura Daichi, Araki Shun, Sato Madoka, Komiya Maki, Ma Teng, Yamamoto Hideaki, Niwano Michio, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2021.1　2147-2147　2021/02/26
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2021.1.0_2147 　

eISSN：2436-7613
Interfacial structure and size distribution of nanobubbles

Niwano Michio, Iwata Kazuki, Ma Teng, Tadaki Taisuke, Hirano-Iwata Ayumi

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2021　3Ea02　2021
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/jvss.2021.0_3ea02 　

eISSN：2434-8589

More details Close

We have investigated the particle size distribution of nanobubbles (NBs) the nanoparticle tracking analysis method and found that the particle size is discrete and increases by a factor of √2. We interpreted that this peculiar particle size distribution is caused by the fact that NBs of the same size tend to coalesce with each other, and simulated the particle size distribution incorporating this effect, and found that it can generally reproduce the experiment. The results of recent studies on the interfacial structure of NBs will also be presented.
Introduction of lateral voltage as a new input for artificial lipid bilayer systems

Watanabe Takaya, Sato Madoka, Komiya Maki, Kanomata Kensaku, Ma Teng, Tadaki Daisuke, Hirose Fumihiko, Hirano Ayumi

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2021　3Ea03　2021
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/jvss.2021.0_3ea03 　

eISSN：2434-8589

More details Close

Phospholipid bilayer is the basic structure of cell membranes. Artificially formed planar bilayer lipid membrane (BLM) has been widely used as a system for the functional analysis of membrane proteins. However, the measurement method has remained unchanged for several decades. Transmembrane voltage is usually used as the input, and the measured transmembrane current is used as the output of the system. In this work, we propose a method to improve the control of the BLM system by applying a voltage parallel to the BLM (lateral voltage) in addition to the traditional transmembrane voltage. The effects of the lateral voltage on the ion-channel-incorporated BLM systems were investigated.
集積化ガスセンサへの機械学習の適用—Application of machine learning to integrated gas sensor

阿部宏之, 岩田一樹, 馬騰, 但木大介, 平野愛弓, 木村康男, 庭野道夫

「センサ・マイクロマシンと応用システム」シンポジウム論文集電気学会センサ・マイクロマシン部門 [編]　37　6p　2020/10
Publisher: Institute of Electrical Engineers of Japan
Biomimetic Culture of Primary Neurons on an Ultrasoft Gel Surface Peer-reviewed

Takuma SUMI, Hideaki YAMAMOTO, Ayumi HIRANO-IWATA

Vacuum and Surface Science　63　(6)　298-303　2020/06/10
Publisher: Surface Science Society Japan
DOI： 10.1380/vss.63.298 　

ISSN：2433-5835

eISSN：2433-5843

More details Close

Mechanical properties of scaffolds have recently been found to impose strong impact on the behavior of cultured cells. Here, we focused on the effect of scaffold's elastic modulus on the development of synaptic connections in cultured neurons, and developed a novel system for culturing rat cortical neurons on an ultrasolft gel surface with an elastic modulus resembling the brain.
脳組織に近い弾性率を有するシリコーン樹脂の生体界面材料応用

山本英明, 住拓磨, 佐藤茂雄, 平野愛弓

Molecular Electronics and Bioelectronics　31　(2)　77-80　2020/05
Publisher: 応用物理学会有機分子・バイオエレクトロニクス分科会
ISSN：2423-8805
Fabrication of two-dimensional pressure mapping sensors based on organic ferroelectric films

119　(431)　61-63　2020/02/28
Publisher: 電子情報通信学会
ISSN：0913-5685
Fabrication of structurally different titanium oxide nanotube films on a chip

119　(431)　65-68　2020/02/28
Publisher: 電子情報通信学会
ISSN：0913-5685
Bio-hybrid membrane as a platform for new nanodevices

Ma Teng, Feng Xingyao, 但木大介, 平野愛弓

日本表面真空学会学術講演会要旨集(Web)　2020　(0)　184-184　2020
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/jvss.2020.0_184 　

ISSN：2434-8589

More details Close

In this presentation, a new platform based on bio-hybrid membranes will be proposed and discussed in detail. The bio-hybrid membrane is a 2D structure composed of lipid molecules and functional nanomaterials. It has the advantage of lipid bilayer structure, such as flowability, ultrathin thickness and ultrahigh resistance. At the same time, it possesses optical, electrical, magnetic functionality of the nanomaterials. Furthermore, due to the unique molecular packing in the structure, new properties can be discovered from the bio-hybrid membrane. Using the bio-hybrid membrane, we were able to discover unique properties and fabricate high-performance photodetectors and gas sensors. The bio-hybrid membrane introduced here is a flexible and feasible platform for novel nanodevices.
酸化チタンナノチューブ構造による集積化ガスセンサシステムの開発

阿部宏之, 馬騰, 但木大介, 平野愛弓, 平野愛弓, 岩田一樹, 庭野道夫

宮城県産業技術総合センター研究報告(Web)　(17)　2020

ISSN：1349-1741
Development of a hERG channel sensor for evaluation of drug side effects

渡辺恭也, 横田澪央, 加藤美生, 佐藤まどか, 但木大介, 小宮麻希, 山本英明, 井上遥香, 戸澤譲, 庭野道夫, 平野愛弓

電子情報通信学会技術研究報告　119　(431(CPM2019 91-109))　2020

ISSN：0913-5685
微細加工表面を用いた培養神経回路の構造機能制御―多細胞システムにおける情報処理の理解と応用を目指して― Invited Peer-reviewed

山本英明, 平野愛弓

電子情報通信学会論文誌C　J102-C　(12)　340-347　2019/12

ISSN：1881-0217
白金微粒子を坦持した酸化チタンナノチューブ薄膜を用いた高感度ガスセンサの応答特性—Response characteristics of a highly sensitive gas sensor with titanium oxide nanotube film decorated with platinum fine particles

阿部宏之, 馬騰, 但木大介, 平野愛弓, 木村康男, 庭野道夫

「センサ・マイクロマシンと応用システム」シンポジウム論文集電気学会センサ・マイクロマシン部門 [編]　36　5p　2019/11
Publisher: Institute of Electrical Engineers of Japan
Culturing primary neurons on an ultrasoft silicone gel with biomimetic stiffness

Sumi Takuma, Yamamoto Hideaki, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2019.2　2852-2852　2019/09/04
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2019.2.0_2852 　

eISSN：2436-7613
酸化チタンナノチューブ構造による集積化ガスセンサシステムの開発

阿部宏之, 馬騰, 但木大介, 平野愛弓, 平野愛弓, 庭野道夫

宮城県産業技術総合センター研究報告(Web)　(16)　65‐67 (WEB ONLY)　2019/08

ISSN：1349-1741
金属酸化物多孔質体を応用したガスセンサの開発

阿部宏之, 馬騰, 但木大介, 平野愛弓, 平野愛弓, 庭野道夫

宮城県産業技術総合センター研究報告(Web)　(16)　13‐16 (WEB ONLY)　2019/08

ISSN：1349-1741
Quantitative Analysis of Dynamical Complexity in Cultured Neuronal Network Models for Reservoir Computing Applications

Satoshi Moriya, Hideaki Yamamoto, Ayumi Hirano-Iwata, Shigeru Kubota, Shigeo Sato

Proceedings of the International Joint Conference on Neural Networks　2019-July　2019/07/01
Publisher: IEEE
DOI： 10.1109/IJCNN.2019.8852207 　

More details Close

© 2019 IEEE. Reservoir computing is a machine learning paradigm that was proposed as a model of cortical information processing in the brain. It processes information using the spatiotemporal dynamics of a large-scale recurrent neural network and is expected to improve power efficiency and speed in neuromorphic computing systems. Previous theoretical investigation has shown that brain networks exhibit an intermediate state of full coherence and random firing, which is suitable for reservoir computing. However, how reservoir performance is influenced by connectivity, especially which revealed in recent connectomics analysis of brain networks, remains unclear. Here, we constructed modular networks of integrate-and-fire neurons and investigated the effect of modular structure and excitatory-inhibitory neuron ratio on network dynamics. The dynamics were evaluated based on the following three measures: synchronous bursting frequency, mean correlation, and functional complexity. We found that in a purely excitatory network, the complexity was independent of the modularity of the network. On the other hand, networks with inhibitory neurons exhibited complex network activity when the modularity was high. Our findings reveal a fundamental aspect of reservoir performance in brain networks, contributing to the design of bio-inspired reservoir computing systems.
Poling treatment of PVDF films using thiol-modified gold surfaces

119　(9)　17-19　2019/04/18
Publisher: 電子情報通信学会
ISSN：0913-5685
Construction of an artificial cell membrane device and its application to a sensor for drug side effects

119　(9)　23-26　2019/04/18
Publisher: 電子情報通信学会
ISSN：0913-5685
Generation of nano-bubbles by a porous alumina thin film with ordered nano-holes.

Niwano Michio, Ma Teng, Tadaki Daisuke, Hirano-Iwata Ayumi

Abstract of annual meeting of the Surface Science of Japan　66th　(0)　163-163　2019
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/sssj2008.2018.0_163 　

More details Close

We have proposed a simple method of generating nano-bubbles (NBs) by a porous alumina film with ordered nano-scaled holes. We have investigated the size distribution of NBs generated by our proposed method using the nano tracking analysis (NTA). We found that the diameter of the NBs is in the range of 50-150 nm and depends on the kind of the gas in NBs.
白金微粒子を担持した酸化チタンナノチューブ薄膜を用いた高感度ガスセンサ

阿部宏之, MA Teng, 但木大介, 平野愛弓, 木村康男, 庭野道夫

電気学会全国大会講演論文集(CD-ROM)　2019　2019
Quantitative assessment of drug side effect on hERG channels based on artificial bilayer lipid membranes and cell-free expression system

横田澪央, 加藤美生, 山浦大地, 常田悠介, 佐藤まどか, 但木大介, 小宮麻希, 山本英明, 井上遥, 戸澤譲, 庭野道夫, 平野愛弓

電子情報通信学会技術研究報告　118　(461(CPM2018 101-120))　2019

ISSN：0913-5685
Controlled conductivity of fullerene doped lipid bilayer

Y. Yamaki, T. Haseyama, K. Kanomata, K. Yoshida, B. A. Arima, A. Hirano, F. Hirose

IEICE Technical Report　118　(461)　77-79　2019
人工脂質二重膜内で膜タンパク質の融合サイトとして働く微小ドメイン

メルヴィンゴー, ウェイシェン, 平野愛弓, 庭野道夫, 手老龍吾

電気学会研究会資料光・量子デバイス研究会　OQD-18-072　5-10　2018/12
微細加工シリコンチップに基づく人工細胞膜を用いた薬物副作用評価法

但木大介, 山浦大地, 馮興堯, 平野愛弓

生物物理　58　(6)　324-327　2018/11
Publisher: (一社)日本生物物理学会
DOI： 10.2142/biophys.58.324 　

ISSN：0582-4052
Fabrication of micro metal wire-embedded PVDF flexible pressure sensors

118　(9)　1-3　2018/04/19
Publisher: 電子情報通信学会
ISSN：0913-5685
Stable formation of an artificial cell membrane sensor and its application to sensing drug side effects

118　(9)　37-40　2018/04/19
Publisher: 電子情報通信学会
ISSN：0913-5685
イオンチャネル計測に用いられる脂質二重膜内のマイクロドメインのホスファチジルエタノールアミン濃度依存性

メルヴィンゴー, ウェイシェン, 平野愛弓, 庭野道夫, 手老龍吾

電子情報通信学会技術研究報告 (IEICE Technical Report)　118　(9)　49-52　2018/04
酸化チタンナノチューブ型高感度ガスセンサの開発

阿部宏之, 馬騰, 但木大介, 平野愛弓, 木村康男, 庭野道夫

感性福祉研究所年報 = Report of Kansei Fukushi Research Institute　(19)　67-77　2018/03
Publisher: 東北福祉大学感性福祉研究所
ISSN：1344-9966
Micro- and nanofabrication methods for ion channel reconstitution in bilayer lipid membranes

Daisuke Tadaki, Daichi Yamaura, Kohei Arata, Takeshi Ohori, Teng Ma, Hideaki Yamamoto, Michio Niwano, Ayumi Hirano-Iwata

Japanese Journal of Applied Physics　57　(3)　2018/03/01
Publisher: Japan Society of Applied Physics
DOI： 10.7567/JJAP.57.03EA01 　

ISSN：1347-4065 0021-4922

eISSN：1347-4065

More details Close

The self-assembled bilayer lipid membrane (BLM) forms the basic structure of the cell membrane and serves as a major barrier against ion movement. Ion channel proteins function as gated pores that permit ion permeation across the BLM. The reconstitution of ion channel proteins in artificially formed BLMs represents a well-defined system for investigating channel functions and screening drug effects on ion channels. In this review, we will discuss our recent microfabrication approaches to the formation of stable BLMs containing ion channel proteins as a potential platform for next-generation drug screening systems. BLMs formed in a microaperture having a tapered edge exhibited highly stable properties, such as a lifetime of ∼65 h and tolerance to solution changes even after the incorporation of the human ether-a-go-go-related gene (hERG) channel. We also explore a new method of efficiently incorporating human ion channels into BLMs by centrifugation. Our approaches to the formation of stable BLMs and efficient channel incorporation markedly improve the experimental efficiency of BLM reconstitution systems, leading to the realization of a BLM-based high-throughput platform for functional assays of various ion channels.
In situ modification of cell-culture scaffolds by photocatalysis of visible-light-responsive TiO2 film

Sho Kono, Kohei Furusawa, Atsushi Kurotobi, Kohei Hattori, Hideaki Yamamoto, Ayumi Hirano-Iwata, Takashi Tanii

Japanese Journal of Applied Physics　57　(2)　2018/02/01
Publisher: Japan Society of Applied Physics
DOI： 10.7567/JJAP.57.027001 　

ISSN：1347-4065 0021-4922

More details Close

We propose a novel process to modify the cell affinity of scaffolds in a cell-culture environment using the photocatalytic activity of visible-light (VL)-responsive TiO2. The proposed process is the improved version of our previous demonstration in which ultraviolet (UV)-responsive TiO2 was utilized. In that demonstration, we showed that cell-repellent molecules on TiO2 were decomposed and replaced with cell-permissive molecules upon UV exposure in the medium where cells are being cultured. However, UV irradiation involves taking the risk of inducing damage to the cells. In this work, a TiO2 film was sputter-deposited on a quartz coverslip at 640 °C without O2 gas injection to create a rutile structure containing oxygen defects, which is known to exhibit photocatalytic activity upon VL exposure. We show that the cell adhesion site and migration area can be controlled with the photocatalytic activity of the VL-responsive TiO2 film, while the cellular oxidative stress is reduced markedly by the substitution of VL for UV.
Biomimetic culture of primary neurons using ultrasoft gels

Sumi Takuma, Yamamoto Hideaki, Hayakawa Takeshi, Ide Katsuya, Kino Hisashi, Tanaka Tetsu, Hirano Ayumi

Abstract of annual meeting of the Surface Science of Japan　2018　180　2018
Publisher: The Japan Society of Vacuum and Surface Science
DOI： 10.14886/sssj2008.2018.0_180 　

More details Close

Mechanical properties of scaffolds have recently been found to impose strong impact on the behavior of cultured cells. Here, we focused on the effect of scaffold’s elastic modulus on the development of synaptic connections in cultured neurons, and established a novel system for culturing rat cortical neurons on an ultrasolft gel surface with an elastic modulus resembling the brain. Impact of the soft scaffold on the amplitude of synaptic currents and spontaneous neuronal activity, analyzed via patch -clamp recording and fluorescence calcium imaging, will also be presented.
微細成形技術を用いた機能性素子の開発-酸化チタンナノチューブ型ガスセンサの開発-

阿部宏之, 馬騰, 但木大介, 平野愛弓, 平野愛弓, 庭野道夫

宮城県産業技術総合センター研究報告(Web)　(15)　2018

ISSN：1349-1741
Evaluation Methods for Drug Side Effects Using Artificial Cell Membranes in Microfabricated Silicon Chips

但木大介, 山浦大地, FENG Xingyao, 平野愛弓, 平野愛弓

生物物理(Web)　58　(6)　2018

ISSN：1347-4219
Mechanically stable solvent-free lipid bilayers in nano- and micro-tapered apertures for reconstitution of cell-free synthesized hERG channels

Daisuke Tadaki, Daichi Yamaura, Shun Araki, Miyu Yoshida, Kohei Arata, Takeshi Ohori, Ken-ichi Ishibashi, Miki Kato, Teng Ma, Ryusuke Miyata, Yuzuru Tozawa, Hideaki Yamamoto, Michio Niwano, Ayumi Hirano-Iwata

SCIENTIFIC REPORTS　7　2017/12
Publisher: NATURE PUBLISHING GROUP
DOI： 10.1038/s41598-017-17905-x 　

ISSN：2045-2322

More details Close

The self-assembled bilayer lipid membrane (BLM) is the basic component of the cell membrane. The reconstitution of ion channel proteins in artificially formed BLMs represents a well-defined system for the functional analysis of ion channels and screening the effects of drugs that act on them. However, because BLMs are unstable, this limits the experimental throughput of BLM reconstitution systems. Here we report on the formation of mechanically stable solvent-free BLMs in microfabricated apertures with defined nano- and micro-tapered edge structures. The role of such nano- and micro-tapered structures on the stability of the BLMs was also investigated. Finally, this BLM system was combined with a cell-free synthesized human ether-alpha-go-go-related gene channel, a cardiac potassium channel whose relation to arrhythmic side effects following drug treatment is well recognized. Such stable BLMs as these, when combined with a cell-free system, represent a potential platform for screening the effects of drugs that act on various ion-channel genotypes.
Charge transport properties of bulk-heterojunction organic solar cells investigated by displacement current measurement technique

Teng Ma, Jinyu Zhang, Daisuke Tadaki, Yasuo Kimura, Ayumi Hirano-Iwata, Michio Niwano

ORGANIC ELECTRONICS　51　269-276　2017/12
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.orgel.2017.09.020 　

ISSN：1566-1199

eISSN：1878-5530

More details Close

We have investigated charge transport properties of bulk-heterojunction (BH) solar cells in which P3HT (Poly(3-hexylthiophene)) and PCBM ([6,6]-phenyl-C-61-butyric acid methyl ester) are used as the active layer, by using the displacement current measurement (DCM) method. In order to investigate the charge transport properties of the BH solar cells, we fabricated a dedicated device that consists of P3HT and PCBM, and used the DCM method to measure the charge distribution of the devices with different composition ratios of P3HT and PCBM. DCM data suggested that a BH film with 50 wt% of PCBM exhibits a preferable charge transport property suited for BH solar cells. We confirmed that the DCM results are consistent with the measured performance of the BH solar cells, indicating that the DCM method is a simple and effective method for optimizing the structure of BH solar cells as well as other electronic devices composed of binary materials. (C) 2017 Elsevier B.V. All rights reserved.
Formation of Cell Membrane Component Domains in Artificial Lipid Bilayer

Ryugo Tero, Kohei Fukumoto, Toshinori Motegi, Miyu Yoshida, Michio Niwano, Ayumi Hirano-Iwata

SCIENTIFIC REPORTS　7　2017/12
Publisher: NATURE PUBLISHING GROUP
DOI： 10.1038/s41598-017-18242-9 　

ISSN：2045-2322

More details Close

The lipid bilayer environment around membrane proteins strongly affects their structure and functions. Here, we aimed to study the fusion of proteoliposomes (PLs) derived from cultured cells with an artificial lipid bilayer membrane and the distribution of the PL components after the fusion. PLs, which were extracted as a crude membrane fraction from Chinese hamster ovary (CHO) cells, formed isolated domains in a supported lipid bilayer (SLB), comprising phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cholesterol (Chol), after the fusion. Observation with a fluorescence microscope and an atomic force microscope showed that the membrane fusion occurred selectively at microdomains in the PC + PE + Chol-SLB, and that almost all the components of the PL were retained in the domain. PLs derived from human embryonic kidney 293 (HEK) cells also formed isolated domains in the PC + PE + Chol-SLB, but their fusion kinetics was different from that of the CHO-PLs. We attempted to explain the mechanism of the PL-SLB fusion and the difference between CHO- and HEK-PLs, based on a kinetic model. The domains that contained the whole cell membrane components provided environments similar to that of natural cell membranes, and were thus effective for studying membrane proteins using artificial lipid bilayer membranes.
モジュール構造型神経回路モデルにおける同期活動のメカニズム

守谷哲, 山本英明, 井手克哉, 秋間学尚, 平野愛弓, 庭野道夫, 久保田繁, 佐藤茂雄

信学技報　117　(325)　19-23　2017/11
Publisher: 電子情報通信学会
ISSN：0913-5685
Response characteristics of hydrogen gas sensor with porous piezoelectric poly(vinylidene fluoride) film

Yuji Imai, Daisuke Tadaki, Teng Ma, Yasuo Kimura, Ayumi Hirano-Iwata, Michio Niwano

SENSORS AND ACTUATORS B-CHEMICAL　247　479-489　2017/08
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2017.03.001 　

ISSN：0925-4005

More details Close

Previously, we have proposed a new type of organic hydrogen gas sensor in which a beta-phase poly(vinylidene fluoride) (PVDF) film is coated with thin films of palladium (Pd) on both sides. Volume expansion of the Pd thin film caused by uptake of hydrogen is monitored by a capacitance change of the piezoelectric PVDF thin film. The beta-phase PVDF film was synthesized from alpha-phase PVDF powder by using a wet process that we developed. In this study, we have examined the microscopic structure of the alpha-phase PVDF films and investigated the response characteristics of the sensors: response at hydrogen exposure, detection sensitivity, recovery time and effect of humidity. We find that the PVDF film has the porous structure consisting of micro-scaled grains of PVDF and demonstrates that the response characteristics depend on the structure of the PVDF films. We propose a simple simulation model to get insight into the observed response characteristics. In the model, it is assumed that PVDF micro-grains expand and shrink one by one while exposing to hydrogen and air (or oxygen), respectively. The simulation explains the basic response characteristics of the sensor. (C) 2017 Elsevier B.V. All rights reserved.
Fabrication of resistively-coupled single-electron device using an array of gold nanoparticles

Tran Thi Thu Huong, Kazuhiko Matsumoto, Masataka Moriya, Hiroshi Shimada, Yasuo Kimura, Ayumi Hirano-Iwata, Yoshinao Mizugaki

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING　123　(8)　2017/08
Publisher: SPRINGER
DOI： 10.1007/s00339-017-1171-3 　

ISSN：0947-8396

eISSN：1432-0630

More details Close

We demonstrated one type of single-electron device that exhibited electrical characteristics similar to those of resistively-coupled SE transistor (R-SET) at 77 K and room temperature (287 K). Three Au electrodes on an oxidized Si chip served as drain, source, and gate electrodes were formed using electron-beam lithography and evaporation techniques. A narrow (70-nm-wide) gate electrode was patterned using thermal evaporation, whereas wide (800-nm-wide) drain and source electrodes were made using shadow evaporation. Subsequently, aqueous solution of citric acid and 15-nm-diameter gold nanoparticles (Au NPs) and toluene solution of 3-nm-diameter Au NPs chemisorbed via decanethiol were dropped on the chip to make the connections between the electrodes. Current-voltage characteristics between the drain and source electrodes exhibited Coulomb blockade (CB) at both 77 and 287 K. Dependence of the CB region on the gate voltage was similar to that of an R-SET. Simulation results of the model based on the scanning electron microscopy image of the device could reproduce the characteristics like the R-SET.
Modularity-dependent modulation of synchronized bursting activity in cultured neuronal network models

Satoshi Moriya, Hideaki Yamamoto, Hisanao Akima, Ayumi Hirano-Iwata, Michio Niwano, Shigeru Kubota, Shigeo Sato

Proceedings of the International Joint Conference on Neural Networks　2017-　1163-1168　2017/06/30
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/IJCNN.2017.7965983 　

More details Close

In a dissociated culture, neuronal networks spontaneously generate highly stereotypical activity characterized by synchronous bursting. With recent advancements in microfabrication technology, the topologies of cultured neuronal networks can now be engineered to have, e.g., the modular connectivity that is often found in vivo. In this paper, we construct networks of leaky integrate-and-fire neurons to theoretically investigate the effect of modular connectivity on the synchronous bursting activity of cultured neuronal networks. Modular network models are created by defining the number of modules and changing the connection formation probability within a given module, while maintaining a constant connection density. We find that the synchronized bursting frequencies in networks with the same numbers of neurons and connections are solely dependent on their modularity. We also investigate the mechanism behind the network-to-network variation of the activity in random networks, finding that local measures, such as the neuron in-degree and the self-connection, are the important factors. Out results indicate an economic advantage for networks bearing a modular structure and provides a graph-theoretical description of this mechanism.
人工脂質二重膜系への細胞膜成分の融合と観察 (M&BE研究会有機分子・バイオエレクトロニクスの最新動向と応用展開)

手老龍吾, 平野愛弓, 庭野道夫

Molecular electronics and bioelectronics = 応用物理学会,有機分子・バイオエレクトロニクス分科会会誌　28　(2)　97-100　2017/05
Publisher: 応用物理学会有機分子・バイオエレクトロニクス分科会
ISSN：2423-8805
Fabrication of Au-Nanoparticle-Embedded Lipid Bilayer Membranes Supported on Solid Substrates

Naotoshi Sakaguchi, Yasuo Kimura, Ayumi Hirano-Iwata, Toshio Ogino

JOURNAL OF PHYSICAL CHEMISTRY B　121　(17)　4474-4481　2017/05
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/acs.jpcb.7b00500 　

ISSN：1520-6106

More details Close

We fabricated gold nanoparticle (Au-NP) embedded supported lipid bilayers (SLBs) by two methods. In the vesicle vesicle fusion method, vesicles with hydrophobized Au-NPs are ruptured and fused on SiO2/Si substrates. In the vesicle-membrane fusion method, SLBs without Au-NPs were preformed on the substrate and then vesicles with Au-NPs were fused into the preformed membranes. In the former method, Au-NP incorporation into the SLBs was observed as an increase in the membrane thickness in atomic force microscopy (AFM) images and directly observed by transmission electron microscopy. In the latter method, fusion of vesicles into the preformed membranes was confirmed by the fluorescent color change in the preformed membranes, and Au-NP incorporation was also confirmed by an increase in the membrane thickness in the AFM images. Key techniques for the successful vesicle-membrane fusion are hydrophobization of Au-NPs, approach control of vesicles by mixing the charged lipids, and destabilization of the lipid bilayers by adding lipids with a small polar headgroup.
Solution-processed perovskite film for photovoltaic applications (電子デバイス)

Ma Teng, Tadaki Daisuke, Niwano Michio, Hirano-Iwata Ayumi

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　117　(6)　9-11　2017/04/20
Publisher: 電子情報通信学会
ISSN：0913-5685
Orientation and Distribution of Ion Channels Reconstructed in Supported Lipid Bilayers

117　(6)　37-40　2017/04
Publisher: 電子情報通信学会
ISSN：0913-5685
半導体微細加工に基づく薬物副作用センサの開発

平野愛弓, 但木大介, 山浦大地, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫

信学技報　117　(6)　33-35　2017/04
Publisher: 電子情報通信学会
ISSN：0913-5685
自己組織化単分子膜による自立型脂質二分子膜の膜特性制御

山浦大地, 但木大介, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫, 平野愛弓

信学技報　117　(6)　41-42　2017/04

ISSN：0913-5685
安定な人工脂質二分子膜形成のためのテーパー構造を有した微細孔をもつ半導体シリコンチップの作製

但木大介, 山浦大地, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫, 平野愛弓

信学技報　117　(6)　43-45　2017/04
Publisher: 電子情報通信学会
ISSN：0913-5685
Gate-tuned negative differential resistance observed at room temperature in an array of gold nanoparticles

Tran Thi Thu Huong, Kazuhiko Matsumoto, Masataka Moriya, Hiroshi Shimada, Yasuo Kimura, Ayumi Hirano-Iwata, Yoshinao Mizugaki

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING　123　(4)　2017/04
Publisher: SPRINGER
DOI： 10.1007/s00339-017-0891-8 　

ISSN：0947-8396

eISSN：1432-0630

More details Close

We fabricated a single-electron (SE) device using gold nanoparticles (Au NPs). Drain, source, and gate electrodes on a SiO2/Si substrate were formed using electron beam lithography (EBL) and thermal evaporation of Au. Subsequently, solutions of 3-nm-diameter and 5-nm-diameter Au NPs were dropped on the device to make current paths through Au NPs among the electrodes. Measurements of the device exhibited negative differential resistance (NDR) in the current-voltage characteristics between the drain and source electrodes at room temperature (298 K). The NDR behavior was tuned by applying a gate voltage.
Variation in spontaneous activity patterns in modular neuronal network models

116　(521)　133-136　2017/03/13
Publisher: 電子情報通信学会
ISSN：0913-5685
Functional integration of human ion channels in artificially formed bilayer lipid membranes

Hirano-Iwata Ayumi, Tadaki Daisuke, Yamaura Daichi, Araki Shun, Yoshida Miyu, Arata Kohei, Ohori Takeshi, Yamamoto Hideaki, Niwano Michio

JSAP Annual Meetings Extended Abstracts　2017.1　228-228　2017/03/01
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2017.1.0_228 　

eISSN：2436-7613
Label-free detection of DNA molecules moving in micro -fluidic channels by infrared absorption spectroscopy

Tomoyuki Miyoshi, Ken-ichi Ishibashi, Koichiro Miyamoto, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

SENSORS AND ACTUATORS B-CHEMICAL　238　917-922　2017/02
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2016.07.003 　

ISSN：0925-4005

More details Close

Infrared absorption spectroscopy (IRAS) in a multiple internal reflection (MIR) geometry is integrated with silicon-based micro-fluidic channels to allow detection and separation of DNA molecules in the micro-channels. The micro-channels were fabricated on a Si MIR-prism using the conventional silicon lithographic techniques. In the present method we can probe solution-phase biomolecular species through IR spectral profiles of those biomolecules, allowing us to detect and separate biomolecules without fluorescence labeling. The applicability of this approach is demonstrated with a representative test case: transport of single-stranded DNA molecules (oligonucleotides) in the micro-fluidic channels. (C) 2016 Elsevier B.V. All rights reserved.
Fabrication and Characterization of High-Quality Perovskite Films with Large Crystal Grains

Teng Ma, Qiwu Zhang, Daisuke Tadaki, Ayumi Hirano-Iwata, Michio Niwano

JOURNAL OF PHYSICAL CHEMISTRY LETTERS　8　(4)　720-726　2017/02
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/acs.jpclett.6b03037 　

ISSN：1948-7185

More details Close

Solution-processable organometal perovskite materials have been widely used in various kinds of devices. In these devices, the perovskite materials normally act as active layers. Grain boundaries and structural disorder in the perovskite layer would interfere the charge transport and increase recombination probability. Here we proposed a novel fabrication method to dramatically increase the crystal size by more than 20 times as compared with previously reported values. Exceptional structural order in the large crystals is illustrated by nanoscale surface morphology and a simple recrystallization method. Because of reduced grain boundaries and increased crystal order in perovskite layers, the lateral charge transport is significantly improved, as demonstrated by conductive atomic-force microscopy and performance of photodetectors. This deposition technology paves the way for future high-performance devices based on perovskite thin films.
脂質二分子膜に対する多方向電気特性評価用シリコンチップの作製

大堀健, 平野愛弓, 平野愛弓, 但木大介, 山浦大地, 荒木駿, 吉田美優, 荒田航平, 山本英明, 庭野道夫

応用物理学会春季学術講演会講演予稿集(CD-ROM)　64th　2017
半導体シリコンチップ上に作製された微細孔における安定な人工脂質二分子膜形成のためのエッジ構造の最適化

但木大介, 平野愛弓, 平野愛弓, 山浦大地, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫

応用物理学会春季学術講演会講演予稿集(CD-ROM)　64th　2017
PVDFフィルム水素ガスセンサの検知特性に及ぼす湿度の影響

今井裕司, 但木大介, MA Teng, 木村康男, 平野愛弓, 平野愛弓, 庭野道夫, 庭野道夫

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　78th　2017
局所陽極酸化によるアルミニウムナノワイヤの形成

福元隆弘, 守屋雅隆, 水柿義直, 但木大介, TENG Ma, 平野愛弓, 庭野道夫, 木村康男

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　78th　2017
PCBM包埋脂質二分子膜への光照射における電流応答

出口貴史, 馬騰, 鹿又建作, 山浦大地, 但木大介, 廣瀬文彦, 平野愛弓, 平野愛弓

応用物理学会東北支部学術講演会講演予稿集(Web)　72nd　2017
金属細線を包埋したPVDF圧力センサの作製

山宮慎, 但木大介, 馬騰, 今井裕司, 平野愛弓, 平野愛弓, 庭野道夫

応用物理学会東北支部学術講演会講演予稿集(Web)　72nd　2017
マルチウェル型チャンバーによる高効率薬物副作用検査系の構築

山浦大地, 宮田隆典, 荒木駿, 但木大介, 山本英明, 平野愛弓, 平野愛弓

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　78th　2017
支持体表面修飾による自立型脂質二重膜の安定性向上

山浦大地, 但木大介, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 荻野俊郎, 庭野道夫, 平野愛弓, 平野愛弓

応用物理学会春季学術講演会講演予稿集(CD-ROM)　64th　2017
微細加工シリコンチップにおける脂質二分子膜中のイオンチャネル電流計測

荒田航平, 平野愛弓, 平野愛弓, 但木大介, 山浦大地, 荒木駿, 吉田美優, 大堀健, 山本英明, 庭野道夫

応用物理学会春季学術講演会講演予稿集(CD-ROM)　64th　2017
Fabrication and Characterization of Front-Illuminated Dye-Sensitized Solar Cells with Anodic Titanium Oxide Nanotubes

Ryota Kojima, Yasuo Kimura, Teng Ma, Ken-ichi Ishibashi, Daisuke Tadaki, Richard A. Rosenberg, Ayumi Hirano-Iwata, Michio Niwano

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　164　(2)　H78-H84　2017
Publisher: ELECTROCHEMICAL SOC INC
DOI： 10.1149/2.1031702jes 　

ISSN：0013-4651

eISSN：1945-7111

More details Close

We have fabricated front-side illuminated dye-sensitized solar cells (DSSCs) with a thin film of vertically oriented TiO2 nanotubes used as the negative electrode. The TiO2 nanotube film was formed by anodizing a metallic titanium thin film that was deposited on a transparent conductive oxide (TCO) layer with an intermediate, protective TiO2 layer. We characterized the structural and electronic properties of the formed TiO2 nanotube films. Titanium tetrachloride (TiCl4) treatment was applied on the TiO2 nanotube film to improve the performance of the DSSCs. We have investigated effects of TiCl4 treatment on the solar cell parameters of the DSSCs: short-circuit current density (I-SC), open-circuit voltage (V-oc), ideal factor (n), series resistance (R-s) and shunt resistance (R-sh). The parameters have been derived by analyzing measured I-V characteristic of the DSSCs on the basis of the method we have previously proposed. We demonstrate that the performance of the DSSCs is improved by TiCl4 treatment. We discuss the effects of TiCl4 treatment on the performance on the basis of the derived cell parameters. (C) 2016 The Electrochemical Society. All rights reserved.
Nanostructure Fabrication through a Microwire of Local Anodization

Takahiro Fukumoto, Yasuo Kimura, Toshiro Ogino, Masataka Moriya, Yoshinao Mizugaki, Daisuke Tadaki, Ma Teng, Ayumi Hirano-Iwata, Michio Niwano

2017 IEEE INTERNATIONAL MEETING FOR FUTURE OF ELECTRON DEVICES, KANSAI (IMFEDK)　60-61　2017
Publisher: IEEE
DOI： 10.1109/IMFEDK.2017.7998042 　

More details Close

An aluminum microwire was locally anodized to form a nanowire with triangular cross section. Nanostructure formed through local anodization depended strongly on a cross sectional shape of a microwire before anodization. The width of the nanowire was controlled by the ratio of voltage between edges of locally anodized area to anodization current. This indicates that local anodization has the potential to fabricate of nanostructures for nanodevices.
Investigation of network structure and synchronous activity in modularly-structured neuronal network models

116　(313)　33-38　2016/11/18
Publisher: 電子情報通信学会
ISSN：0913-5685
Reconstitution of human ion channels in lipid bilayers formed in microfabricated apertures

Hirano-Iwata Ayumi, Yoshida Miyu, Araki Shun, Tadaki Daisuke, Ishibashi Kenichi, Arata Kohei, Takeshi Ohori, Yamamoto Hideaki, Michio Niwano

JSAP Annual Meetings Extended Abstracts　2016.2　133-133　2016/09/01
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2016.2.0_133 　

eISSN：2436-7613
Fabrication of single-electron devices using dispersed nanoparticles and fitting experimental results to values calculated based on percolation model

Masataka Moriya, Tran Thi Thu Huong, Kazuhiko Matsumoto, Hiroshi Shimada, Yasuo Kimura, Ayumi Hirano-Iwata, Yoshinao Mizugaki

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING　122　(8)　2016/08
Publisher: SPRINGER
DOI： 10.1007/s00339-016-0285-3 　

ISSN：0947-8396

eISSN：1432-0630

More details Close

We calculated the connection probability, P-C, between electrodes on the basis of the triangular lattice percolation model for investigating the effect of distance variation between electrodes and the electrode width on fabricated capacitively coupled single-electron transistors. Single-electron devices were fabricated via the dispersion of gold nanoparticles (NPs). The NPs were dispersed via the repeated dropping of an NP solution onto a chip. The experimental results were fitted to the calculated values, and the fitting parameters were compared with the occupation probability, P-O, which was estimated for one drop of the NP solution. On the basis of curves of the drain current versus the drain-source voltage (I-D-V-DS) measured at 77 K, the current was suppressed at approximately 0 V.
Live-Cell, Label-Free Identification of GABAergic and Non-GABAergic Neurons in Primary Cortical Cultures Using Micropatterned Surface

Sho Kono, Hideaki Yamamoto, Takatoshi Kushida, Ayumi Hirano-Iwata, Michio Niwano, Takashi Tanii

PLOS ONE　11　(8)　2016/08
Publisher: PUBLIC LIBRARY SCIENCE
DOI： 10.1371/journal.pone.0160987 　

ISSN：1932-6203

More details Close

Excitatory and inhibitory neurons have distinct roles in cortical dynamics. Here we present a novel method for identifying inhibitory GABAergic neurons from non-GABAergic neurons, which are mostly excitatory glutamatergic neurons, in primary cortical cultures. This was achieved using an asymmetrically designed micropattern that directs an axonal process to the longest pathway. In the current work, we first modified the micropattern geometry to improve cell viability and then studied the axon length from 2 to 7 days in vitro (DIV). The cell types of neurons were evaluated retrospectively based on immunoreactivity against GAD67, a marker for inhibitory GABAergic neurons. We found that axons of non-GABAergic neurons grow significantly longer than those of GABAergic neurons in the early stages of development. The optimal threshold for identifying GABAergic and non-GABAergic neurons was evaluated to be 110 mu m at 6 DIV. The method does not require any fluorescence labelling and can be carried out on live cells. The accuracy of identification was 98.2%. We confirmed that the high accuracy was due to the use of a micropattern, which standardized the development of cultured neurons. The method promises to be beneficial both for engineering neuronal networks in vitro and for basic cellular neuroscience research.
Unidirectional signal propagation in primary neurons micropatterned at a single-cell resolution

H. Yamamoto, R. Matsumura, H. Takaoki, S. Katsurabayashi, A. Hirano-Iwata, M. Niwano

APPLIED PHYSICS LETTERS　109　(4)　2016/07
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4959836 　

ISSN：0003-6951

eISSN：1077-3118

More details Close

The structure and connectivity of cultured neuronal networks can be controlled by using micropatterned surfaces. Here, we demonstrate that the direction of signal propagation can be precisely controlled at a single-cell resolution by growing primary neurons on micropatterns. To achieve this, we first examined the process by which axons develop and how synapses form in micropatterned primary neurons using immunocytochemistry. By aligning asymmetric micropatterns with a marginal gap, it was possible to pattern primary neurons with a directed polarization axis at the single-cell level. We then examined how synapses develop on micropatterned hippocampal neurons. Three types of micropatterns with different numbers of short paths for dendrite growth were compared. A normal development in synapse density was observed when micropatterns with three or more short paths were used. Finally, we performed double patch clamp recordings on micropatterned neurons to confirm that these synapses are indeed functional, and that the neuronal signal is transmitted unidirectionally in the intended orientation. This work provides a practical guideline for patterning single neurons to design functional neuronal networks in vitro with the direction of signal propagation being controlled. Published by AIP Publishing.
神経回路の同期的活動に対するモジュール構造の影響に関する計算論的研究

守谷哲, 山本英明, 秋間学尚, 平野愛弓, 庭野道夫, 久保田繁, 佐藤茂雄

信学技報　116　(120)　217-222　2016/06/28
Two kinds of single electron devices fabricated by dispersion of gold nano particles with different diameter

116　(14)　21-26　2016/04/21
Publisher: 電子情報通信学会
ISSN：0913-5685
Characterization of bio-materials using their immobilization on solid substrates

116　(14)　9-12　2016/04/21
Publisher: 電子情報通信学会
ISSN：0913-5685
Controlled growth of perovskite crystals for photovoltaic applications (電子デバイス)

Ma Teng, TADAKI Daisuke, HIRANO-IWATA Ayumi, NIWANO Michio

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　116　(14)　27-29　2016/04/21
Publisher: 電子情報通信学会
ISSN：0913-5685
Fabrication and characterization of p(+)-i-p(+) type organic thin film transistors with electrodes of highly doped polymer

Daisuke Tadaki, Teng Ma, Jinyu Zhang, Shohei Iino, Ayumi Hirano-Iwata, Yasuo Kimura, Richard A. Rosenberg, Michio Niwano

JOURNAL OF APPLIED PHYSICS　119　(15)　2016/04
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4946888 　

ISSN：0021-8979

eISSN：1089-7550

More details Close

Organic thin film transistors (OTFTs) have been explored because of their advantageous features such as light-weight, flexible, and large-area. For more practical application of organic electronic devices, it is very important to realize OTFTs that are composed only of organic materials. In this paper, we have fabricated p(+)-i-p(+) type of OTFTs in which an intrinsic (i) regioregular poly (3-hexylthiophene) (P3HT) layer is used as the active layer and highly doped p-type (p(+)) P3HT is used as the source and drain electrodes. The 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F-4-TCNQ) was used as the p-type dopant. A fabricating method of p(+)-i-p(+) OTFTs has been developed by using SiO2 and aluminum films as capping layers for micro-scaled patterning of the p(+)-P3HT electrodes. The characteristics of the OTFTs were examined using the photoelectron spectroscopy and electrical measurements. We demonstrated that the fabricated p(+)-i-p(+) OTFTs work with carrier injection through a built-in potential at p(+)/i interfaces. We found that the p(+)-i-p(+) OTFTs exhibit better FET characteristics than the conventional P3HT-OTFT with metal (Au) electrodes, indicating that the influence of a carrier injection barrier at the interface between the electrode and the active layer was suppressed by replacing the metal electrodes with p(+)-P3HT layers. Published by AIP Publishing.
Interaction of plasma-generated water cluster ions with chemically-modified Si surfaces investigated by infrared absorption spectroscopy

Ayumi Hirano-Iwata, Ryosuke Matsumura, Teng Ma, Yasuo Kimura, Michio Niwano, Kazuo Nishikawa

AIP ADVANCES　6　(3)　2016/03
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.4944902 　

ISSN：2158-3226

More details Close

We have investigated the interaction of water cluster ions generated by discharge plasma, with chemically modified Si surfaces using infrared absorption spectroscopy in the multiple internal reflection geometry. We observe that water cluster ions readily adsorb on SiO2-covered Si surfaces to form water droplets. We demonstrate that positively-and negatively-charged cluster ions adsorb on the SiO2-covered Si surface in different manners, indicating ionic interaction of the water droplets with the negatively-charged SiO2 surface. Water droplets formed on the protein- coated surface rupture the amide bond of the proteins, suggesting the function of protein decomposition of water cluster ions. (c) 2016 Author(s).
Identification and molecular observation of reconstituted hERG channel in support lipid bilayer membrane

Fukumoto Kohei, Yoshida Miyu, Hirano-Iwata Ayumi, Niwano Michio, Tero Ryugo

Abstract of annual meeting of the Surface Science of Japan　36　151-151　2016
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.36.0_151 　
金属細線を包埋したPVDF薄膜圧力センサ

安部良平, 但木大介, 但木大介, MA Teng, 今井裕司, 平野愛弓, 平野愛弓, 庭野道夫

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　77th　2016
Ag細線を包埋したPVDF薄膜圧力センサ

安部良平, 但木大介, 但木大介, MA Teng, 今井裕司, 平野愛弓, 平野愛弓, 庭野道夫

真空に関する連合講演会講演予稿集　57th　2016
ナノテーパー構造に基づく人工細胞膜の構築

荒木駿, 平野愛弓, 但木大介, 石橋健一, 山本英明, 庭野道夫, 庭野道夫

日本表面科学会東北・北海道支部講演会講演予稿集　2015　2016
微細加工シリコンチップにおけるナノエッジ構造と人工脂質二分子膜形成

荒田航平, 荒田航平, 平野愛弓, 平野愛弓, 石橋健一, 石橋健一, 但木大介, 但木大介, 荒木駿, 荒木駿, 吉田美優, 吉田美優, 山本英明, 山本英明, 庭野道夫, 庭野道夫, 庭野道夫

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　77th　2016
人工脂質二分子膜形成のための微細孔を有する半導体シリコンチップの作製プロセスの改善

但木大介, 平野愛弓, 石橋健一, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　77th　2016
半導体微細加工を用いた人工細胞膜アレイの開発

荒木駿, 平野愛弓, 宮田隆典, 但木大介, 石橋健一, 山本英明, 庭野道夫, 庭野道夫

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　77th　2016
自己組織化単分子膜修飾による自立型脂質二分子膜の安定性の制御

山浦大地, 但木大介, 荒木駿, 荒田航平, 吉田美優, 荻野俊郎, 庭野道夫, 平野愛弓

真空に関する連合講演会講演予稿集　57th　2016
半導体微細加工を用いた人工細胞膜アレイの開発

荒木駿, 平野愛弓, 宮田隆典, 但木大介, 石橋健一, 山本英明, 庭野道夫, 庭野道夫

真空に関する連合講演会講演予稿集　57th　2016
微細加工シリコン基板に基づく脂質二分子膜へのヒトイオンチャネル機能の再構成

吉田美優, 平野愛弓, 山本英明, 山本英明, 但木大介, 庭野道夫, 庭野道夫

真空に関する連合講演会講演予稿集　57th　2016
Fabrication of high temperature capacitively-and resistively-coupled single electron transistors using gold nanoparticles

H. T. T. Tran, K. Matsumoto, M. Moriya, H. Shimada, Y. Kimura, A. Hirano-Iwata, Y. Mizugaki

2016 IEEE 16TH INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY (IEEE-NANO)　131-134　2016
Publisher: IEEE
DOI： 10.1109/NANO.2016.7751353 　

More details Close

We fabricated single electron transistors (SETs) by using gold nanoparticles as their islands. With a simple method of the fabrication, characteristics of capacitively-and resistively-coupled SETs (C-SETs and R-SETs) were achieved at 77 K and room temperature.
Biosensing by in situ infrared spectroscopy

Michio Niwano, Ayumi Hirano-Iwata

Bunseki Kagaku　64　(11)　793-800　2015/12/09
Publisher: Japan Society for Analytical Chemistry
DOI： 10.2116/bunsekikagaku.64.793 　

ISSN：0525-1931

More details Close

We are investigating reactions at Si surfaces and interfaces using infrared spectroscopy in the multiple internal reflection geometry (MIR-IRAS). This technique, in which infrared light beams penetrate a Si crystal wafer internally while reflecting many times, enables us to monitor surface reactions with a quite high surface sensitivity. Since Si surfaces can be observed from inside, we can monitor chemical processes at Si surfaces under various environments. In this review, our MIR-IRAS approaches for the label-free detection of biomolecular interactions are presented. In our MIR-IRAS method, by analyzing IR absorption signals we can detect any structural changes induced by the biomolecular interactions. MIR-IRAS is applicable to in situ real-time monitoring of versatile samples including DNA, proteins, and living cells, regardless of the molecular size and state of the samples.
位相振動子がつくる複雑ネットワークにおける同期状態の解析

清水ファビオアキラ, 山本英明, 千田雄大, 平野愛弓, 久保田繁, 庭野道夫

信学技報　115　(318)　1-5　2015/11/13
Publisher: 電子情報通信学会
ISSN：0913-5685
積分発火型ニューロン回路におけるスモールワールド構造と同期の関係

千田雄大, 山本英明, 平野愛弓, 久保田繁, 庭野道夫

信学技報　115　(318)　7-12　2015/11/13
Publisher: 電子情報通信学会
ISSN：0913-5685
Photopatterning Proteins and Cells in Aqueous Environment Using TiO2 Photocatalysis

Hideaki Yamamoto, Takanori Demura, Kohei Sekine, Sho Kono, Michio Niwano, Ayumi Hirano-Iwata, Takashi Tanii

JOVE-JOURNAL OF VISUALIZED EXPERIMENTS　2015　(104)　2015/10
Publisher: JOURNAL OF VISUALIZED EXPERIMENTS
DOI： 10.3791/53045 　

ISSN：1940-087X

More details Close

Organic contaminants adsorbed on the surface of titanium dioxide (TiO2) can be decomposed by photocatalysis under ultraviolet (UV) light. Here we describe a novel protocol employing the TiO2 photocatalysis to locally alter cell affinity of the substrate surface. For this experiment, a thin TiO2 film was sputter-coated on a glass coverslip, and the TiO2 surface was subsequently modified with an organosilane monolayer derived from octadecyltrichlorosilane (OTS), which inhibits cell adhesion. The sample was immersed in a cell culture medium, and focused UV light was irradiated to an octagonal region. When a neuronal cell line PC12 cells were plated on the sample, cells adhered only on the UV-irradiated area. We further show that this surface modification can also be performed in situ, i.e., even when cells are growing on the substrate. Proper modification of the surface required an extracellular matrix protein collagen to be present in the medium at the time of UV irradiation. The technique presented here can potentially be employed in patterning multiple cell types for constructing coculture systems or to arbitrarily manipulate cells under culture.
Molecular doping of regioregular poly(3-hexylthiophene) layers by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane investigated by infrared spectroscopy and electrical measurements

Daisuke Tadaki, Teng Ma, Jinyu Zhang, Shohei Iino, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

JAPANESE JOURNAL OF APPLIED PHYSICS　54　(9)　2015/09
Publisher: IOP PUBLISHING LTD
DOI： 10.7567/JJAP.54.091602 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

Molecular doping is a charge-transfer process intended to improve the performance of organic electronic devices such as organic transistors. We have investigated molecular doping of regioregular poly(3-hexylthiophene) (P3HT) layers by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F-4-TCNQ) using infrared absorption spectroscopy in the multiple internal reflection geometry (MIR-IRAS) and conductivity measurements. IRAS data confirm that F-4-TCNQ acts as an effective p-type dopant for P3HT; highly doped P3HT displayed an intense, broad absorption band due to polaron ("polaron band") and a high carrier (hole) density which are indicative of the charge transfer between F-4-TCNQ and P3HT. We demonstrate that the charge (hole) transferred from the dopant molecule is distributed along the P3HT polymer chain and spreads over at least 10 thiophene monomer units on the chain. From a comparison of the measured conductivity of F-4-TCNQ-doped P3HT layers with the carrier density, we show that the carrier mobility is proportional to the concentration of carriers (holes), which suggests that F-4-TCNQ doping induces the conformational change of P3HT polymer chains to enhance the mobility of holes in the films of the doped P3HTs. (C) 2015 The Japan Society of Applied Physics
CI-3-6 Functional Reconstitution of Ion Channel Proteins in Microfabricated Silicon Chips

Hirano-Iwata Ayumi, Yamamoto Hideaki, Kimura Yasuo, Niwano Michio

Proceedings of the Society Conference of IEICE　2015　(2)　"SS-52"-"SS-53"　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
Micro- and Nano-Technologies for Lipid Bilayer-Based Ion-Channel Functional Assays

Ayumi Hirano-Iwata, Yutaka Ishinari, Hideaki Yamamoto, Michio Niwano

CHEMISTRY-AN ASIAN JOURNAL　10　(6)　1266-1274　2015/06
Publisher: WILEY-V C H VERLAG GMBH
DOI： 10.1002/asia.201403391 　

ISSN：1861-4728

eISSN：1861-471X

More details Close

Ion channel proteins provide gated pores that allow ions to passively flow across cell membranes. Owing to their crucial roles in regulating transmembrane ion flow, ion channel proteins have attracted the attention of pharmaceutical investigators as drug targets for use in the studies of both therapeutics and side effects. In this review, we discuss the current technologies that are used in the formation of ion channel-integrated bilayer lipid membranes (BLMs) in microfabricated devices as a potential platform for next-generation drug screening systems. Advances in BLM fabrication methodology have allowed the preparation of BLMs in sophisticated formats, such as microfluidic, automated, and/or array systems, which can be combined with channel current recordings. A much more critical step is the integration of the target channels into BLMs. Current technologies for the functional reconstitution of ion channel proteins are presented and discussed. Finally, the remaining issues of the BLM-based methods for recording ion channel activities and their potential applications as drug screening systems are discussed.
Micro- and Nano-Technologies for Lipid Bilayer-Based Ion-Channel Functional Assays

Ayumi Hirano-Iwata, Yutaka Ishinari, Hideaki Yamamoto, Michio Niwano

CHEMISTRY-AN ASIAN JOURNAL　10　(6)　1266-1274　2015/06
Publisher: WILEY-V C H VERLAG GMBH
DOI： 10.1002/asia.201403391 　

ISSN：1861-4728

eISSN：1861-471X

More details Close

Ion channel proteins provide gated pores that allow ions to passively flow across cell membranes. Owing to their crucial roles in regulating transmembrane ion flow, ion channel proteins have attracted the attention of pharmaceutical investigators as drug targets for use in the studies of both therapeutics and side effects. In this review, we discuss the current technologies that are used in the formation of ion channel-integrated bilayer lipid membranes (BLMs) in microfabricated devices as a potential platform for next-generation drug screening systems. Advances in BLM fabrication methodology have allowed the preparation of BLMs in sophisticated formats, such as microfluidic, automated, and/or array systems, which can be combined with channel current recordings. A much more critical step is the integration of the target channels into BLMs. Current technologies for the functional reconstitution of ion channel proteins are presented and discussed. Finally, the remaining issues of the BLM-based methods for recording ion channel activities and their potential applications as drug screening systems are discussed.
The bulk and interface of organolead halide perovskite layer in highly efficient perovskite solar cells : An infrared study (電子デバイス)

Ma Teng, Hirano-Iwata Ayumi, Niwano Michio

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　115　(5)　31-33　2015/04/16
Publisher: 電子情報通信学会
ISSN：0913-5685
Nanofabrication technology through local anodization

115　(5)　71-74　2015/04/16
Publisher: 電子情報通信学会
ISSN：0913-5685
微細加工シリコン基板に基づくイオンチャネル機能の再構成

平野愛弓, 山本英明, 木村康男, 庭野道夫

信学技報　115　(5)　35-39　2015/04/09
Publisher: 電子情報通信学会
ISSN：0913-5685
赤外分光法によるナノバブルの表面洗浄効果のその場観察

齋藤栄幸, 馬騰, 山本英明, 平野愛弓, 庭野道夫

信学技報　115　(5)　47-52　2015/04/09
Membrane fusion process of proteoliposome containing human ether-a-go-go-related gene channel into supported lipid bilayer

Fukumoto Kohei, Yoshida Miyu, Hirano-Iwata Ayumi, Niwano Michio, Tero Ryugo

Abstract of annual meeting of the Surface Science of Japan　35　174-174　2015
Publisher: The Surface Science Society of Japan
DOI： 10.14886/sssj2008.35.0_174 　
Metal-supported titanium oxide nanotube micro gas sensors

KIMURA Yasuo, Tobe Tsubasa, Kimura Shota, Kojima Ryota, Hirano-Iwata Ayumi, Niwano Michio

IEICE technical report. Component parts and materials　114　(202)　79-82　2014/09/04
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN：0913-5685

More details Close

We fabricated micro gas sensors through the local anodization process. In addition, metal nanoparticles were electrochemically deposited on the sensors and the response characteristics of the sensors were controlled. These results indicate that the local anodization process and electrochemical deposition of metal nanoparticles allow integration of different micro gas sensors in characteristics.
Interference between field excitatory postsynaptic potentials and simultaneously recorded chronoamperometric L-glutamate currents in mouse hippocampal slices

Ayumi Hirano-Iwata, Ryosuke Matsumura, Ryuta Tezuka, Michio Niwano, Tim V. P. Bliss, Masao Sugawara

ELECTROCHEMISTRY COMMUNICATIONS　45　1-4　2014/08
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.elecom.2014.04.016 　

ISSN：1388-2481

eISSN：1873-1902

More details Close

Here we report on an unexpected interaction between field excitatory postsynaptic potentials (fEPSPs) and simultaneously recorded chronoamperometric L-glutamate currents based on time-resolved (200 Hz) amperometry in mouse hippocampal slices. It was found that electric stimuli and evoked fEPSPs induced an artifact on amperometric currents due to an unintentionally formed junction between the circuits of the amperometric and fEPSP measurements. The origin of the artifact was investigated using circuit simulation. To extract a faradaic signal from the observed currents, we sampled currents when the artifact decayed, i.e., 450 ms after the stimulation. The reliability of the extracted signal was examined through the manipulation of L-glutamate release probability. (C) 2014 Elsevier B.V. All rights reserved.
シリコン微細加工で創るイオンチャネルチップ

平野愛弓, 石成裕, 木村康男, 庭野道夫

表面科学　35　(8)　438-442　2014/08

DOI： 10.1380/jsssj.35.438 　
酸化チタンナノチューブ内壁面の色素分子の吸着過程の赤外分光その場観測

山田夏輝, 但木大介, 馬騰, 平野愛弓, 庭野道夫

応用物理学会東北支部学術講演会講演予稿集　69th (CD-ROM)　2014
シリコン微細加工で創るイオンチャネルチップ

平野愛弓, 石成裕, 木村康男, 庭野道夫

表面科学　2014

DOI： 10.1380/jsssj.35.438 　
Stable Lipid Bilayers Based on Micro- and Nano-Fabrication as a Platform for Recording Ion-Channel Activities

Ayumi Hirano-Iwata, Azusa Oshima, Hideki Mozumi, Yasuo Kimura, Michio Niwano

ANALYTICAL SCIENCES　28　(11)　1049-1057　2012/11
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/analsci.28.1049 　

ISSN：0910-6340

More details Close

In this review, we will discuss our recent approaches for the formation of mechanically stable bilayer lipid membranes (BLMs) by combining with BLM formation and micro- and nano-fabrication techniques. BLMs were prepared across a microaperture fabricated in silicon (Si) chips or nanoporous alumina films using a minimized amount of organic solvent. Although BLMs spanned over the porous alumina film showed better electrical properties, such as background current noise and current transient, BLMs suspended in a thin Si3N4 septum showed a much superior BLM stability. The BLMs showed tolerance to a high voltage of +/- 1 V, a membrane lifetime of >40 h, and tolerance to repetitive solution exchanges. Application to a drug screening system has been examined by using the human ether-a-go-go-related gene (hERG) potassium channel as an illustrative example. The potentiality of the present system as a platform of the high-throughput analysis for ion-channel protein is also discussed.
Mechanically stable lipid bilayers in Teflon-coated silicon chips for single-channel recordings

Azusa Oshima, Ayumi Hirano-Iwata, Tomohiro Nasu, Yasuo Kimura, Michio Niwano

Micro and Nanosystems　4　(1)　2-7　2012/06

DOI： 10.2174/1876402911204010002 　

ISSN：1876-4029 1876-4037

More details Close

We demonstrate the microfabrication of a low-noise silicon (Si) chip as a platform for suspending mechanically stable bilayer lipid membranes (BLMs). Microapertures with smoothly tapered edges were formed by isotropic etching in a silicon nitride layer deposited on a Si substrate. The surface of the Si chip was coated with insulator layers of Teflon and SiO2. The insulator coating worked to reduce the total capacitance, leading to noise reduction (1-2 pA in peak-to-peak after low-pass filtering at 1 kHz) and elimination of current transients (&lt 0.5 ms). Since the tapered edges were necessary to maintain mechanically stable BLMs, the entire chip except for the aperture was coated with the insulators. Owing to this process, the BLMs formed in the Si chips still showed high mechanical stability after coating with the insulator layers. The membranes withstood high applied voltage (±1 V) and mechanical shocks during solution exchanges. The mechanically stable BLMs having electric properties suitable for recording activities of biological channels will open up a variety of applications including high-throughput analysis of ion-channel proteins. © 2012 Bentham Science Publishers.
ナノ・マイクロ加工に基づく人工細胞膜センサの研究

平野愛弓, 大嶋梓, 木村康男, 庭野道夫

応用物理　81　(2)　143-146　2012/02
Publisher: 応用物理学会
ISSN：0369-8009
半導体加工技術による人工脂質二分子膜センサの開発

大嶋梓, 平野愛弓, 平野愛弓, 那須朋大, 木村康男, 庭野道夫, 庭野道夫

応用物理学関係連合講演会講演予稿集(CD-ROM)　59th　2012
半導体微細加工に基づく人工脂質二分子膜イオンチャネルチップの開発

平野愛弓, 平野愛弓, 大嶋梓, 茂住英輝, 木村康男, 庭野道夫, 庭野道夫

応用物理学会学術講演会講演予稿集(CD-ROM)　73rd　2012
半導体加工に基づく人工脂質二分子膜イオンチャネルアレイの開発

平野愛弓, 平野愛弓, 大嶋梓, 那須朋大, 木村康男, 庭野道夫, 庭野道夫

日本分析化学会年会講演要旨集　61st　2012
半導体加工技術を利用したイオンチャネルセンサーの開発

大嶋梓, 平野愛弓, 平野愛弓, 茂住英輝, 木村康男, 庭野道夫, 庭野道夫

日本分析化学会年会講演要旨集　61st　2012
マイクロ加工に基づく脂質二分子膜イオンチャネルセンサの開発

大嶋梓, 平野愛弓, 平野愛弓, 茂住英輝, 木村康男, 庭野道夫, 庭野道夫

応用物理学会東北支部学術講演会講演予稿集　67th　2012
半導体微細加工に基づくイオンチャネルアレイの開発

茂住英輝, 那須朋大, 平野愛弓, 平野愛弓, 大嶋梓, 木村康男, 庭野道夫, 庭野道夫

表面科学学術講演会講演要旨集　32nd　2012
Mechanically stable free-standing bilayer lipid membranes in microfabricated silicon chips

Azusa Oshima, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

Materials Research Society Symposium Proceedings　1415　93-98　2012

DOI： 10.1557/opl.2012.352 　

ISSN：0272-9172

More details Close

In this paper, we will discuss our recent approaches for improving the mechanical stability of free-standing bilayer lipid membranes (BLMs) by combining with BLM formation and microfabrication techniques. BLMs were prepared across a microaperture fabricated in a silicon (Si) chip and their mechanical stability and electric properties were investigated. BLMs suspended in a thin Si 3N 4 septum showed a dramatic improvement of BLM stability. The BLMs were resistant to voltage of ±1 V and the membrane lifetime was 15- ∼40 h with and without incorporated channels. The membrane containing gramicidin channel exhibited tolerance to repetitive solution exchanges. At first, electric properties of the BLMs, such as noise level and current transient, were necessary to be improved. However, after coating the chip with insulator layers of Teflon and SiO 2, total chip capacitance was reduced, leading to noise reduction (1-2 pA in peak-to-peak after low-pass filtering at 1 kHz) and elimination of current transients (&lt 0.5 ms). Since the vicinity of the aperture edge was remained uncoated, the BLMs formed in the Si chips still showed high mechanical stability after the insulator coatings. The mechanically stable BLMs having electric properties suitable for recording activities of biological channels will open up a variety of applications including high-throughput analysis of ion-channel proteins. © 2012 Materials Research Society.
Stable lipid bilayers based on micro- and nano-fabrication as a platform for recording ion-channel activities

Ayumi Hirano-Iwata, Azusa Oshima, Hideki Mozumi, Yasuo Kimura, Michio Niwano

Analytical Sciences　28　(11)　1049-1057　2012

DOI： 10.2116/analsci.28.1049 　

ISSN：0910-6340 1348-2246

More details Close

In this review, we will discuss our recent approaches for the formation of mechanically stable bilayer lipid membranes (BLMs) by combining with BLM formation and micro- and nano-fabrication techniques. BLMs were prepared across a microaperture fabricated in silicon (Si) chips or nanoporous alumina films using a minimized amount of organic solvent. Although BLMs spanned over the porous alumina film showed better electrical properties, such as background current noise and current transient, BLMs suspended in a thin Si3N4 septum showed a much superior BLM stability. The BLMs showed tolerance to a high voltage of ±1 V, a membrane lifetime of &gt 40 h, and tolerance to repetitive solution exchanges. Application to a drug screening system has been examined by using the human ether-a-go-go-related gene (hERG) potassium channel as an illustrative example. The potentiality of the present system as a platform of the high-throughput analysis for ion-channel protein is also discussed. © 2012 The Japan Society for Analytical Chemistry.
Mechanically stable free-standing bilayer lipid membranes in microfabricated silicon chips

Azusa Oshima, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

Materials Research Society Symposium Proceedings　1415　(mrsf11-1415)　93-98　2012

DOI： 10.1557/opl.2012.352 　

ISSN：0272-9172

More details Close

In this paper, we will discuss our recent approaches for improving the mechanical stability of free-standing bilayer lipid membranes (BLMs) by combining with BLM formation and microfabrication techniques. BLMs were prepared across a microaperture fabricated in a silicon (Si) chip and their mechanical stability and electric properties were investigated. BLMs suspended in a thin Si 3N 4 septum showed a dramatic improvement of BLM stability. The BLMs were resistant to voltage of ±1 V and the membrane lifetime was 15- ∼40 h with and without incorporated channels. The membrane containing gramicidin channel exhibited tolerance to repetitive solution exchanges. At first, electric properties of the BLMs, such as noise level and current transient, were necessary to be improved. However, after coating the chip with insulator layers of Teflon and SiO 2, total chip capacitance was reduced, leading to noise reduction (1-2 pA in peak-to-peak after low-pass filtering at 1 kHz) and elimination of current transients (&lt 0.5 ms). Since the vicinity of the aperture edge was remained uncoated, the BLMs formed in the Si chips still showed high mechanical stability after the insulator coatings. The mechanically stable BLMs having electric properties suitable for recording activities of biological channels will open up a variety of applications including high-throughput analysis of ion-channel proteins. © 2012 Materials Research Society.
In situ modification of lipid-loaded MCM-41 channels with bovine serum albumin at a planar lipid bilayer for biosensing

Keiichiro Nozawa, Azusa Oshima, Tomohiro Nasu, Atsushi Shoji, Ayumi Hirano-Iwata, Michio Niwano, Masao Sugawara

SENSORS AND ACTUATORS B-CHEMICAL　160　(1)　139-144　2011/12
Publisher: ELSEVIER SCIENCE SA
DOI： 10.1016/j.snb.2011.07.024 　

ISSN：0925-4005

More details Close

An in situ method for modifying a receptor site on mesoporous silica MCM-41 channels in planar lipid bilayers is described, in which bovine serum albumin (BSA) is covalently linked to the MCM-41 channels via head groups of lipids loaded in the nanopores. Prior to receptor modification, lipid-loaded MCM-41 channels were incorporated with lipid bilayers formed at an aperture of a Teflon film. The in situ coupling of BSA to lipid-loaded MCM-41 channels at the lipid bilayer interface was achieved by the sulfhydryl coupling method. The lipid bilayers containing BSA-modified MCM-41 exhibited channel-like currents, which were augmented in a concentration-dependent manner by the addition of anti-BSA at fM level. The in situ modification of lipid-loaded MCM-41 channels with BSA by the amine coupling technique was also investigated. The potential of the present approach for the development of channel-type biosensors is discussed in terms of modifying bilayer interfaces with bioreceptors. (C) 2011 Elsevier B.V. All rights reserved.
微細加工で創る人工細胞膜センサ―イオンチャネルチップの実現へ向けて―

平野愛弓

未来材料　11　(11)　40-44　2011/11
Publisher: エヌ・ティー・エス
ISSN：1346-0986
半導体加工に基づくイオンチャネルチップの開発

平野愛弓, 大嶋梓, 那須朋大, 青沼有紀, 木村康男, 庭野道夫

Molecular electronics and bioelectronics　22　(2)　97-100　2011/05/30
表面赤外分光法に基づく細胞分化過程の非標識観測

青沼有紀, 近藤康彦, 平野愛弓, 木村康男, 篠原康雄, 庭野道夫, 庭野道夫

応用物理学会学術講演会講演予稿集(CD-ROM)　72nd　2011
半導体加工に基づく脂質二分子膜イオンチャネルセンサの開発

大嶋梓, 平野愛弓, 那須朋大, 木村康男, 庭野道夫, 庭野道夫

応用物理学関係連合講演会講演予稿集(CD-ROM)　58th　2011
半導体微細加工に基づく脂質二分子膜イオンチャネルチップの開発

平野愛弓, 大嶋梓, 那須朋大, 木村康男, 庭野道夫, 庭野道夫

化学系学協会東北大会プログラムおよび講演予稿集　2011　2011
微細加工に基づく人工細胞膜センサ－イオンチャネルチップへの展開－

平野愛弓

化学と工業　63　(3)　234-235　2010/03

ISSN：0022-7684
表面赤外分光法を用いたミトコンドリア内ATP合成過程のリアルタイム評価

青沼有紀, 山口僚太郎, 阿部真帆, 平野愛弓, 平野愛弓, 木村康男, 篠原康雄, 庭野道夫

表面科学学術講演会講演要旨集　30th　2010
ナノ加工技術に基づく人工脂質二分子膜の安定化とそのセンサー応用

那須朋大, 大嶋梓, 平良祐, 平野愛弓, 木村康男, 庭野道夫

日本分析化学会年会講演要旨集　59th　2010
ナノ構造設計に基づく安定化脂質二分子膜センサーの開発

平野愛弓, 平野愛弓, 大嶋梓, 那須朋大, 木村康男, 庭野道夫

表面科学学術講演会講演要旨集　30th　2010
平面脂質二分子膜中のメソポーラスシリカへのレセプター修飾法

野澤桂一郎, 那須朋大, 大嶋梓, 東海林敦, 平野愛弓, 庭野道夫, 菅原正雄

日本分析化学会年会講演要旨集　59th　2010
Stable and reproducible bilayer lipid membranes based on silicon microfabrication techniques

Ayumi Hirano-Iwata, Azusa Oshima, Yasuo Kimura, Michio Niwano

Advances in Planar Lipid Bilayers and Liposomes　11　(C)　71-86　2010

DOI： 10.1016/S1554-4516(10)11005-9 　

ISSN：1554-4516

More details Close

In this chapter, we will discuss our recent approaches for improving the reproducibility and stability of free-standing bilayer lipid membranes (BLMs) by combining with BLM formation and silicon microfabrication techniques. Membrane formation by the painting method on agarose-gel-coated silicon substrate was monitored with infrared absorption spectroscopy in a multiple-internal reflection geometry. It was demonstrated that the appearance of the C=O stretching modes of phospholipid just after the lipid application can be a measure for the successful and reproducible formation of BLMs with gigaohm seal. For preparation of stable BLMs, we have fabricated a tapered aperture with nanometer-scale smoothness. Owing to this structure, the stress on lipid bilayers at the contact with the septum was minimized, leading to improved membrane stability. Tolerance of the present BLMs to repetitive solution exchanges demonstrates high mechanical stability of the membranes. Such reproducible and stable BLMs will open up variety of applications, including a high-throughput drug screening for ion channels. © 2010 Elsevier Inc.
Stable lipid bilayers based on micro- and nano-fabrication

Ayumi Hirano-Iwata, Azusa Oshima, Tomohiro Nasu, Tasuku Taira, Yasuo Kimura, Michio Niwano

SUPRAMOLECULAR CHEMISTRY　22　(7-8)　406-412　2010
Publisher: TAYLOR & FRANCIS LTD
DOI： 10.1080/10610278.2010.487564 　

ISSN：1061-0278

More details Close

In this review, we will discuss our recent approaches for improving the mechanical stability of free-standing bilayer lipid membranes (BLMs) by combining with BLM formation and micro- and nano-fabrication techniques. BLMs were prepared across a microaperture fabricated in silicon (Si) chips or nanoporous alumina films, and their mechanical stability and electric properties were investigated. BLMs spanned over the porous alumina showed background noise currents small enough for recording activities of low-conductance channels, though further stability enhancement of porous alumina films was necessary. BLMs suspended in a thin Si3N4 septum showed a dramatic improvement of BLM stability. The BLMs were resistant to a voltage of +/- 1V and the membrane lifetime was 15-43h with and without incorporated channels. The membrane containing gramicidin channel exhibited tolerance to repetitive solution exchanges, though the electric properties of the BLMs are necessary to be improved. The realisation of BLMs having both mechanical stability and proper electric properties will open up a variety of applications including highly sensitive biosensors and high-throughput drug screenings for ion channels.
In situ real-time monitoring of biomolecular interactions by using surface infrared spectroscopy

Ayumi Hirano-Iwata, Ryo-taro Yamaguchi, Ko-ichiro Miyamoto, Yasuo Kimura, Michio Niwano

JOURNAL OF APPLIED PHYSICS　105　(10)　102039-1-102039-11　2009/05
Publisher: AMER INST PHYSICS
DOI： 10.1063/1.3116611 　

ISSN：0021-8979

eISSN：1089-7550

More details Close

This paper reviews our recent approaches for in situ label-free detection of biomolecules and their interactions by using infrared absorption spectroscopy (IRAS) in the multiple internal reflection (MIR) geometry. Biomolecular interactions, such as DNA hybridization, DNA hydration, protein-protein interaction, cell growth and cell death, were characterized and monitored in situ both in D(2)O and H(2)O media. Combination of MIR-IRAS and various sensing platforms, such as Si, GaAs, porous Si, and porous amunina, was also discussed in terms of sensitivity and applicability to chip analysis. It is demonstrated that MIR-IRAS is a promising tool not only for the label-free detection of biomolecules but also for the accurate discrimination between specific and nonspecific interactions, which is critically important when we are monitoring complex and dynamic biological samples.
Applied Optics for Medicine and Biology

KIMURA Yasuo, HIRANO IWATA Ayumi

38　(4)　201-201　2009/04/10

ISSN：0389-6625
ソフトナノテクノロジーのための計測技術

藤井政俊, 平野愛弓, 山口僚太郎, 木村康男, 庭野道夫, 杉山滋, 山内武志, 吉野智之, 桑崎誠剛, 山本公子, 大谷敏郎

表面科学　30　219-228　2009/04

DOI： 10.1380/jsssj.30.219 　
Visualizing L-glutamate fluxes in acute hippocampal slices with glutamate oxidase-immobilized coverslips

Wataru Okumura, Nobukatsu Moridera, Ena Kanazawa, Atushi Shoji, Ayumi Hirano-Iwata, Masao Sugawara

ANALYTICAL BIOCHEMISTRY　385　(2)　326-333　2009/02
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI： 10.1016/j.ab.2008.10.047 　

ISSN：0003-2697

More details Close

We used a glutamate oxidase (GluOx)-immobilized glass coverslip for reducing diffusional blur and improving the temporal resolution of visualizing L-glutamate fluxes in acute brain slices. The immobilization of GluOx on an avidin modified glass coverslips was achieved by optimized the amine coupling method. The GluOx coverslip was applied to the imaging of L-glutamate fluxes in acute hippocampal slices under hypoxia and KCl stimulation. A slice from mouse brain was loaded with horseradish peroxidase (HRP) and substrate DA-64, and placed on the GluOx coverslip for stimulation. The regional distribution of hypoxia-induced L-glutamate fluxes was analyzed. The maximum flux at 3 min after the onset of hypoxia increased in the order CA1 > CA3 > DG. The time-courses of the L-glutamate fluxes at CA1 and DG were biphasic, while that at CA3 decreased monotonously. The KCl-stimulated release Of L-glutamate in the presence of the DL-TBOA uptake inhibitor was imaged. While no noticeable change was observed in the absence Of DL-TBOA, L-glutamate fluxes in the presence of the inhibitor increased in the order CA1 > CA3 > DG, reflecting the effect of uptake processes. The present approach suppressed diffusional blur of the glutamate signal and improved the temporal resolution as compared with the BSA-HRP membrane method described earlier. (C) 2008 Elsevier Inc. All rights reserved.
ナノポーラス構造を用いた人工脂質二分子膜センサの開発

平良祐, 大嶋梓, 平野愛弓, 木村康男, 庭野道夫, 庭野道夫

日本分析化学会年会講演要旨集　58th　2009
ポーラスアルミナフィルムを用いた人工脂質二分子膜イオンチャネルセンサの開発

平良祐, 青戸孝至, 大嶋梓, 平野愛弓, 木村康男, 庭野道夫, 庭野道夫

応用物理学関係連合講演会講演予稿集　56th　(3)　2009
ナノ構造を用いた自立型脂質二分子膜

平野愛弓, 大嶋梓, 青戸孝至, 平良祐, 木村康男, 庭野道夫, 庭野道夫

日本バイオマテリアル学会大会予稿集　31st　2009
ナノ構造設計を用いた脂質二分子膜の安定化とそのセンサー応用

平野愛弓, 大嶋梓, 青戸孝至, 平良祐, 木村康男, 庭野道夫, 庭野道夫

化学系学協会東北大会プログラムおよび講演予稿集　2009　2009
表面赤外分光法を用いた抗原抗体反応の非標識検出：二次構造解析による特異・非特異信号の識別

平野愛弓, 小野寺恒太, 宮本浩一郎, 片岡正俊, 篠原康雄, 木村康男, 庭野道夫

表面科学　29　(9)　558-563　2008/09
Publisher: The Surface Science Society of Japan
DOI： 10.1380/jsssj.29.558 　

ISSN：0388-5321

More details Close

This paper reviews our recent approaches for a label-free detection of protein-protein interactions which can perform simultaneous protein conformational analysis by using infrared absorption spectroscopy in the multiple internal reflection geometry (MIR-IRAS). Using this method, the target protein was detected in aqueous solution phase based on the peak height of the protein amide I and amide II bands, while discrimination of specific and nonspecific signals is made based on the secondary structure of the target protein. An antigen-antibody interaction on semiconductor surfaces was investigated as a model system, since it is well-known that antibodies largely consist of β-sheet structures. The features of our approach using MIR-IRAS combined with protein secondary structure analysis were discussed in terms of sensitivity, capability of quantitative analysis, and specific/nonspecific discrimination.
The design of molecular sensing interfaces with lipid-bilayer assemblies

Ayumi Hirano-Iwata, Michio Niwano, Masao Sugawara

TRAC-TRENDS IN ANALYTICAL CHEMISTRY　27　(6)　512-520　2008/06
Publisher: ELSEVIER SCIENCE LONDON
DOI： 10.1016/j.trac.2008.04.006 　

ISSN：0165-9936

More details Close

We describe the current status of techniques for preparing planar lipid bilayers, the fusion of sensory elements and the design of bilayer interfaces for analytical applications. Advances in bilayer fabrication have allowed preparation of lipid bilayers with membrane resistance of >1 G Omega ("gigaseal") in flow, microfluidic and array formats, which have enabled single-channel and multi-channel recording. Not only biological but also engineered channels have been adopted as sensory elements for lipid-bilayer-based biosensors. Synthetic and inorganic channels are also emerging for designing membranes for lipid-bilayer sensors. We discuss the potential of lipid bilayers containing biological, engineered or synthetic channels for the design of biosensors, including drug-screening biosensors. (C) 2008 Elsevier Ltd. All rights reserved.
In situ study of DNA attachment and hybridization at silicon surfaces by infrared absorption spectroscopy

Ken-ichi Ishibashi, Kohki Tanaka, Ayumi Hirano-Iwata, Ko-ichiro Miyamoto, Yasuo Kimura, Michio Niwano

JAPANESE JOURNAL OF APPLIED PHYSICS　47　(4)　3204-3208　2008/04
Publisher: JAPAN SOCIETY APPLIED PHYSICS
DOI： 10.1143/JJAP.47.3204 　

ISSN：0021-4922

eISSN：1347-4065

More details Close

In this study, we have investigated in situ the process of DNA immobilization and the subsequent hybridization on Si surfaces by using infrared (IR) absorption spectroscopy in the geometry of multiple internal reflection (MIR-IRAS). We use 3-aminopropyl-triethoxysilane (APTES) to functionalize Si surfaces with the amine group for DNA attachment. MIR-IRAS data, together with ab initio calculations, demonstrate that the amine-terminated surfaces are covalently coupled to thiol-modified oligonucleotides using a crosslinker of sulfo-succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SSMCC). Hybridization experiments reveal that MIR-IRAS enables us to detect DNA hybridization through IR spectral changes in the frequency region around 1685 cm(-1) where the vibrational modes of the bases appear. The present results show that MIR-IRAS is a promising tool for the label-free detection of DNA hybridization as well as the in situ (in vitro) characterization of the conformation changes of DNA molecules immobilized on Si surfaces.
表面赤外分光法を用いた脂質二分子膜形成過程のその場観察

平野愛弓, 小野寺恒太, 大嶋梓, 山口僚太郎, 木村康男, 庭野道夫, 庭野道夫

応用物理学会学術講演会講演予稿集　69th　(3)　2008
多重内部反射型赤外吸収分光による金薄膜上のDNA固定化とハイブリダイゼーションの検出

田中公貴, 平野愛弓, 木村康男, 庭野道夫

表面科学講演大会講演要旨集　27th　159　2007/11/01

DOI： 10.14886/sssj.27.0.159.0 　
Label-free detection of protein-protein interactions at the GaAs/Water interface through surface infrared spectroscopy: Discrimination between specific and nonspecific interactions by using secondary structure analysis

Kota Onodera, Ayumi Hirano-Iwata, Ko-Ichiro Miyamoto, Yasuo Kimura, Masatoshi Kataoka, Yasuo Shinohara, Michio Niwano

LANGMUIR　23　(24)　12287-12292　2007/11
Publisher: AMER CHEMICAL SOC
DOI： 10.1021/la7022192 　

ISSN：0743-7463

More details Close

Here, we propose a label-free detection of protein-protein interactions that enables simultaneous qualitative analysis of target proteins by using Fourier transform infrared (FTIR) absorption spectroscopy in multiple internal reflection geometry (MIR-FTIR). Using this method, the target proteins were detected based on the peak height of the amide I and amide II bands, while discrimination of specific and nonspecific signals is made based on the secondary structure of the analytes, which is determined through second-derivative analysis of the amide I band. As a model system, an antigen peptide was immobilized on the surface of GaAs, which was transparent to mid-infrared light, and the interaction with its antibody was examined in aqueous media. We demonstrated that the binding of the antibody to the antigen immobilized on a GaAs surface selectively gave rise to beta-sheet amide I vibrations (1639 and 1690 cm(-1)), while no structurally related signals were induced by nonspecifically adsorbed proteins. The peak height of the P-peak (1639 cm(-1)) in the amide I band linearly increased with the antiserum concentration as well as that of the amide II band. The detection limit (S/N = 3) was a 1:36 000 dilution for the amide I signal. In addition, through the use of surface-sensitive MIR-FTIR, the present sensor selectively detected the antigen-antibody interactions at the surfaces without being affected by the presence of bulk species, enabling rapid and wash-free detection. Our method provides not only rapid label-free detection of protein-protein interactions but a more accurate discrimination between specific and nonspecific interactions through the use of the secondary structure of the target proteins as a measure for the specific signals.
Development of Biosensing Methods for Extracellular Neuronal Messengers and Their Application to In Situ Detection in Acute Brain Slices

Ayumi Hirano

Bunseki Kagaku　55　(8)　535-546　2006/10/10
Publisher: The Japan Society for Analytical Chemistry
DOI： 10.2116/bunsekikagaku.55.535 　

ISSN：0525-1931

More details Close

The present paper describes the development of biosensing methods for extracellular neuronal messengers, L-glutamate and arachidonic acid, and their application to in situ detection in acute brain slices. The methods include and an L-glutamate microsensor based on the capillary action of glass capillaries, an L-glutamate imaging method based on glutamate oxidase-horseradish peroxidase (GluOx-HRP) membranes and an excised patch membrane sensor for arachidonic acid. The L-glutamate microsensor has achieved highly sensitive detection and low sampling volume, which is necessary to minimize physical and chemical perturbations to brain slices. With the GluOx-HRP membrane combined with a difference-image analysis, the time-resolved regional distribution of the L-glutamate flux in acute brain slices was visualized. An in situ sensor for arachidonic acid was developed based on the interaction between arachidonic acid and the phospholipid bilayer of excised patch membranes. The response characteristics of these biosensing methods were studied in terms of the working principle, dynamic range, sensitivity, selectivity and applicability to in situ detection in acute brain slices. © 2006 The Japan Society for Analytical Chemistry.
Receptors and enzymes for medical sensing of L-glutamate

Ayumi Hirano, Masao Sugawara

MINI-REVIEWS IN MEDICINAL CHEMISTRY　6　(10)　1091-1100　2006/10
Publisher: BENTHAM SCIENCE PUBL LTD
DOI： 10.2174/138955706778560102 　

ISSN：1389-5575

More details Close

Medical sensing systems using isolated or intact glutamate receptor (GluR) ion channels and glutamate oxidase (GluOx) are discussed for L-glutamate, one of the principal neurotransmitter in the central nervous systems of mammalian brain, and related agonists. The GluR-based sensing system used for the evaluation of signal transduction ability of GluR channels demonstrate that the agonist selectivity based on the signal transduction ability is not parallel to that of the binding assay. On the other hand, the appropriate design of the enzyme system, namely glutamate oxidase (GluOx), in combination with horseradish peroxidase (HRP), enables to real-time monitoring Of L-glutamate in vivo and in vitro and also to visualize its release in submerged, acute mouse hippocampal slices.
Autophosphorylation of alpha CaMKII is not a general requirement for NMDA receptor-dependent LTP in the adult mouse

Sam F. Cooke, Jianqun Wu, Florian Plattner, Michael Errington, Michael Rowan, Marco Peters, Ayumi Hirano, Karl D. Bradshaw, Roger Anwyl, Timothy V. P. Bliss, K. Peter Giese

JOURNAL OF PHYSIOLOGY-LONDON　574　(3)　805-818　2006/08
Publisher: WILEY-BLACKWELL
DOI： 10.1113/jphysiol.2006.111559 　

ISSN：0022-3751

More details Close

Autophosphorylation of alpha-Ca(2+)/calmodulin kinase II (alpha CaMKII) at Thr(286) is thought to be a general effector mechanism for sustaining transcription-independent long-term potentiation (LTP) at pathways where LTP is NMDA receptor-dependent. We have compared LTP at two such hippocampal pathways in mutant mice with a disabling point mutation at the Thr(286) autophosphorylation site. We find that autophosphorylation of alpha CaMKII is essential for induction of LTP at Schaffer commissural-CA1 synapses in vivo, but is not required for LTP that can be sustained over days at medial perforant path-granule cell synapses in awake mice. At these latter synapses LTP is supported by cyclic AMP-dependent signalling in the absence of alpha CaMKII signalling. Thus, the autophosphorylation of alpha CaMKII is not a general requirement for NMDA receptor-dependent LTP in the adult mouse.
Design and Application of Planar Bilayer Lipid Membranes Containing Biological Ion Channels for Chemical Sensing

Masao Sugawara, Ayumi Hirano

Advances in Planar Lipid Bilayers and Liposomes　1　(C)　221-245　2005

DOI： 10.1016/S1554-4516(05)01008-2 　

ISSN：1554-4516

More details Close

The design and application of planar bilayer lipid membranes (BLMs) with biological ion channels and related compounds allow highly sensitive and selective sensing systems for bioactive substances. The potentiality of partially purified glutamate receptor ion channels and a gramicidin channel embedded in artificial BLMs for designing new sensing systems was discussed in terms of principles, sensitivity and selectivity. The selective interaction of arachidonic acid with not only artificial bilayer membranes but also with biomembranes provided the design of a new sensing system for the detection of arachidonic acid released in mouse brain slices. The molecular design of planar BLMs with biological ion channels and related compounds provided an important tool for chemical sensing of bioactive substances and acquisition of physiologically relevant information. © 2005 Elsevier Inc. All rights reserved.
A Glass Capillary Microelectrode Based on Capillarity and Its Application to the Detection of L-Glutamate Release in Mouse Brain Slices

Ayumi Hirano, Masao Sugawara

Bunseki　652-654　2004/11
Acute effect of corticosterone on N-methyl-D-aspartate receptor-mediated Ca2+ elevation in mouse hippocampal slices

S Sato, H Osanai, T Monma, T Harada, A Hirano, M Saito, S Kawato

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS　321　(2)　510-513　2004/08
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI： 10.1016/j.bbrc.2004.06.168 　

ISSN：0006-291X

More details Close

We examined the rapid effects of corticosterone (CORT) on N-methyl-D-aspartate (NMDA) receptor-mediated Ca2+ signals in adult mouse hippocampal slices by using Ca2+ imaging technique. Application of NMDA caused a transient elevation of intracellular Ca2+ concentration followed by a decay to a plateau within 150 s. The 30 min preincubation of CORT induced a significant decrease of the peak amplitude of NMDA-induced Ca2+ elevation in the CA1 region. The rapid effect of CORT was induced at a stress-induced level (0.4-10 muM). Because the membrane non-permeable bovine serum albumin-conjugated CORT also induced a similar rapid effect, the rapid effect of CORT might be induced via putative surface CORT receptors. In contrast, CORT induced no significant effects on NMDA-induced Ca2+ elevation in the dentate gyrus. In the CA3 region, CORT effects were not evaluated, because the marked elevation of NMDA-induced Ca2+ signals was not observed there. (C) 2004 Elsevier Inc. All rights reserved.
Development and application of capillary electrochemical sensors

M Sugawara, A Hirano

BUNSEKI KAGAKU　51　(12)　1121-1133　2002/12
Publisher: JAPAN SOC ANALYTICAL CHEMISTRY
DOI： 10.2116/bunsekikagaku.51.1121 　

ISSN：0525-1931

More details Close

The present paper describes analytical aspects of electrochemical ultramicrosensors constructed using glass capillaries having a tip diameter of 0.5similar to12 mum. The constructed sensors included open capillary electrodes with the sampling ability of analytes based on electrokinetic phenomena and capillarity, membrane sensors in combination with planar bilayer lipid membranes (BLMs) and excised biomembrane sensors. The open capillary sensor had abilities of electrokinetic sampling and charge-selective detection of analyte ions. Selective detection of dopamine in a neutral solution after being transported into an inner acidic solution of the open capillary sensor was also demonstrated. The constructed capillary membrane sensors include (i) a novel sensor that mimics the mode of signal transduction displayed by G protein-linked receptors with BLMs containing receptors and a single gramicidin channel, (ii) an excised biomembrane sensor that allows the detection of arachidonic acid selectively over its metabolites and other fatty acids, and (iii) L-glutamate sensors using BLMs and biomembranes containing a glutamate receptor. The response characteristics of these capillary sensors were studied in terms of the working principle, dynamic range, sensitivity and selectivity. The application of these sensors to detection of signaling molecules in mouse brain slices was also demonstrated.
Development and application of capillary electrochemical sensors

Masao Sugawara, Ayumi Hirano

Bunseki Kagaku　51　(12)　1121-1133　2002
Publisher: Japan Society for Analytical Chemistry
DOI： 10.2116/bunsekikagaku.51.1121 　

ISSN：0525-1931

More details Close

The present paper describes analytical aspects of electrochemical ultramicrosensors constructed using glass capillaries having a tip diameter of 0.5-12 μm. The constructed sensors included open capillary electrodes with the sampling ability of analytes based on electrokinetic phenomena and capillarity, membrane sensors in combination with planar bilayer lipid membranes (BLMs) and excised biomembrane sensors. The open capillary sensor had abilities of electrokinetic sampling and charge-selective detection of analyte ions. Selective detection of dopamine in a neutral solution after being transported into an inner acidic solution of the open capillary sensor was also demonstrated. The constructed capillary membrane sensors include (i) a novel sensor that mimics the mode of signal transduction displayed by G protein-linked receptors with BLMs containing receptors and a single gramicidin channel, (ii) an excised biomembrane sensor that allows the detection of arachidonic acid selectively over its metabolites and other fatty acids, and (iii) L-glutamate sensors using BLMs and biomembranes containing a glutamate receptor. The response characteristics of these capillary sensors were studied in terms of the working principle, dynamic range, sensitivity and selectivity. The application of these sensors to detection of signaling molecules in mouse brain slices was also demonstrated.
Highly sensitive detection of abasic sites in DNA

Ayumi Hirano, Masao Sugawara

BIO INDUSTRY　19　14--23　2002
Design and application of ion-channel sensors based on biological and artificial receptors

Masao Sugawara, Ayumi Hirano, Philippe Bühlmann, Yoshio Umezawa

Bulletin of the Chemical Society of Japan　75　(2)　187-201　2002

DOI： 10.1246/bcsj.75.187 　

ISSN：0009-2673

More details Close

This paper reviews approaches to chemical sensing with receptor-modified electrodes that mimic the function of natural membranes containing biological and synthetic receptor channels. We highlight different types of ion-channel sensors, focusing on the working principle and the fundamental aspects, such as sensitivity and selectivity. It is demonstrated that biological receptors such as glutamate receptor ion channels and gramicidin, embedded in bilayer lipid membranes, have the potential as sensing elements for ion channel sensors with excellent sensitivity and selectivity. In addition, higher selectivities by improved receptor desigh, taking into account the particular advantages of interfacial analyte recognition at LB membranes and SAMs, are also shown with ion-channel sensors for antibodies, protamine, heparin, abasic DNA sites, and oligonucleotides.
Potentiometric Responses of Polymeric Liquid Membranes Based on Hydrophobic Chelating Agents to Metal Ions

Yasoo Itoh, Yoshihisa Ueda, Yoshihisa Ueda, Ayumi Hirano, Ayumi Hirano, Masao Sugawara, Masao Sugawara, Koji Tohda, Hideo Akaiwa, Yoshio Umezawa

Analytical Sciences　17　621-627　2001/12/01

DOI： 10.2116/analsci.17.621 　

ISSN：0910-6340

More details Close

The effect of hydrophobicity of acidic chelating agents as sensing materials on the potentiometric responses of polymeric liquid membranes was investigated. The chelating agents tested were 8-quinolinol (HOx), dithizone (HDz), 1-(2-pyridylazo)-2-naphthol (PAN) and their alkylated analogues, 5-octyloxymethyl-8-quinolinol (HO8Q), di(p-hexylphenyl)thiocarbazone (C6HDz), 7-pentadecyloxy-1-(2-pyridylazo)-2-naphthol (C15PAN) and a series of N-alkylcarbonyl-N-phenylhydroxylamines (CnPHA, n = 3, 6, 9, 12). The distribution coefficients between membrane solvent and water were determined to evaluate the hydrophobicity of the agents. The potential-pH profiles of the membranes containing hydrophobic chelating agents demonstrated the generation of potentiometric responses, while less hydrophobic agents gave no response. A possible model for the generation of membrane potential is proposed. The charge separation is attained by the permselective uptake of metal cations by the chelating agent anion at membrane/solution interface, where the high hydrophobicity of the agent enables the anionic or deprotonated form of the agents to remain at the membrane/solution interface.
A glass capillary ultramicroelectrode with an electrokinetic sampling ability

A. Hirano, M. Kanai, T. Nara, M. Sugawara

Analytical Sciences　17　(1)　37-43　2001

DOI： 10.2116/analsci.17.37 　

ISSN：0910-6340

More details Close

A glass capillary ultramicroelectrode (tip diameter ≅1.2 μm) having an electrokinetic sampling ability is described. It is composed of a pulled glass capillary filled with an inner solution and three internal electrodes (Pt working and counter electrodes and an Ag/AgCl reference electrode). The voltammetric response of the capillary electrode is based on electrokinetic transport of analyte ions from the sample solution into the inner solution across the conical tip. It was found that the electrophoretic migration of analytes at the conical tip is faster than electroosmotic flow, enabling electrokinetic transport of analyte ions into the inner solution of the electrode. By using [Fe(CN)6]4-and(ferrocenylmethyl)trimethylam monium (FcTMA+) ions as model analytes, differential pulse voltammetric responses of the capillary electrode were investigated in terms of tip diameter of the capillary, sampling voltage, sampling time, detection limit and selectivity. The magnitude of the response depends on the size and charge of analyte ions. With a capillary electrode having a ≅1.2-μm tip diameter, which minimizes non-selective diffusional entry of analytes, the response after 1 h sampling at +1.7 V is linearly related to [Fe(CN)6]4- concentration in the range of 0.50 - 5.0 mM with the detection limit of 30 μM. Application of a potential of the same sign as that of the analyte ion forces the analyte to move out from the electrode to the solution, enabling reuse of the same capillary electrode. The charge-selective detection of analytes with the capillary electrode is demonstrated for [Fe(CN)6]4- in the presence of FcTMA+.
A single-channel method for evaluation of very magnitudes of Ca2+ ion fluxes through ε4/ζ1 N-methyl-D-aspartate receptor channels in bilayer lipid membranes

Masaki Wakabayashi, Ayumi Hirano, Masao Sugawara, Shigeo Uchino, Sadayo Nakajima-Iijima

Journal of Pharmaceutical and Biomedical Analysis　24　(3)　453-460　2001

DOI： 10.1016/S0731-7085(00)00467-2 　

ISSN：0731-7085

More details Close

A single-channel method for evaluating agonist selectivity in terms of the very number of Ca2+ ions passed through the ε4/ζ1 N-methyl-D-aspartate (NMDA) receptor ion channel in bilayer lipid membranes (BLMs) is described. The number of Ca2+ passed through the single-channel was obtained from single-channel recordings in a medium where the primary permeant ion is Ca2+. The recombinant ε4/ζ1 NMDA channel was partially purified from Chinese hamster ovary cells expressing the channel and incorporated in BLMs formed by the tip-dip method. It was found that the ε4/ζ1 channel in BLMs is permeable to Ca2+ and Na+, but the number of Ca2+ passed through the channel is much fewer than that of Na+. The integrated Ca2+ currents induced by three typical agonists NMDA, L-glutamate and L-CCG-IV were obtained at concentration of 50 μM, where the integrated currents for all the agonists reached their saturated values. The integrated Ca2+ currents obtained are (3.1 ± 0.21) × 10-13 C/s for NMDA, (4.6 ± 0.31) × 10-13 C/s for L-glutamate and (5.7 ± 0.25) × 10-13 C/s for L-CCG-IV, respectively, suggesting that the three kinds of agonists have different efficacies to induce permeation of Ca2+. The range of the agonist selectivity thus obtained is much narrower than that of binding affinities for the NMDA receptors from rat brain. The present method is able to detect Ca2+ permeation with a detection limit of ≈ 105 Ca2+ ions/s. © 2001 Elsevier Science B.V.
Evaluation and comparison of ion permeation and agonist selectivities for N-methyl-D-aspartate receptor channels with different subunit compositions in bilayer lipid membranes based on integrated single-channel currents

A Hirano, M Wakabayashi, M Sugawara, S Uchino, S Nakajima-Iijima

ANALYTICAL BIOCHEMISTRY　283　(2)　258-265　2000/08
Publisher: ACADEMIC PRESS INC
DOI： 10.1006/abio.2000.4650 　

ISSN：0003-2697

More details Close

To quantify the ion-permeation ability of the recombinant epsilon 1-4/zeta 1 channel activated by agonists, the magnitude of agonist-induced integrated single-channel currents for the epsilon 2-4/zeta 1 N-methyl-D-aspartate (NMDA) channels in bilayer lipid membranes (BLMs) was evaluated electrochemically based on the single-channel recordings. The recombinant epsilon 2-4/zeta 1 channels were purified from Chinese hamster ovary cells expressing each channel and incorporated in BLMs formed by the tip-dip method. Three typical agonists, L-glutamate, NMDA, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (L-CCG-IV), were investigated at a concentration of 50 mu M. The magnitude of L-glutamate-induced integrated current was found to depend on the E-subunit composition and to increase in the order of epsilon 2/zeta 1 > epsilon 1/zeta 1 approximate to epsilon 4/zeta 1 > epsilon 3/zeta 1, which differs from that of the reported binding affinities (EC50) between L-glutamate and each channel type. On the other hand, the magnitude of the integrated currents induced by NMDA and L-CCG-IV did not vary among the four channel types. The order of agonist selectivity toward the epsilon 2-4/zeta 1 channels in terms of the magnitude of the integrated current was L-glutamate > L-CCG-IV approximate to NMDA for the epsilon 2/zeta 1 channel, L-CCG-IV > NMDA > L-glutamate for the epsilon 3/zeta 1 channel, and L-CCG-IV approximate to L-glutamate > NMDA for the epsilon 4/zeta 1 channel, suggesting that the agonist selectivity also depends on the E-subunit composition. The present study shows that each epsilon 1-4/zeta 1 channel has its own ability of ion permeation, i.e., its own signal transduction ability, which is not parallel to its binding ability. (C) 2000 Academic Press.
A Single-Channel Sensor for Evaluation of Very Magnitude of Ca2+ Ions Passed through ε4/ζ1 N-Methyl-D-Aspartate Receptor Channel in Bilayer Lipid Membranes.

若林正樹, 平野愛弓, 内野茂夫, 飯島貞代, 高木弦, 菅原正雄

日本化学会講演予稿集　78th　(1)　2000

ISSN：0285-7626
Fundamental studies on chemical sensing based on receptor-incorporated bilayer lipid membranes

M Sugawara, A Hirano

BUNSEKI KAGAKU　47　(12)　903-917　1998/12
Publisher: JAPAN SOC ANALYTICAL CHEM
DOI： 10.2116/bunsekikagaku.47.903 　

ISSN：0525-1931

More details Close

The present paper describes analytical aspects of receptor-incorporated bilayer lipid membranes (BLMs) sensors based on transmembrane signaling: (i) membrane potential change, (ii) membrane permeability change and (iii) active transport. The receptors used in the present study included synthetic and natural ionophores as well as bioreceptors, such as Na+, K+-ATPase, glutamate receptor ion channel and Na+/D-glucose cotransporter. The receptors were incorporated into planar BLMs formed by the folding and tip-dip methods. The membrane capacitance and current noise of the BLMs formed by both methods were also investigated. By comparing the conductance of BLMs with and without receptors, an experimental criterion for judging the successful incorporation of receptors into the BLMs was achieved. The response characteristics of the constructed BLM sensors were considered in terms of their principles, sensitivity, selectivity and amplification ability. The potentiometric responses of BLM sensors based on synthetic ionophores were significantly improved by the simultaneous incorporation of anionic sites, providing a basis for quantitative BLM sensors. The highly sensitive detection of agonists with glutamate receptor-based BLM sensors was also demonstrated. Synthetic ionophore-incorporated BLM sensors were constructed that induce analyte-triggered membrane permeability changes, attributed to permeation of primary ions as well as counter anions. The future prospects of receptor-incorporated BLM sensors were also considered.
Planar lipid bilayer membrane glutamic acid ion channel sensor. Evaluation of agonist chemoselectivity based on molecular species.

平野愛弓, 菅原正雄, 梅沢喜夫, 内野茂夫, 飯島貞代

分析化学討論会講演要旨集　59th　1998
Chemical sensing based on receptor proteins-evaluation of physiologically more relevant agonist selectivity-

Masao Sugawara, Takeaki Ozawa, Ayumi Hirano, Jun Nakanishi, Moritoshi Sato, Yoshio Umezawa

Hyomen　35　660--668　1997

Show all ︎Show first 5

Books and Other Publications 6

ブルーバックス「すごいぞ！身の回りの表面科学」

平野愛弓

2015/10/20
Advances in Planar Lipid Bilayers and Liposomes Vol.11

Ayumi Hirano-Iwata, Azusa Oshima, Yasuo Kimura, Michio Niwano

2010/10
Advances in Planar Lipid Bilayers and Liposomes Vol.1

M. Sugawara, A. Hirano

Elsevier　2005
Analytical Techniques-from science to nano/bio

Sugawara Masao, Ayumi Hirano

エヌ・ティー・エス　2004
Affinity Biosensors, Techniques and Protocols

M. Sugawara, A. Hirano, Y. Umezawa

Humana Press　1998
Biological supersensors

Ayumi Hirano, Takeaki Ozawa, Masao Sugawara, Yoshio Umezawa

Kyoritsu　1997

Show all Show first 5

Presentations 285

Modular Topology Enhances Reservoir Computing Performance in Biological Neuronal Networks

Sumi Takuma, Yamamoto Hideaki, Katori Yuichi, Ito Koki, Sato Shigeo, Hirano-Iwata Ayumi

IEICE Proceeding Series　2023/09/21

More details Close

Reservoir computing is a machine learning paradigm that employs high-dimensional dynamical systems for information processing. Although biological neuronal networks (BNNs) have been utilized to implement reservoir computing to provide insight into their computation properties, the neurons in conventional cultured neuronal networks are randomly connected, generating atypical dynamics characterized by highly correlated bursting activity not observed in healthy brains. In this study, we used micropatterning technology to fabricate BNNs with modular topology, a structural feature conserved in brain networks, and to understand how the dynamics within non-random networks of neuronal cells are linked to computing. Our study demonstrated that the modular BNN reservoir is capable of classifying both image and time-series data above chance levels. The modular structure in BNN contributes to the increased reservoir computing performance, in line with previous computational models with neuromorphic networks. Combining experiments with biological neuronal network and computational modeling can advance our understanding of computing principles in multicellular neuronal networks.
Bottom-Up Investigation of Multicellular Computing Within Biological Neuronal Networks

Yamamoto Hideaki, Sumi Takuma, Sato Yuya, Sato Shigeo, Hirano-Iwata Ayumi

IEICE Proceeding Series　2023/09/21

More details Close

In this presentation, we will first introduce our studies aimed at reproducing an evolutionarily-conserved net-work structure in cultured neuronal networks on engineered glass coverslips and CMOS-based high-density microelectrode arrays. We then describe our recent attempts to couple the engineered neuronal networks with external stimulation to reveal their response to noise and spatiotemporally-patterned inputs to show that bioengineering technologies offer novel tools in investigating computational aspects of multicellular networks of biological neurons.
Time-Series Classification in Micropatterned Neuronal Network Reservoirs

Takuma Sumi, Hideaki Yamamoto, Yuichi Katori, Koki Ito, Shigeo Sato, Ayumi Hirano-Iwata

IEICE Proceeding Series　2022/12/12

More details Close

Reservoir computing provides a novel framework to understand how the dynamics within biological neuronal networks (BNNs) is linked to information processing. Here, we used micropatterned substrates to fabricate BNNs with modular topology, one of the important structural features of brain networks, and realized a reservoir system with the modular BNN. Using image and time-series classification tasks, we evaluated the reservoir computing properties of the BNN reservoirs. The results show that modularity facilitates the separation between the trajectories of the neuronal responses to different spatial patterns, pointing to the functional advantage of the animals to modular topology within the nervous systems.
Parallel recordings of hERG channel currents using a solvent-free lipid bilayer microarray

Tadaki Daisuke, Miyata Ryusuke, Yamaura Daichi, Araki Shun, Sato Madoka, Komiya Maki, Ma Teng, Yamamoto Hideaki, Niwano Michio, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2021/02/26
Reservoir computing properties of in-silico/in-vitro modular neuronal networks

Sumi Takuma, Yamamoto Hideaki, Takemuro Taiki, Moriya Satoshi, Sato Shigeo, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2021/02/26
Introduction of lateral voltage as a new input for artificial lipid bilayer systems

Watanabe Takaya, Sato Madoka, Komiya Maki, Kanomata Kensaku, Ma Teng, Tadaki Daisuke, Hirose Fumihiko, Hirano Ayumi

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2021

More details Close

Phospholipid bilayer is the basic structure of cell membranes. Artificially formed planar bilayer lipid membrane (BLM) has been widely used as a system for the functional analysis of membrane proteins. However, the measurement method has remained unchanged for several decades. Transmembrane voltage is usually used as the input, and the measured transmembrane current is used as the output of the system. In this work, we propose a method to improve the control of the BLM system by applying a voltage parallel to the BLM (lateral voltage) in addition to the traditional transmembrane voltage. The effects of the lateral voltage on the ion-channel-incorporated BLM systems were investigated.
Interfacial structure and size distribution of nanobubbles

Niwano Michio, Iwata Kazuki, Ma Teng, Tadaki Taisuke, Hirano-Iwata Ayumi

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2021

More details Close

We have investigated the particle size distribution of nanobubbles (NBs) the nanoparticle tracking analysis method and found that the particle size is discrete and increases by a factor of √2. We interpreted that this peculiar particle size distribution is caused by the fact that NBs of the same size tend to coalesce with each other, and simulated the particle size distribution incorporating this effect, and found that it can generally reproduce the experiment. The results of recent studies on the interfacial structure of NBs will also be presented.
Impact of electrical field noise on micropatterned neuronal networks

Sumi Takuma, Yamamoto Hideaki, Wakimura Kei, Sato Shigeo, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2020/02/28
Coalescence and stability of nanobubbles

庭野道夫, MA Teng, 但木大介, 平野愛弓, 平野愛弓

応用物理学会春季学術講演会講演予稿集(CD-ROM)　2020
Fabrication of pressure mapping sensors based on piezoelectric PVDF films in which micro metal wires are embedded as electrodes

松本晋太朗, 但木大介, 山宮慎, MA Teng, 今井裕司, 平野愛弓, 平野愛弓, 庭野道夫

応用物理学会春季学術講演会講演予稿集(CD-ROM)　2020
Highly sensitive hydrogen detection of a gas sensor based on TiO2 nanotube thin films

木村康男, 阿部宏之, MA Teng, 但木大介, 平野愛弓, 平野愛弓, 庭野道夫

応用物理学会春季学術講演会講演予稿集(CD-ROM)　2020
Coalescence mechanism of nanobubbles

庭野道夫, MA Teng, 但木大介, 平野愛弓, 平野愛弓

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　2020
Bio-hybrid membrane as a platform for new nanodevices

Ma Teng, Feng Xingyao, Tadaki Daisuke, Hirano-Iwata Ayumi

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2020

More details Close

In this presentation, a new platform based on bio-hybrid membranes will be proposed and discussed in detail. The bio-hybrid membrane is a 2D structure composed of lipid molecules and functional nanomaterials. It has the advantage of lipid bilayer structure, such as flowability, ultrathin thickness and ultrahigh resistance. At the same time, it possesses optical, electrical, magnetic functionality of the nanomaterials. Furthermore, due to the unique molecular packing in the structure, new properties can be discovered from the bio-hybrid membrane. Using the bio-hybrid membrane, we were able to discover unique properties and fabricate high-performance photodetectors and gas sensors. The bio-hybrid membrane introduced here is a flexible and feasible platform for novel nanodevices.
Culturing primary neurons on an ultrasoft silicone gel with biomimetic stiffness

Sumi Takuma, Yamamoto Hideaki, Hirano-Iwata Ayumi

JSAP Annual Meetings Extended Abstracts　2019/09/04
The self-assembly of nanoparticle-inserted hybrid lipid membranes at water/air interface

Xingyao Feng, Teng Ma, Takafumi Deguchi, Ayumi Hirano-Iwata

2019/04/18
金チオール修飾表面を用いたPVDF膜中の分極処理

但木大介, 山宮慎, 馬騰, 今井裕司, 平野愛弓, 庭野道夫

電子デバイス研究会　2019/04/18
In-situ observation of photocatalytic degradation of organic molecules by TiO2 nanotube arrays

Teng Ma, Yasuo Kimura, Michio Niwano, Ayumi Hirano-Iwata

2019/04/18
ナノ・マイクロ加工に基づく人工細胞膜デバイスの創成と薬物副作用センサへの応用

平野愛弓, 但木大介, 山浦大地, 加藤美生, 小宮麻希, 井上遥, 戸澤譲, 馬騰, 山本英明, 庭野道夫

電子デバイス研究会　2019/04/18
白金微粒子を坦持した酸化チタンナノチューブ薄膜を用いた高感度ガスセンサ

阿部宏之, 馬騰, 但木大介, 平野愛弓, 木村康男, 庭野道夫

平成31年電気学会全国大会　2019/03/14
完全混合する脂質二重膜中でコレステロールが誘起するマイクロドメイン形成

ゴーウェイシェンメルヴィン, 平野愛弓, 庭野道夫, 手老龍吾

第66回応用物理学会春季学術講演会　2019/03/11
Self-assembled Lipid Membranes Doped with Organic Molecules

Xingyao Feng, Teng Ma, Takafumi Deguchi, Ayumi Hirano-Iwata

2019/03/11
マイクロパターン培養細胞を用いた神経回路応答の構成論的解析

早川岳志, 山本英明, 平野愛弓

第66回応用物理学会春季学術講演会　2019/03/11
規則ナノ細孔を有する多孔質アルミナ薄膜を用いたナノバブル発生

庭野道夫, 馬騰, 但木大介, 平野愛弓

第66回応用物理学会春季学術講演会　2019/03/11
フラーレン微粒子ドープ脂質二分子膜の導電率制御

八巻友祐, 長谷山拓実, 鹿又健作, 吉田一樹, 有馬ボシールアハンマド, 平野愛弓, 廣瀬文彦

電子情報通信学会CPM研究会　2019/03/01
人工脂質二分子膜系と無細胞合成系の融合に基づくhERGチャネルに対する薬物副作用の定量

横田澪央, 加藤美生, 山浦大地, 常田悠介, 佐藤まどか, 但木大介, 小宮麻希, 山本英明, 井上遥香, 戸澤譲, 庭野道夫, 平野愛弓

電子情報通信学会CPM研究会　2019/03/01
P3HTを混合した自立型脂質二分子膜の光応答特性

平田はるか, 冨岡康貴, 高島匠吾, 守屋雅隆, 廣瀬文彦, 平野愛弓, 水柿義直

電子情報通信学会CPM研究会　2019/03/01
粒径の異なる2種類の金ナノ粒子から成るランダム配列の電気的特性

関根一真, 森林誠, 守屋雅隆, 谷貝知起, 島田宏, 平野愛弓, 廣瀬文彦, 水柿義直

電子情報通信学会CPM研究会　2019/03/01
マイクロ加工技術に基づく人工細胞膜デバイスの開発 Invited

平野愛弓

日本学術振興会産学協力研究委員会半導体界面制御技術第154委員会第111回研究会　2019/02/01
Structural evolution for highly efficient perovskite solar cells International-presentation

Teng Ma, Ayumi Hirano-Iwata

International Conference on Perovskite and Organic Photovoltaics and Optoelectronics　2019/01/28
圧力マッピングへの応用を指向した金属細線包埋型PVDF薄膜センサの作製

但木大介, 山宮慎, MA Teng, 今井裕司, 平野愛弓, 平野愛弓, 庭野道夫

応用物理学会春季学術講演会講演予稿集(CD-ROM)　2019
多孔質アルミナ薄膜を用いて発生したナノバブルの特性

庭野道夫, MA Teng, 但木大介, 平野愛弓, 平野愛弓

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　2019
白金微粒子担持した酸化チタンナノチューブ薄膜を用いた高感度ガスセンサ

阿部宏之, MA Teng, 但木大介, 平野愛弓, 平野愛弓, 木村康男, 庭野道夫

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　2019
人工細胞膜に基づいたイオンチャネルタンパク質の新規解析系の開発

小宮麻希, 横田澪央, 常田悠介, 佐藤まどか, 加藤美生, 山浦大地, 但木大介, 馬騰, 山本英明, 庭野道夫, 平野愛弓, 平野愛弓

日本分析化学会年会講演要旨集(Web)　2019
Analysis of ion channel openings using bilayer lipid membranes

Yokota Ryo, Hirano-Iwata Ayumi, Tsuneta Yusuke, Sato Madoka, Kato Miki, Yamaura Daichi, Tadaki Daisuke, Komiya Maki, Yamamoto Hideaki, Niwano Michio

Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science　2019

More details Close
人工脂質二重膜内で膜タンパク質の融合サイトとして働く微小ドメイン

ゴーウェイシェンメルヴィン, 平野愛弓, 庭野道夫, 手老龍吾

電気学会光・量子デバイス研究会「医療・バイオ応用を目指したナノ加工　2018/12/20
Advantages of interdigitated structure over traditional sandwich structure for highly efficient perovskite solar cells

Teng Ma, Ayumi Hirano-Iwata

12th Aseanian Conference on Nano-hybrid Solar Cells　2018/12/18
Stable Lipid Bilayers in Microfabricated Silicon Chips as a Platform for Ion Channel Proteins Invited

HIRANO-Iwata Ayumi

Taiwan-Japan-Korea Trilateral Conference on Nanomedicine　2018/12/13
Microfabricated drug screening platforms for ion channel proteins Invited

HIRANO-Iwata Ayumi

The 19th RIES-HOKUDAI International Symposium　2018/12/11
Lipid-assisted self-assembly of bio-hybrid membranes

Xingyao Feng, Teng Ma, Takafumi Deguchi, Ayumi Hirano-Iwata

2018/12/06
Surface micropatterning techniques for reconstituting functional neuronal networks in culture Invited

H. Yamamoto, A. Hirano-Iwata

Pacific Rim Symposium on Surfaces, Coatings & Interfaces (PacSurf 2018)　2018/12/02
Ink-jet printed 3D-microelectrode arrays for neuroelectronic interfaces and sensing applications

N. Adly, L. Grob, P. Rinklin, S. Zips, K. Terkan, L. Weiss, H. Yamamoto, A. Hirano-Iwata, B. Wolfrum

2018 Materials Research Society (MRS) Fall Meeting　2018/11/25
PVDF膜中の配向分極制御のための金表面処理

山宮慎, 但木大介, 馬騰, 今井裕司, 平野愛弓, 庭野道夫

日本表面真空学会学術講演会　2018/11/19
モジュール構造型神経回路モデルにおける興奮性－抑制性均衡とネットワークダイナミクス

守谷哲, 山本英明, 袁之雄, 井手克哉, 脇村桂, 平野愛弓, 久保田繁, 佐藤茂雄

電子情報通信学会ニューロコンピューティング(NC)研究会　2018/10/19
階層的モジュール構造を有する神経回路網モデルにおける活動パターンの機能的複雑性

袁之雄, 山本英明, 守谷哲, 井手克哉, 久保田繁, 佐藤茂雄, 平野愛弓

電子情報通信学会ニューロコンピューティング(NC)研究会　2018/10/19
シリコン微細加工に基づく薬物副作用センサの開発 Invited

平野愛弓

第9回有機分子・バイオエレクトロニクスの未来を拓く若手研究者討論会　2018/09/29
階層的モジュール構造を有する培養神経回路のin vitro再構成

井手克哉, 山本英明, 脇村桂, 守谷哲, 袁之雄, 久保田繁, 佐藤茂雄, 平野愛弓

第79回応用物理学会秋季学術講演会　2018/09/18
Auチオール修飾表面を用いたPVDF膜中の配向分極制御

山宮慎, 但木大介, 馬騰, 今井裕司, 平野愛弓, 庭野道夫

第79回応用物理学会秋季学術講演会　2018/09/18
Bottom-up engineering of neuronal nework function using microfabricated surfaces Invited

H. Yamamoto, K. Ide, K. Wakimura, A. Hirano-Iwata

European Materials Research Society (E-MRS) 2018 Fall Meeting　2018/09/17
Microfabricated Silicon Devices for Ion Channel Reconstitution Invited

HIRANO-Iwata Ayumi

2018/09/16
半導体微細加工で創る薬物副作用センサチップ Invited

平野愛弓

第３５回無機・分析化学コロキウム　2018/06/01
イオンチャネル計測に用いられる脂質二重膜内のマイクロドメインのフォスファチジルエタノールアミン濃度依存性

メルヴィンゴーウェイシェン, 平野愛弓, 庭野道夫, 手老龍吾

電子デバイス研究会　2018/04/20
金ナノ粒子ランダム入れるにおいて観測された単一電子トランジスタ的な特性

長谷山拓実, 鹿又健作, 三浦正範, 有馬ボシールアハマド, 久保田繁, 手老龍吾, 平野愛弓, 廣瀬文彦

電子デバイス研究会　2018/04/20
微細加工に基づく人工細胞膜の安定化と薬物副作用センサへの応用

平野愛弓, 但木大介, 山浦大地, 荒田航平, 大堀健, 井上遥香, 馬騰, 山本英明, 戸澤譲, 庭野道夫

電子デバイス研究会　2018/04/20
Lateral Charge transport in perovskite soalr cells

Teng Ma, Daisuke Tadaki, Michio Niwano, Ayumi Hirano-Iwata

2018/04/19
金属細線を包埋したPVDFフレキシブル圧力センサの作製

但木大介, 山宮慎, 馬騰, 今井裕司, 平野愛弓, 庭野道夫

電子デバイス研究会　2018/04/19
The full potential of integrated-back-contacted perovskite solar cells unveiled by numerical simulation technique

Teng Ma, Daisuke Tadaki, Michio Niwano, Ayumi Hirano-Iwata

Materials Research Society 2018 spring meeting　2018/04/06
Ag細線を包埋したPVDFフレキシブル圧力センサ

山宮慎, 但木大介, 馬騰, 今井裕司, 平野愛弓, 庭野道夫

第65回応用物理学会春季学術講演会　2018/03/18
PCBM包埋脂質二分子膜への光照射における電流応答

出口貴史, 馬騰, 鹿又健作, 山浦大地, 但木大介, 廣瀬文彦, 平野愛弓

第65回応用物理学会春季学術講演会　2018/03/18
Boosting the power conversion efficiency of perovskite solar cells

T. Ma, D. Tadaki, M. Niwano, A. Hirano-Iwata

2018/03/17
ITO支持型脂質二分子膜の光センサ応用

長谷山拓実, 鹿又健作, 有馬ボシールアハマド, 三浦正範, 久保田繁, 手老龍吾, 平野愛弓

電子情報通信学会電子部品材料研究会若手ミーティング　2018/03/02
生体二次元材料・脂質二分子膜に基づくバイオデバイスの創成 Invited

平野愛弓

グラフェンコンソーシアム第16回研究講演会　2018/02/26
Biomimetic culture of primary neurons using ultrasoft gels

Sumi Takuma, Yamamoto Hideaki, Hayakawa Takeshi, Ide Katsuya, Kino Hisashi, Tanaka Tetsu, Hirano Ayumi

Abstract of annual meeting of the Surface Science of Japan　2018

More details Close

Mechanical properties of scaffolds have recently been found to impose strong impact on the behavior of cultured cells. Here, we focused on the effect of scaffold’s elastic modulus on the development of synaptic connections in cultured neurons, and established a novel system for culturing rat cortical neurons on an ultrasolft gel surface with an elastic modulus resembling the brain. Impact of the soft scaffold on the amplitude of synaptic currents and spontaneous neuronal activity, analyzed via patch -clamp recording and fluorescence calcium imaging, will also be presented.
Quantification of Drug Side Effects on Cell-Free Synthesized Ion-Channels Reconstituted in Bilayer Lipid Membranes

Kato Miki, Hirano Ayumi, Inoue Haruka, Yamaura Daichi, Yokota Reo, Komiya Maki, Tadaki Daisuke, Yamamoto Hidaka, Tozawa Yuzuru, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　2018

More details Close

We aim to develop a drug screening system based on a reconstitution system in which ion channels are embedded in an artificial lipid bilayer membrane (BLM). We have been developing stable BLMs based on silicon (Si) microfabrication. We previously reported on efficient incorporation of ion channels in BLMs. Here we applied this system to a cell-free synthesized hERG channel and tried to quantify drug side effects on this channel.
Generation of nano-bubbles by a porous alumina thin film with ordered nano-holes.

Niwano Michio, Ma Teng, Tadaki Daisuke, Hirano-Iwata Ayumi

Abstract of annual meeting of the Surface Science of Japan　2018

More details Close

We have proposed a simple method of generating nano-bubbles (NBs) by a porous alumina film with ordered nano-scaled holes. We have investigated the size distribution of NBs generated by our proposed method using the nano tracking analysis (NTA). We found that the diameter of the NBs is in the range of 50-150 nm and depends on the kind of the gas in NBs.
PCBM包埋脂質二分子膜への光照射における電流応答

出口貴史, 馬騰, 鹿又健作, 山浦大地, 但木大介, 廣瀬文彦, 平野愛弓

応用物理学会東北支部第72回学術講演会　2017/11/30
金属細線を包埋したPVDF圧力センサの作製

山宮慎, 但木大介, 馬騰, 今井裕司, 平野愛弓, 庭野道夫

応用物理学会東北支部第72回学術講演会　2017/11/30
Reconstitution of Ion Channel Functions in Artificially Formed Cell Membranes International-presentation Invited

HIRANO-Iwata Ayumi

5th Ito International Research Conference, RIKEN Contennial Anniversary, ISSP International workshop & Surface and Interface Spectroscopy 2017 (IIRC5)　2017/11/23
人工細胞膜に基づく薬物副作用センサ Invited

平野愛弓

第２１回次世代医工学研究会　2017/09/14
半導体微細加工で創る薬物副作用センサ Invited

平野愛弓

REDEEMシンポジウム　2017/09/09
単分子貼り合わせ法を用いた脂質二分子膜形成時に見られる静電容量値の変化と膜寿命との相関関係

高島匠吾, 守屋雅隆, 木村康男, 平野愛弓, 水柿義直

第78回応用物理学会秋季学術講演会　2017/09/07
マルチウェル型チャンバーによる高効率薬物副作用検査系の構築

山浦大地, 宮田隆典, 荒木駿, 但木大介, 山本英明, 平野愛弓

第78回応用物理学会秋季学術講演会　2017/09/07
ITO上PCBMドープ脂質膜の可視光照射による光起電力効果

鹿又健作, 長谷山拓実, 平野愛弓, 廣瀬文彦

第78回応用物理学会秋季学術講演会　2017/09/06
生体分子パターンの形状による神経細胞回路のモジュール間相互作用の制御

井手克哉, 山本英明, 守谷哲, 脇村桂, 谷井孝至, 秋間学尚, 久保田繁, 佐藤茂雄, 庭野道夫, 平野愛弓

第78回応用物理学会秋季学術講演会　2017/09/05
マイクロコンタクトプリンティング法による生体分子パターニングと培養神経回路の構造制御

山本英明, 松村亮佑, 井手克哉, 早川岳志, 脇村桂, 庭野道夫, 平野愛弓

第78回応用物理学会秋季学術講演会　2017/09/05
可視光応答酸化チタンの光触媒作用を活用した液中表面改質と細胞パターニング

河野翔, 黒飛敦, 服部晃平, 山本英明, 平野愛弓, 谷井孝至

第37回表面科学学術講演大会　2017/08/19
ナノ・マイクロ構造制御に基づく人工細胞膜の安定化

平野愛弓, 但木大介, 大堀健, 荒田航平, 馬騰, 山本英明, 庭野道夫

第37回表面科学学術講演大会　2017/08/19
金ナノ粒子ランダム配列において室温で観測された負性微分抵抗のゲート電圧変調

守屋雅隆, Tran Thi Thu Huong, 森林誠, 松本和彦, 島田宏, 木村康男, 平野愛弓, 水柿義直

第78回応用物理学会秋季学術講演会　2017/08/08
半導体微細加工で創るイオンチャネルセンサ Invited

平野愛弓

イオンチャネル研究会　2017/08/02
半導体微細加工で創る人工細胞膜を用いた薬物副作用センサ Invited

平野愛弓

Nanion-東京女子医科大学イオンチャネルフォーラム2017　2017/07/27
神経回路の同期的活動に対するモジュール構造の影響に関する計算論的研究

守谷哲, 山本英明, 秋間学尚, 平野愛弓, 庭野道夫, 久保田繁, 佐藤茂雄

電子情報通信学会ニューロコンピューティング(NC)研究会　2017/07/06
Reconstitution and Recording Ion Channel Activities in Artificially Formed Cell Membranes International-presentation Invited

HIRANO-Iwata Ayumi

9th International Conference on Molecular Electronics and Bioelectronics　2017/06/27
3電極間に滴下法で作製した金ナノ粒子ランダム配列における単一電子帯電効果

森林誠, 松本和彦, Tran Thi Thu Huong, 守屋雅隆, 島田宏, 木村康男, 平野愛弓, 水柿義直

電子情報通信学会電子デバイス(ED）研究会　2017/04/21
Solution-processed perovskite film for photovoltaic applications

Teng Ma, Daisuke Tadaki, Michio Niwano, Ayumi Hirano-Iwata

2017/04/21
安定な人工脂質二分子膜形成のためのテーパー構造を有した微細孔をもつ半導体シリコンチップの作製

但木大介, 山浦大地, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫, 平野愛弓

2017/04/21
自己組織化単分子膜による自立型脂質二分子膜の膜特性制御

山浦大地, 但木大介, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫, 平野愛弓

電子情報通信学会電子デバイス(ED）研究会　2017/04/21
半導体微細加工に基づく薬物副作用センサの開発 Invited

平野愛弓

2017年度電子デバイス研究会（ED研）　2017/04/21
Controlled growth of perovskite crystals for photovoltaic applications

電子情報通信学会電子デバイス(ED）研究会　2017/03/21
Microfabricated silicon devices for ion channel reconstutution

平野愛弓

第64回応用物理学会春季学術講演会　2017/03/17
微細加工シリコンチップにおける脂質二分子膜中のイオンチャネル電流計測

荒田航平, 平野愛弓, 但木大介, 山浦大地, 荒木駿, 吉田美優, 大堀健, 山本英明, 庭野道夫

第64回応用物理学会春季学術講演会　2017/03/17
半導体シリコンチップ上に作製された微細孔における安定な人工脂質二分子膜形成のためのエッジ構造の最適化

但木大介, 平野愛弓, 山浦大地, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫

第64回応用物理学会春季学術講演会　2017/03/17
Fabrication of Au-nanoparticle-embedded lipid bilayer membranes supported on solid substrates

Naotoshi Sakaguchi, Ryosuke Kimura, Yasuo Kimura, Ayumi Hirano-Iwata, Toshio Ogino

2017/03/15
モジュール構造型培養神経回路の計算論的モデリング

山本英明, 守谷哲, 井手克哉, 松村亮佑, 秋間学尚, 久保田繁, 谷井孝至, 佐藤茂雄, 庭野道夫, 平野愛弓

第64回応用物理学会春季学術講演会　2017/03/14
モジュール構造型神経回路モデルにおける自発活動パターンのばらつきに関する考察

守谷哲, 山本英明, 井手克哉, 秋間学尚, 平野愛弓, 庭野道夫, 久保田繁, 佐藤茂雄

電子情報通信学会ニューロコンピューティング(NC)研究会　2017/03/13
Functional integration of human ion channels in artificially formed bilayer lipid membranes

Hirano-Iwata Ayumi, Tadaki Daisuke, Yamaura Daichi, Araki Shun, Yoshida Miyu, Arata Kohei, Ohori Takeshi, Yamamoto Hideaki, Niwano Michio

JSAP Annual Meetings Extended Abstracts　2017/03/01
微細加工シリコン基板に基づく脂質二分子膜へのヒトイオンチャネル機能の再構成

吉田美優, 平野愛弓, 山本英明, 但木大介, 庭野道夫

2016年真空・表面科学合同講演会　2016/11/29
自己組織化単分子膜修飾による自立型脂質二分子膜の安定性の制御

山浦大地, 但木大介, 荒木駿, 吉田美優, 荒田航平, 山本英明, 荻野俊郎, 庭野道夫, 平野愛弓

2016年真空・表面科学合同講演会　2016/11/29
モジュール型神経回路モデルにおける構造と同期活動の解析

守谷哲, 山本英明, 秋間学尚, 平野愛弓, 庭野道夫, 久保田繁, 佐藤茂雄

電子情報通信学会ニューロコンピューティング(NC)研究会　2016/11/19
人工細胞膜を用いたチャネルデバイスによる薬物副作用のセンシング Invited

平野愛弓

応用物理学会有機分子・バイオエレクトロニクス分科会講習会　2016/11/07
マイクロ加工表面を用いた神経信号伝達の整流性制御

松村亮佑, 山本英明, 桂林秀太郎, 平野愛弓, 庭野道夫

第77回応用物理学会秋季学術講演会　2016/09/13
Reconstitution of human ion channels in lipid bilayers formed in microfabricated apertures

A. Hirano-Iwata, M. Yoshida, S. Araki, D. Tadaki, R. Miyata, K. Ishibashi, K. Arata, T. Ohori, H. Yamamoto, M. Niwano

2016/09/13
Reconstitution of human ion channels in lipid bilayers formed in microfabricated apertures

Hirano-Iwata Ayumi, Yoshida Miyu, Araki Shun, Tadaki Daisuke, Ishibashi Kenichi, Arata Kohei, Takeshi Ohori, Yamamoto Hideaki, Michio Niwano

JSAP Annual Meetings Extended Abstracts　2016/09/01
ナノ形状設計に基づく人工細胞膜の安定化とそのセンサ応用 Invited

平野愛弓

機能物質セミナー　2016/05/19
それぞれ粒径の異なるナノ粒子を散布して作製した2種類の単一電子素子

平野愛弓

守屋雅隆, Tran Thi Thu Huong, 松本和彦, 島田宏, 木村康男, 平野愛弓, 水柿義直　2016/04/21
固体基板への固定による生体物質の評価

荻野俊郎, 伊藤和希, 横田圭司, 小川裕太, 松村幸子, 南澤宝美后, 菅加奈子, 芝清隆, 木村康男, 平野愛弓

電子情報通信学会電子デバイス(ED）研究会　2016/04/21
安定な人工脂質二分子膜形成のための微細孔を有するシリコンチップの作製

但木大介, 平野愛弓, 石橋健一, 荒木駿, 吉田美優, 荒田航平, 大堀健, 山本英明, 庭野道夫

電子情報通信学会電子デバイス(ED）研究会　2016/04/21
微細加工脂質二分子膜チップへのイオンチャネルの包埋

平野愛弓, 吉田美優, 荒木駿, 但木大介, 山本英明, 庭野道夫

電子情報通信学会電子デバイス(ED）研究会　2016/04/21
繰り返し金ナノ粒子を散布することで作製した単一電子素子

第63回応用物理学会春季学術講演会　2016/03/21
微細加工イオンチャネルチップにおけるチャネル包埋促進

第63回応用物理学会春季学術講演会　2016/03/19
細胞シートの電気抵抗を活用した神経細胞外計測の信号増強

第63回応用物理学会春季学術講演会　2016/03/19
マイクロパターン表面を用いた培養神経回路の構造・機能制御

第63回応用物理学会春季学術講演会　2016/03/19
半導体微細加工に基づくイオンチャネル再構成系の構築と薬物スクリーニング系への応用

第８９回日本薬理学会年会　2016/03/09
Extraction of morphological features of exosomes adsorbed on substrates for host cell identification

Ito Kazuki, Ogawa Yuta, Yokota Keiji, Matsumura Sachiko, Minamisawa Tamiko, Suga Kanako, Shiba Kiyotaka, Kimura Yasuo, Hirano-Iwata Ayumi, Ogino Toshio

Abstract of annual meeting of the Surface Science of Japan　2016
Observation of metal nanoparticles incorporation into lipid bilayers by membrane fusion

Sakaguchi Naotoshi, Kimura Ryosuke, Kimura Yasuo, Hirano-Iwata Ayumi, Ogino Toshio

Abstract of annual meeting of the Surface Science of Japan　2016
Identification and molecular observation of reconstituted hERG channel in support lipid bilayer membrane

Fukumoto Kohei, Yoshida Miyu, Hirano-Iwata Ayumi, Niwano Michio, Tero Ryugo

Abstract of annual meeting of the Surface Science of Japan　2016
Development of an artificial cell membrane array based on silicon microfabrication

Araki Shun, Hirano-Iwata Ayumi, Miyata Ryusuke, Tadaki Daisuke, Ishibashi Kenichi, Yamamoto Hideaki, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　2016
Manipulating neuronal cells in situ by TiO2-assisted photocatalytic lithography International-presentation Invited

H. Yamamoto, A. Hirano-Iwata, T. Tanii, M. Niwano

9th International Symposium on Nanomedicine (ISNM2015)　2015/12/10
クラスターイオンのポリペプチドとの反応の赤外吸収分光その場観察

吉田真生, 馬騰, 山本英明, 平野愛弓, 庭野道夫

2015年真空・表面科学合同講演会　2015/12/03
エクソソームのサイズ分布と吸着様体の評価

2015年真空・表面科学合同講演会　2015/12/03
表面マイクロ改質技術を活用した培養神経細胞/回路の構造制御 Invited

山本英明, 平野愛弓, 谷井孝至, 庭野道夫

第３５回表面科学学術講演会　2015/12/01
微細加工シリコン基板を用いた人工細胞膜の構築

2015年真空・表面科学合同講演会　2015/12/01
アルミナ多孔質薄膜を用いたナノバブル発生

2015年真空・表面科学合同講演会　2015/12/01
Giand Unilamellar Vesicle の作製とマイクロポアによる評価

2015年真空・表面科学合同講演会　2015/12/01
金ナノ粒子を包埋した脂質二重膜の形態観察

2015年真空・表面科学合同講演会　2015/12/01
支持脂質二重膜を用いたhERG チャネル包埋プロテオリポソームの膜融合過程の観察

2015年真空・表面科学合同講演会　2015/12/01
Reconstitution of Ion Channel Functions in Micro-fabricated Silicon Chips International-presentation Invited

Joint Symposium of Sendai Symposium on Analytical Sciences 2015 and Tohoku Univ. –IMEC Seminar 2015　2015/11/23
Adsorption of solvent molecules on TiO2/perovskite interface and its effect on planar perovskite solar cells

第76回応用物理学会秋季学術講演会　2015/09/15
液中環境下における金ナノ粒子の脂質二重膜への導入評価

第76回応用物理学会秋季学術講演会　2015/09/15
架橋構造脂質膜作製に向けたGUVの作製と評価

第76回応用物理学会秋季学術講演会　2015/09/15
An ion-channel biosensor based on microfabrication Invited

HIRANO-Iwata Ayumi

2015/09/13
微細加工シリコン基板に基づくイオンチャネル機能の発現

第76回応用物理学会秋季学術講演会　2015/09/13
ハイドロゲル膜を用いた神経細胞－グリア細胞の接触共培養系の確立

第76回応用物理学会秋季学術講演会　2015/09/13
支持脂質二重膜へのhERGチャネルの再構成と分子分布観察

第76回応用物理学会秋季学術講演会　2015/09/13
微細加工シリコン基板を用いたイオンチャネル機能の再構成 Invited

電子情報通信学会ソサイエティー大会　2015/09/10
微細加工シリコン基板に基づく脂質二分子膜イオンチャネルチップ Invited

平野愛弓

日本分析化学会第64年会　2015/09/09
半導体微細加工で創る脂質二分子膜イオンチャネルチップ Invited

物性研・短期研究会「反応と輸送」　2015/06/24
半導体微細加工に基づく脂質二分子膜イオンチャネルチップ Invited

神奈川R&D推進協議会イノベーション研究部会技術討論会　2015/06/01
The bulk and interface of organo-lead halide perovskite layer in highly efficient perovskite solar cells－An infrared study

2015年度電子デバイス研究会（ED研）　2015/04/16
生体膜の原子間力顕微鏡による評価

2015年度電子デバイス研究会（ED研）　2015/04/16
局所陽極酸化ナノファブリケーション技術

2015年度電子デバイス研究会（ED研）　2015/04/16
赤外分光法によるナノバブルの表面洗浄効果のその場観察

2015年度電子デバイス研究会（ED研）　2015/04/16
微細加工シリコン基板に基づくイオンチャネル機能の再構成

2015年度電子デバイス研究会（ED研）　2015/04/16
シリコン微細加工で創る脂質二分子膜イオンチャネルチップ Invited

第６２回応用物理学会春季学術講演会　2015/03/13
シリコン微細加工に基づく脂質二分子膜イオンチャネルチップの開発 Invited

平野愛弓

日本学術振興会「薄膜第131委員会、半導体界面制御技術第154委員会」合同研究会　2015/02/24
Fabrication of Giant Unilamellar Vesicle and evaluation by micro-pore.

Nakayama Tomoaki, Yamaura Daichi, Kimura Ryousuke, Sakaguchi Naotoshi, Kimura Yasuo, Hirano-Iwata Ayumi, Ogino Toshio

Abstract of annual meeting of the Surface Science of Japan　2015
Membrane fusion process of proteoliposome containing human ether-a-go-go-related gene channel into supported lipid bilayer

Fukumoto Kohei, Yoshida Miyu, Hirano-Iwata Ayumi, Niwano Michio, Tero Ryugo

Abstract of annual meeting of the Surface Science of Japan　2015
In-situ observation of reactions of water cluster ions with polypeptides by infrared absorption spectroscopy

Yoshida Mao, Ma Teng, Yamamoto Hideaki, Hirano Ayumi, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　2015
Microfabricated Si Chips Containing human Ether-a-go-go-Related Gene Channels as a Platform for Drug Safety Screenings International-presentation

Ayumi Hirano-Iwata, Yutaka Ishinari, Yasuo Kimura, Michio Niwano

2014 ECS and SMEQ Joint International Meeting　2014/10/05
Simultaneous Recording of Chronoamperometric L-Glutamate Current and Field Excitatory Postsynaptic Potentials in Mouse Hippocampal Slice International-presentation

R. Matsumura, A. Hirano-Iwata, M. Niwano, T. Bliss, M. Sugawara

2014 ECS and SMEQ Joint International Meeting　2014/10/05
Recording Ion-Channel Activities Based on Microfabricated Silicon Chip

Yutaka Ishinari, Ayumi Hirano-Iwata, Yasuo Kimura, Michio Niwano

第５２回日本生物物理学会年会　2014/09/25
培養神経細胞・神経回路操作のための表面マイクロ加工技術

第５２回日本生物物理学会年会　2014/09/25

More details Close

山本英明, 谷井孝至, 庭野道夫, 平野愛弓
マウス脳スライスにおけるグルタミン酸電流に及ぼす興奮性後シナプス電位の影響

平野愛弓, 松村亮佑, 菅原正雄, 庭野道夫

日本分析化学会第63年会　2014/09/17
グルタミン酸電流と興奮性シナプス後電位の同時測定

松村亮佑, 平野愛弓, 山本英明, 庭野道夫

第75回応用物理学会秋季学術講演会　2014/09/17
ナノデバイス構築のための局所陽極酸化セルフアラインメント技術

木村康男, 平野愛弓, 庭野道夫

第75回応用物理学会秋季学術講演会　2014/09/17
マイクロコンタクトプリンティング法による培養マウス海馬神経細胞の軸索誘導

高沖英里, 山本英明, 桂林秀太郎, 木村康男, 平野愛弓, 庭野道夫

第37回日本神経科学大会　2014/09/11
Bio-electroanalytical Methods Targeted for Neuronal Functions International-presentation Invited

HIRANO-Iwata Ayumi

International Workshop “Bioelectronics”　2014/09/08
微細加工で創る脂質二分子膜イオンチャネルチップ Invited

日本学術振興会「分子系の複合電子機能第181委員会」第１９回研究会　2014/06/10
マイクロコンタクトプリンティング法に基づく培養神経細胞の極性制御

第61回応用物理学会春季学術講演　2014/03/17
微細加工シリコン基板とイオンチャネルの融合

石成裕, 平野愛弓, 山本英明, 木村康男, 庭野道夫

表面科学学術講演会要旨集　2014

More details Close

膜タンパク質の一つであるイオンチャネルは高感度な分子認識機能を有し，創薬における主ターゲットになっている。我々はイオンチャネルを人工脂質二分子膜に包埋した再構成系に基づく薬物スクリーニングチップの開発を目指しており，半導体微細加工との融合による安定な脂質二分子膜の構築について報告してきた。今回は，この安定化脂質二分子膜中への幾つかのイオンチャネル包埋について検討したので，ここに報告する。
Microfabricated silicon chips for recording ion channel activities International-presentation

A. Hirano-Iwata, Y. Ishinari, Y. Kimura, Michio Niwano

2013 MRS Fall Meeting　2013/12/01
Human Ether-a-go-go-Related Gene Channels Reconstituted in Microfabricated Silicon Chips International-presentation

Y. Ishinari, A. Hirano-Iwata, Y. Kimura, M. Niwano

2013 MRS Fall Meeting　2013/12/01
An electrochemical method for monitoring L-glutamate locally released by weak electrical stimuli International-presentation

R. Matsumura, A. Hirano-Iwata, Y. Kimura, M. Niwano

2013 MRS Fall Meeting　2013/12/01
チャネル包埋脂質二分子膜チップに基づく薬物副作用の評価

第33回表面科学学術講演会・第54回真空に関する連合講演会　2013/11/26
水クラスターイオンのシリコン酸化膜表面上の吸着・脱離過程の赤外分光計測

第33回表面科学学術講演会・第54回真空に関する連合講演会　2013/11/26
人工脂質二分子膜hERGチャネルチップの開発

第74回応用物理学会学術講演会　2013/09/16
薬物副作用評価のためのhERGチャネルチップの開発

日本分析化学会第62年会　2013/09/10
A Chip-Based Stable Lipid Bilayer for Recording Activities of Biological Channels International-presentation

Seventh International Conference on Molecular Electronics and Bioelectronics (M&BE7)　2013/03/17
18. 電気刺激によって放出された神経伝達物質グルタミン酸の時間分解計測

第61回応用物理学会春季学術講演会　2013/03/17
マウス海馬スライス内CA１領野におけるL-グルタミン酸放出量の高精度解析

応用物理学会東北支部第67回学術講演会　2012/12/06
マイクロ加工に基づく脂質二分子膜イオンチャネルセンサの開発

応用物理学会東北支部第67回学術講演会　2012/12/06
マイクロ加工に基づく生体イオンチャネルセンサーの開発

第３２回表面科学学術講演会　2012/11/20
複数チャネル同時記録のための脂質二分子膜アレイの開発

第３２回表面科学学術講演会　2012/11/20
半導体微細加工に基づくイオンチャネルチップの開発 Invited

第３２回表面科学学術講演会　2012/11/20
A Chip-Based Stable Lipid Bilayer for Recording Ion-Channel Activities International-presentation Invited

Sendai Symposium on Analytical Sciences 2012　2012/11/09
半導体加工に基づく人工脂質二分子膜イオンチャネルアレイの開発

日本分析化学会第61年会　2012/09/19
半導体加工技術を利用したイオンチャネルセンサーの開発

日本分析化学会第61年会　2012/09/19
脳スライス内グルタミン酸放出の時間変化とその放出量の高精度解析

日本分析化学会第61年会　2012/09/19
海馬スライスCA1領域での長期増強現象におけるグルタミン酸の役割の検討

日本分析化学会第61年会　2012/09/19
赤外吸収分光法による水クラスターイオンの吸着脱離過程のその場観察

第73回応用物理学会学術講演会　2012/09/11
A Chip-Based Stable Lipid Bilayer for Single-Channel Recordings International-presentation

The 2012 International Conference on Flexible and Printed Electronics　2012/09/06
半導体微細加工に基づく脂質二分子膜イオンチャネルアレイの開発

日本分析化学会東北支部みちのくシンポジウム2012　2012/07/21
半導体加工技術による人工脂質二分子膜センサの開発

第59回応用物理学関係連合講演会　2012/03/15
神経可塑性における放出グルタミン酸量の脳スライス内その場計測

第59回応用物理学関係連合講演会　2012/03/15
ナノ構造設計に基づくイオンチャネルチップの開発 Invited

大阪府立大学 N2RC拠点セミナー　2012/01/27
A Biological Ion-channel Sensor Based on Silicon Microfabrication

Oshima Azusa, Hirano-Iwata Ayumi, Mozumi Hideki, Kimura Yasuo, Niwano Michio

Abstract of annual meeting of the Surface Science of Japan　2012
Long-Term Monitoring of Cell Differentiation Using Surface Infrared Spectroscopy International-presentation

The 6th International Symposium on Surface Science (ISSS-6)　2011/12/11
Planar lipid bilayers formed in Teflon-coated silicon chips for single-channel recordings

The 6th International Symposium on Surface Science (ISSS-6)　2011/12/11
Stable and Solvent-Less Lipid Bilayers Based on Nano- and Micro-Fabrication International-presentation

2011MRS Fall Meeting　2011/11/28
Solvent-less planar lipid bilayers formed in microfabricated silicon chips International-presentation

2011MRS Fall Meeting　2011/11/28
半導体微細加工に基づく安定化脂質イオンチャネルチップの開発 Invited

平成２３年度化学系学協会東北大会　2011/09/17
半導体加工に基づくイオンチャネルチップの開発

応用物理学会有機分子・バイオエレクトロニクス分科会研究会　2011/06
Improved Stability of Lipid Bilayers Based on Nano-Fabrication International-presentation

ICAS 2011　2011/05
表面赤外分光を用いた吸着水および水クラスターの脱離過程の観測

平成22年度日本表面科学会東北・北海道支部講演会　2011/03/09
半導体加工に基づく脂質二分子膜イオンチャネルセンサの開発

第58回応用物理学関係連合講演会　2011/03
ナノ構造設計に基づく安定化脂質二分子膜センサーの開発 Invited

真空・表面科学合同講演会第３０回表面科学学術講演会第５１回真空に関する連合講演会　2010/11/04
In situ real-time monitoring of cell responses by using surface infrared spectroscopy International-presentation Invited

Ayumi Hirano-Iwata, Ryo-taro Yamaguchi, Yuki Aonuma, Yasuo Kimura, Michio Niwano

The 23rdAnnual and International Meeting of the Japanese Association for Animal Cell Technology (JAACT2010)　2010/09/04
Free-Standing Lipid Bilayers Based on Nanoporous Alumina Film International-presentation

SSDM 2010　2010/09
平面脂質二分子膜中のメソポーラスシリカへのレセプター修飾法

日本分析化学会第５９年会　2010/09
急性海馬スライスを電気刺激した際に放出されるグルタミン酸のリアルタイム計測

日本分析化学会第５９年会　2010/09
ナノ加工技術に基づく人工脂質二分子膜形成の安定化とセンサ－の応用

日本分析化学会第５９年会　2010/09
半導体加工に基づく安定化脂質二分子膜センサーの開発

平成22年度日本分析化学会東北支部若手交流会　2010/07/02
表面赤外分光を用いた細胞分化過程の長期計測

平成22年度日本分析化学会東北支部若手交流会　2010/07/02
平面脂質二分子膜中のMCM-41チャネルへのレセプターその場修飾法の検討

日本化学会第90春季年会　2010/03/26
人工脂質二分子膜に基づく分子センシング Invited

平野愛弓

平成21年度奈良先端科学技術大学院大学物質創成科学特別講演　2010/01/29
赤外吸収分光法を用いた細胞分化過程の長期観測

近藤康彦, 平野愛弓, 木村康男, 篠原康雄, 庭野道夫

応用物理学会東北支部第64回学術講演会　2009/12
ナノ構造を用いた自立型脂質二分子膜 Invited

平野愛弓, 大嶋梓, 青戸孝至, 平良祐, 木村康男, 庭野道夫

第31回日本バイオマテリアル学会大会　2009/11/16
ナノ構造設計を用いた脂質二分子膜の安定化とそのセンサー応用 Invited

平成21年度化学系学協会東北大会　2009/09/19
Planar Lipid Bilayers for L-Glutamate Sensing International-presentation Invited

A. Hirano-Iwata, A. Oshima, T. Taira, K. Aoto, Y. Kimura, M. Niwano

International Symposium innovative Nanoscience of Supermolecular Motor Proteins Working in Biomembranes　2009/09/10
NMDA刺激によるマウス脳海馬のカルシウム信号の成分とそれに対するコルチコステロンの球背う作用

小山内裕美, 鈴木章義, 小松崎良将, 平野愛弓, 川戸佳, 斎藤稔

第18回日本バイオイメージング学会学術集会　2009/09
赤外吸収分光法に基づく細胞動態の長期間観測装置の開発

第70回応用物理学会学術講演会　2009/09

More details Close

近藤康彦，平野愛弓，木村康男，篠原康雄，庭野道夫
ナノポーラス構造を用いた人工脂質二分子膜センサの開発

日本分析化学会第58年会　2009/09

More details Close

平良祐，大嶋梓，平野愛弓，木村康男，庭野道夫
半導体微細加工技術を利用した人工脂質二分子膜センサーの開発

大嶋梓, 平野愛弓, 青戸孝至, 平良祐, 木村康男, 庭野道夫

日本分析化学会第58年会　2009/09
表面赤外分光法を用いた細胞応答のリアルタイム計測 Invited

平野愛弓, 山口僚太郎, 宮本浩一郎, 木村康男, 庭野道夫

日本動物細胞工学会2009年度大会　2009/07/24
赤外吸収分光法を用いた脂質二分子膜形成過程のin situ計測

大嶋梓, 平野愛弓, 小野寺恒太, 平良祐, 木村康男, 庭野道夫

平成21年東日本分析若手交流会　2009/07
ポーラスアルミナを用いた人工脂質二分子膜形成とセンサ－への応用

平良祐, 大嶋梓, 平野愛弓, 木村康男, 庭野道夫

平成21年東日本分析若手交流会　2009/07
表面赤外分光法を用いたミトコンドリアによる酸化的リン酸化のリアルタイム計測

山口僚太郎, 平野愛弓, 木村康男, 篠原康雄, 庭野道夫

第56回応用物理学関係連合講演会　2009/04
半導体微細加工を利用した脂質二分子膜センサーの安定化

平野愛弓, 青戸孝至, 平良祐, 山口僚太郎, 木村康男, 庭野道夫

日本化学会第89春季年会　2009/03
ポーラスアルミナフィルムを用いた人工脂質二分子膜イオンチャネルセンサの開発

平良祐, 青戸孝至, 大嶋梓, 平野愛弓, 木村康男, 庭野道夫

第56回応用物理学関係連合講演会　2009/03
Ion Channel Sensors Based on Artificial Bilayer Lipid Membranes International-presentation Invited

Ayumi Hirano-Iwata, Kouji Aoto, Tasuku Taira, Yasuo Kimura, Masao Sugawara, Michio Niwano

2nd International Symposium on Nanomedicine (ISNM2009) and Asian Core Symposium –Nano and Biomedical Molecular Science–　2009/02/07
半導体微細加工による安定化脂質二分子膜の開発

青戸孝至, 平良祐, 山口僚太郎, 平野愛弓, 木村康男, 庭野道夫

応用物理学会東北支部第63回学術講演会　2008/12
陽極酸化ポーラスアルミナフィルムを用いた人工脂質二分子膜センサの開発

平良祐, 青戸孝至, 平野愛弓, 木村康男, 庭野道夫

応用物理学会東北支部第63回学術講演会　2008/12
表面赤外吸収分光法を用いた薬剤投与に対する細胞応答の非標識検出

近藤康彦, 山口僚太郎, 平野愛弓, 木村康男, 庭野道夫

応用物理学会東北支部第63回学術講演会　2008/12
表面赤外分光法を用いた細胞死のリアルタイムモニタリング

平野愛弓, 山口僚太郎, 宮本浩一郎, 礒田博子, 宮崎均, 木村康男, 庭野道夫

第２８回表面科学講演大会　2008/11
表面赤外分光法を用いた脂質二分子膜形成過程のその場観察

平野愛弓, 小野寺恒太, 大嶋梓, 山口僚太郎, 木村康男, 庭野道夫

第69回応用物理学関係学術講演会　2008/09
半導体微細加工を利用したイオンチャネルセンサーの開発

青戸孝至, 平良祐, 山口僚太郎, 平野愛弓, 木村康男, 庭野道夫

第69回応用物理学関係学術講演会　2008/09
In-Situ Surface Infrared Study of DNA Hybridization on Au Island Films Deposited on Si Surfaces International-presentation

A. Hirano-Iwata, K. Tanaka, Y. Kimura, M. Niwano

SSDM2008　2008/09
In-situ Monitoring of Leukemia Cell Death by Infrared Spectroscopy International-presentation

R. Yamaguchi, A. Hirano-Iwata, Y. Kimura, K. Miyamoto, H. Miyazaki, H. Isoda, M. Niwano

SSDM2008　2008/09
グルタミン酸脳内測定法の開発と神経可塑性現象への応用 Invited

平成20年度東北支部分析化学若手交流会　2008/07/18
赤外分光法を用いた細胞活動の計測

山口僚太郎, 平野愛弓, 宮本浩一郎, 礒田博子, 宮崎均, 木村康男, 庭野道夫

みちのく分析科学シンポジウム2008　2008/07
Island状金薄膜へのDNA固定化とハイブリダイゼーションの表面赤外分光法による検出

平野愛弓, 田中公貴, 木村康男, 庭野道夫

第55回応用物理学関係連合講演会　2008/03
表面赤外分光法を用いた細胞死の定量的・定性的評価

山口僚太郎, 平野愛弓, 宮本浩一郎, 礒田博子, 宮崎均, 木村康男, 庭野道夫

第55回応用物理学関係連合講演会　2008/03
Label-Free Detection of Antigen-Antibody Interactions at the GaAs/Water Interface through Surface Infrared Spectroscopy: Discrimination between Specific and Non-specific Interactions by Using Secondary Structure Analysis International-presentation Invited

Ayumi Hirano-Iwata, Kota Onodera, Ko-ichiro Miyamoto, Yasuo Kimura, Masatoshi Kataoka, Yasuo Shinohara, Michio Niwano

China-Japan Symposium of Nano-Chemical Biology　2007/11/09
表面赤外分光法を用いる抗原抗体反応の非標識検出：２次構造解析による特異・非特異信号の識別

平野愛弓, 小野寺恒太, 宮本浩一郎, 片岡正俊, 篠原康雄, 木村康男, 庭野道夫

第２７回表面科学講演大会　2007/11
多重内部反射型赤外吸収分光による金薄膜上のDNA固定化とハイブリダイゼーションの検出

田中公貴, 平野愛弓, 木村康男, 庭野道夫

第２７回表面科学講演大会　2007/11
赤外分光による細胞活動のその場観察のための装置内培養環境の構築

山口僚太郎, 宮本浩一郎, 礒田博子, 宮崎均, 木村康男, 平野愛弓, 庭野道夫

第６８回応用物理学会学術講演会　2007/09
表面赤外分光法を用いたポーラスアルミナ細孔中でのDNA分子の挙動解析

平野愛弓, 山口僚太郎, 石橋健一, 宮本浩一郎, 木村康男, 庭野道夫

第６８回応用物理学会学術講演会　2007/09
In-Situ Surface Infrared Study of DNA Attachment and Hybridization at Si Surfaces International-presentation

A. Hirano, K. Tanaka, K. Ishibashi, K. Miyamoto, Y. Kimura, M. Niwano

SSDM2007　2007/09
In-Situ Detection and Classification of DNA by Porous Alumina Filter in Conjugation with Infrared Absorption Spectroscopy International-presentation

R. Yamaguchi, A. Hirano, K. Ishibashi, K. Miyamoto, Y. Kimura, M. Niwano

SSDM2007　2007/09
表面赤外分光を用いた抗原抗体反応の非標識検出

平野愛弓, 小野寺恒太, 宮本浩一郎, 木村康男, 片岡正俊, 篠原康雄, 庭野道夫

第６８回分析化学討論会　2007/05
Label-free Detection and characterization of an antigen-antibody interaction by infrared absorption spectroscopy International-presentation

K. Onodera, A. Hirano, K. Miyamoto, Y. Kimura, M. Kataoka, Y. Shinohara, M. Niwano

EMRS 2007 Spring Meeting　2007/05
Label-Free Detection and Conformational Analysis of Antigen-Antibody Interactions at GaAs Surfaces by surface Infrared Spectroscopy. International-presentation Invited

A. Hirano, K. Onodera, K. Miyamoto, Y. Kimura, M. Kataoka, Y. Shinohara, M. Niwano

1st International Symposium on Nanomedicine-from Basic to Applications-(ISNM2007) and 2nd Molecule-Based Information Transmission and Reception (MB-ITR2007)　2007/04/21
Electroosmotic Flow and Electromigration of DNA Molecules in a Microfluidic Device Investigated by Surface Vibration Spectroscopy. International-presentation

T. Miyoshi, A. Hirano, R. Yamaguchi, K. Miyamoto, Y. Kimura, M. Niwano

2007 MRS Spring Meeting　2007/04
表面赤外分光法を用いた抗原抗体反応の非標識検出

平野愛弓, 小野寺恒太, 宮本浩一郎, 片岡正俊, 篠原康雄, 木村康男, 庭野道夫

表面科学会ソフトナノテクノロジー研究部会3月ワークショップ　2007/03
表面赤外分光法を利用したマイクロ流路中のDNAの泳動挙動解析

平野愛弓, 三好智之, 山口僚太郎, 木村康男, 庭野道夫

第54回応用物理学関係連合講演会　2007/03
赤外吸収分光法を用いたDNA固定化Si表面におけるハイブリダイゼーション反応の検出III

田中公貴, 石橋健一, 平野愛弓, 宮本浩一郎, 山口僚太郎, 平野愛弓, 木村康男, 庭野道夫

第54回応用物理学関係連合講演会　2007/03
表面赤外分光法を用いた抗原抗体反応の溶液中その場観察

小野寺恒太, 宮本浩一郎, 片岡正俊, 篠原康雄, 平野愛弓, 木村康男, 庭野道夫

第54回応用物理学関係連合講演会　2007/03
Surface infrared spectroscopic study for immobilization of a peptide antigen on GaAs surfaces International-presentation

K.Onodera, K. Miyamoto, A. Hirano, Y. Kimura, M. Kataoka, Y. Shinohara, M. Niwano

Fourth International Conference on Molecular Electronics and Bioelectronics　2007/03
LTP/LTD in area CA1 in vitro is associated with a persistent increase/decrease in activity-dependent efflux of extracellular glutamate: real-time measurements using a novel glutamate-sensitive microelectrode. International-presentation

A. Hirano, M. L. Errington, M. Sugawara, T. V, P. Bliss

FENS 2006, 5th Forum of European Neuroscience　2006/07
大脳中の情報伝達物質を対象とする分子センシング法の開発 Invited

日本分析化学会第５４年会　2005/09/15
コルチコステロンがマウス脳海馬におけるカルシウム信号に与える影響

小山内裕美, 佐藤了, 門間俊博, 平野愛弓, 斎藤稔, 川戸佳

日本生物物理学会第４１回年会　2003/09
グラミシジンシングルチャンネルセンサーの応答機序の検討

松野友香, 小曽野千恵, 平野愛弓, 菅原正雄

日本分析化学会第５２年会　2003/09
マウス脳スライス内アラキドン酸放出の領野間分布のその場測定

斉藤博人, 平野愛弓, 菅原正雄

日本分析化学会第５２年会　2003/09
アビジン修飾基板に固定化したDNA中の脱塩基部位の蛍光検出

柳澤博幸, 平野愛弓, 清澤裕子, 菅原正雄

日本分析化学会第５２年会　2003/09
A Glass Capillary Microsensor for the Detection of L-Glutamate Release from Mouse Brain Slices. International-presentation

A. Hirano, M. Sugawara

Second International Conference on New Biomedical Materials Basic and Applied Sciences　2003/04
レセプター包埋脂質二分子膜及び酵素膜を用いるL-グルタミン酸センシング法の開発 Invited

第8回ナノ反応場とバイオエレクトロニクスインターフェイス制御研究会　2003/03/11
スロープ解析法による脳スライス内L-グルタミン酸の可視化

平野愛弓, 森寺信勝, 明石麻衣, 斎藤稔, 菅原正雄

日本化学会第８３春季年会　2003/03
神経伝達物質の脳内分布を可視化するための酵素膜イメージング法 Invited

第6回機能構造と分析化学シンポジウム　2002/11/28
脳スライスから放出されるL-グルタミン酸の酵素膜イメージング：差分解析によるリアルタイムイメージング法への展開

平野愛弓, 森寺信勝, 斎藤稔, 菅原正雄

日本分析化学会第５１年会　2002/09
新しい作動原理のイオンチャンネルセンサーの開発

松野友香, 平野愛弓, 菅原正雄

日本分析化学会第５１年会　2002/09
グラミシジンを情報変換素子に用いる新しいイオンチャンネルセンサーの開発

平野愛弓, 若林正樹, 松野友香, 菅原正雄

日本化学会第８１春季年会　2002/03
パッチクランプ法を用いるマウス脳スライス内NMDAレセプター分子種の同定法

平野愛弓, 清野真生, 菅原正雄

日本化学会第８１春季年会　2002/03
マウス脳スライス中のアラキドン酸放出の検出

生田目裕子, 平野愛弓, 菅原正雄

日本化学会第８１春季年会　2002/03
マウス脳スライス内NMDAレセプター分子種の電気化学的識別

平野愛弓, 清野真生, 菅原正雄

日本分析化学会第５０年会　2001/11
20.In situ生体膜センサーを用いるマウス脳スライス中のアラキドン酸放出の検出

生田目裕子, 平野愛弓, 菅原正雄

日本分析化学会第５０年会　2001/11
蛍光色素含有を用いた損傷DNAの高感度検出

酒井佳穂里, 平野愛弓, 菅原正雄

日本分析化学会第５０年会　2001/11
Voltammetric Detection of Abasic Sites in DNA with an Aldehyde Reactive Probe (ARP)-Modified Gold Electrode. International-presentation

A. Hirano, N. Simokawa, K. Osaki, M. Sugawara

IUPAC International Congress on Analytical Sciences 2001 (IUPAC ICAS 2001)　2001/08
イオンサンプリング能をもつ超微小ガラスキャピラリー電極の開発

中島久美子, 金井美季, 平野愛弓, 菅原正雄

日本化学会第７９春季年会　2001/03
スルホローダミンB含有リポソームを用いる損傷DNAの可視化検出

酒井佳穂里, 作道光晴, 平野愛弓, 菅原正雄

日本化学会第７９春季年会　2001/03
Evaluation and Comparison of Ion Permeation and Agonist Selectivities for the NMDA Receptors with Different Subunit Compositions in Bilayer Lipid Membranes Based on Integrated Single-Channel Currents. International-presentation

A. Hirano, M. Sugawara, S. Uchino

The 2000 International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2000)　2000/12
15.グルタミン酸レセプター分子種のアゴニスト選択性の電気化学的評価：情報変換能は結合能とパラレルか？

平野愛弓, 菅原正雄

日本分析化学会第４９年会　2000/09
16.逆行性神経伝達物質アラキドン酸と平面脂質二分子膜との相互作用の電気化学的評価：キャリア機構及びチャンネル機構の存在

日本分析化学会第４９年会　2000/09

More details Close

生田目裕子，平野愛弓，菅原正雄
微小脂質二分子膜シングルチャンネルセンサー：NMDAレセプター分子種を透過するCa2+イオン量の電気化学的評価

若林正樹, 平野愛弓, 内野茂夫, 飯島貞代, 菅原正雄

日本化学会第78春季年会　2000/03
NMDA受容体発現株を用いた薬理学的多様性の解析および医薬評価系の応用利用

薬理学会関東部会　1999/10

More details Close

内野茂夫，渡辺和加子，平野愛弓，菅原正雄，中村健，工藤佳久，飯島定代，三品昌美
神経伝達物質Ｌ－グルタミン酸のセンシングプレートの開発

木戸直子, 浅川美奈子, 平野愛弓, 菅原正雄

日本分析化学会第４８年会　1999/09
Ca2+存在下におけるNMDAレセプター分子種のアゴニスト選択性の電気化学的評価

平野愛弓, 若林正樹, 内野茂夫, 飯島貞代, 菅原正雄

日本分析化学会第４８年会　1999/09
グルタミン酸レセプター分子種の総イオン透過量の電気化学的評価：異なるサブユニット間での比較

平野愛弓, 若林正樹, 神田博史, 酢谷真木子, 中原健一郎, 内野茂夫, 飯島貞代, 菅原正雄

第６０回分析化学討論会　1999/05
サブスタンスPセンサーの開発

平野愛弓, 佐藤邦彦, 比田直輝, 菅原正雄

第６０回分析化学討論会　1999/05
異なるサブユニット組成をもつグルタミン酸レセプター分子種の総イオン透過量の電気化学的評価

平野愛弓, 若林正樹, 神田博史, 酢谷真木子, 中原健一郎, 内野茂夫, 飯島貞代, 菅原正雄

日本化学会第７６春季年会　1999/03
サブスタンスＰに応答する電気化学センサーの開発

平野愛弓, 佐藤邦彦, 比田直輝, 菅原正雄

日本化学会第７６春季年会　1999/03
Comparison of Total Ion Fluxes through a Single Recombinant epsilon1/zeta1 NMDA Receptor among Different Subunit Compositions. International-presentation

A. Hirano, M. Sugawara, S. Uchino, S. Nakajima-Iijima

43RD Annual Meeting (Biophysical Society)　1999/02
平面脂質二分子膜グルタミン酸イオンチャンネルセンサー：分子種に基づくアゴニスト選択性の評価

平野愛弓, 菅原正雄, 梅澤喜夫, 内野茂夫, 飯島貞代

第５９回分析化学討論会　1998/05
グルタミン酸レセプターイオンチャンネルの分子種に基づくアゴニスト選択性の評価

平野愛弓, 菅原正雄, 梅澤喜夫, 内野茂夫, 飯島貞代

電気化学会第６５回大会　1998/04
イオン選択性電極を用いたグルタミン酸受容体包埋リポソームからのCa2+イオン放出量に基づくアゴニスト選択性の評価法

中西淳, Hanna Radecka, 平野愛弓, 菅原正雄, 梅澤喜夫

日本化学会第７４春季年会　1998/03
平面脂質二分子膜グルタミン酸イオンチャンネルセンサー：アゴニスト化学選択性の新しい評価法

平野愛弓, Marián Rehák, 中西淳, 河合勲二, 佐藤準, 菅原正雄, 梅澤喜夫

日本分析化学会第４６年会　1997/10
グルタミン酸レセプター包埋リポソームから放出されるCa2+イオンのCa2+イオン選択性電極測定に基づくアゴニスト化学選択性の評価法

中西淳, Hanna Radecka, 平野愛弓, 菅原正雄, 梅澤喜夫

日本分析化学会第４６年会　1997/10
グルタミン酸イオンチャンネルセンサー：アゴニスト化学選択性の評価法

平野愛弓, Marián Rehák, 中西淳, 河合勲二, 佐藤準, 菅原正雄, 梅澤喜夫

電気化学会第６４回大会　1997/03

Show all Show first 5

Research Projects 21

Modeling neurodegenerative diseases in artificial neuronal networks

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

Institution: Tohoku University

2022/10/07 - 2026/03/31
In Vitro Reconstitution of Multicellular Computing Systems

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Transformative Research Areas (B)

Institution: Tohoku University

2021/08/23 - 2024/03/31
Lateral biasに基づく革新的膜タンパク質機能解析場の構築

平野愛弓, 但木大介, 馬騰, 山本英明, 小宮麻希, 火原彰秀

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 挑戦的研究(開拓)

Institution: 東北大学

2020/07/30 - 2024/03/31

More details Close

Lateral bias印加のための電極内蔵型支持体を作製し，この支持体中での膜形成について検討した．ベース素材としてはシリコン（Si）チップとテフロンフィルムの2種を比較した．その結果，いずれの素材においても脂質二分子膜の形成が可能であったが，Siチップでは脂質分子のみで膜形成が可能であるのに対し，テフロンフィルムでは孔周辺にヘキサデカンの塗布が必要であった．次に，これらの膜系にLateral biasを印加したところ，Siチップ系では交流電圧が，テフロンフィルム系では直流電圧が低ノイズ計測に適していることが分かった．さらに，形成した脂質二分子膜中にフラーレン誘導体（PCBM）や生体イオンチャネルを包埋し，Lateral biasの効果について検討した結果，PCBMドープ膜が示す膜貫通方向の光誘起電流や，電位依存性Naチャネルが示す膜貫通電流が，ともにLateral biasによって増大する現象を見出した（Faraday Discussion, in press, 2022）．しかし，その作用メカニズムは不明であったため，平面脂質二分子膜に対する蛍光観測系を立ち上げ，Lateral biasの作用メカニズムについて蛍光プローブを用いた検討を進めた．また，上述の電極内蔵型支持体では，Lateral biasの印加に伴って電極材料のチタン（Ti）が酸化チタン（TiO2）へと変化するという課題も判明したが，Ti電極を白金（Pt）で被覆することによって酸化を防止できることも分かった．来年度は，電極内蔵型支持体の量産化も進め，メカニズムの検討および応用探索を加速化していく予定である．
Research and Development of Computational Storage Technology to Realize Large Scale Neuron Structure Visualization

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2020/04/01 - 2024/03/31
単一イオンチャネル分子／バイオ二次元物質ハイブリッド膜の機能解析と応用

平野愛弓, 但木大介, 馬騰, 山本英明, 小宮麻希, 戸澤譲

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2019/04/01 - 2023/03/31

More details Close

脂質二分子膜の膜内に，膜に平行な方向に電圧を印加するための電極内蔵型膜支持体を，シリコン（Si）チップおよびテフロンフィルムの2種類の素材をベース材料として作製した．これらの支持体中での脂質二分子膜形成が，電極の存在によって影響を受けないことを確認した後，膜平行電圧印加に伴う膜電気特性の変化について，ノイズ電流レベル，膜抵抗，電気容量の観点から評価した．さらに，形成した脂質二分子膜中にナノ材料や生体イオンチャネルを包埋し，これらのハイブリッド膜に対する膜平行電圧の効果について検討した．その結果，フラーレン誘導体のPCBMドープ膜が示す膜貫通方向の光応答電流や，電位依存性Naチャネルが示す膜貫通電流が，ともに膜平行電圧の印加によって変調・増強されることを見出した（Faraday Discussion, in press,2022）．この膜平行電圧による膜貫通電流の増強作用や，PCBMドープ膜の光応答電流については，どちらも興味深い現象ではあるが発生メカニズムが不明であったため，2021年度は，脂質二分子膜系に対する蛍光測定系を立ち上げ，これらの現象の作用メカニズムについて蛍光プローブを用いて検討した．また，上述の膜支持体では，チタン（Ti）を電極材料として用いていたが，膜平行電圧の印加に伴って，コンタクト部位が酸化チタン（TiO2）へと変化しやすいことも分かってきた．そこで，Ti電極上への白金（Pt）コーティングを検討した結果，電極の酸化防止に効果的であった．一方，TiO2はそれ自体が魅力的なチューブ状ナノ構造体であり，このナノチューブを利用したガスセンサーの構築（Langmuir, 2021）やナノバブル生成への応用についても検討した（Sensors and Actuators: B, Chemical, in press）．
Development of microwire-embedded wearable pressure sensor

Imai Yuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

Institution: Sendai National College of Technology

2017/04/01 - 2020/03/31

More details Close

We have proposed a novel flexible sensor in which microwire-embedded β-phase poly(vinylidene fluoride) (PVDF) films are utilized. The polarization of PVDF was controlled by using thiol-modified gold surfaces that we developed in this study. We succeeded in detecting the pressure changes of the sensor in one-dimensional direction or two-dimensional plane, in accordance with a spatial resolution of 200 micrometers. Our proposed sensors would be very useful for practical realization of various wearable devices such as tactile sensors and sphygmometers.
Expression of an artificial action potential and its application to screening devices for drug side effects

Hirano-Iwata Ayumi, NIWANO MICHIO

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2015/04/01 - 2018/03/31

More details Close

In recent years, the risk evaluation of potential drug side effects to the heart is indispensable in drug discovery, and it is highly desirable to construct an artificial system for this evaluation. In this study, we tried to develop a screening platform for potential drug side effects based on artificially formed bilayer lipid membranes (BLMs) that can express action potentials. However, we faced an issue of a low efficiency in incorporation of ion-channels that are necessary for generation of action potentials. To address this issue, we investigated the process of ion channel incorporation and found that application of appropriate centrifugal forces during the incorporation process lead to a dramatic enhancement of the incorporation probability from ca. 6% to ca. 70%. We also investigated development of high-throughput assay systems for the ion channels and succeeded in simultaneous recordings of hERG channel activities in BLM systems.
Cooperative effects of natural-derived lipids and membrane proteins in lipid bilayer membranes

Tero Ryugo, FUKUMOTO Kohei, SUZUKI Yuya, NIIYAMA Yuya, OKAMOTO Yoshiaki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Toyohashi University of Technology

2015/04/01 - 2018/03/31

More details Close

This project aimed to elucidate the active state created by a plurality of membrane proteins and surrounding lipid molecules, and relating phenomena using a cell membrane model system. We reconstructed ion channel proteins that were obtained from cultured cells and cell-free protein synthesis system, in supported lipid bilayers (SLBs). Distribution and molecular structures of lipids and membrane proteins were observed by fluorescence microscopy and atomic force microscopy. We propose a model to explain the mechanism of reconstitution by clarifying the role of cell membrane derived components in SLB. We revealed that the role of intra-membrane microdomains in the reconstitution process. It is revealed that the molecular orientation of the channel protein expressed by cell-free synthesis varies depending on the reconstitution process.
Structure and function of nano-bubbles formed by a thinfilm with nano-scaled through holes

Niwano Michio

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2015/04/01 - 2017/03/31

More details Close

We have proposed a simple method of generating nano-bubbles (NBs) by a porous alumina film with ordered nano-scaled holes. We have investigated the size distribution of NBs generated by our proposed method using the nano tracking analysis (NTA) and the semiconductor surface cleaning effect of NBs using infrared absorption spectroscopy in the multiple internal reflection geometry (MIR-IRAS) and a scanning electron microscope (SEM). We found that the diameter of the NBs is in the range of 50-150 nm and depends on the kind of the gas in NBs. When a Si surface covered with an organic film was exposed to NBs in water, absorption bands originated from the film significantly decreased their absorption intensities. In addition, SEM images showed that after exposure to NBs, there appeared a number of circular traces where no carbon contaminations were observed. These observation clearly indicate the surface cleaning effect of NBs.
Single electron tunneling in lipid bilayers as a novel sensing principle

Hirano-Iwata Ayumi, NIWANO MICHIO, KIMURA YASUO, YAMAMOTO HIDEAKI

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2014/04/01 - 2016/03/31

More details Close

This study aims at realization of single-electron tunneling in lipid bilayers as a new sensing principle. We first examined incorporation of nanoparticles into lipid bilayers and found that only very small nanoparticles could be incorporated into self-standing bilayer lipid membranes. We next examined simulation on single-electron effects of aligned nanoparticles and revealed that observable single-electron effects would be possible even at room temperature. In addition, we have established fabrication procedures for silicon chips with wired metal electrodes. We would like to combine these techniques to realize single-electron tunneling in lipid bilayers and apply to highly sensitive biosensors to demonstrate a novel sensing principle.
Selfalignment local anodization technique for fabrication of simultaneous multicomponent measurement one-chip gas sensors

KIMURA Yasuo, Ma Tang, NIWANO Michio, HIRANO Ayumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

2013/04/01 - 2016/03/31

More details Close

TiO2 nanotube micro gas sensors were fabricated using the local anodization technique that is a hybrid process between photolithography and anodization technique. Catalytic metal nanoparticles such as Pt and Pd were electrochemically deposited on TiO2 nanotube surface homogeneously. Pt nanoparticles improved the sensitivity about 300 times. On the other hand, the response characteristics to hydrogen and carbon monoxide strongly depended on deposited catalytic metal nanoparticles. This result indicates that micro gas sensors with different response characteristics can be integrated on a chip and multicomponent gases can be simultaneously monitored by analyzing response characteristics.
Fabrication and evaluation of artificial neuronal networks on semiconductor surfaces

NIWANO Michio, HIRANO Ayumi, KIMURA Yasuo, YAMAMOTO Hideaki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2013/04/01 - 2015/03/31

More details Close

Human brain is a complex, hierarchical system comprised of 10 billion neurons. By engineering a simple neuronal network in vitro that mimics the in vivo architecture and functions, a novel system for studying of the dynamical properties of the neuronal networks in the brain will become available. In the current project, we developed a series of surface micromodification techniques for fabricating "template" surfaces for neuronal cell patterning. We then evaluated the spontaneous activity of the micropatterned neuronal networks via fluorescent calcium imaging. A simulation model of neuronal networks based on a biophysical model was also developed to theoretically investigate activity modulation in micropatterned networks.
Biosensing for nanospace synapses and its application to measurements of brain functions

HIRANO-IWATA Ayumi, NIWANO Michio, KIMURA Yasuo, AONUMA Yuki, YAMAMOTO Hideaki, SUGAWARA Masao

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2012/04/01 - 2015/03/31

More details Close

We have developed biosensors for bio-nanospace “synapses” and investigated their application to measurements in brain. We combined amperometric glutamate microsensor and recording of field excitatory postsynaptic potentials (fEPSPs) as a new method for analyzing relation between presynaptic and postsynaptic activities. Although it was found that electric stimuli and evoked fEPSPs induced a capacitive transient current at the microsensor, we proposed a method to extract a faradaic signal from the observed currents. Then we applied this method to long-term potentiation (LTP) in the hippocampus. It was found that the level of the extracellular L-glutamate during tetanus stimulation was significantly related to LTP induction. Thus, our simultaneous recording method for pre- and post-synaptic activities can be a useful tool for neurosciences. We also investigated efficient construction of lipid bilayer-based sensor utilizing ion channel as a sensory element for neurotransmitters.
Single-channel manipulation based on free-standing lipid bilayers

NIWANO Michio, HIRANO Ayumi, KIMURA Yasuo, AONUMA Yuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2010 - 2011

More details Close

The purpose of this study is development of an atomic force microscopy (AFM)-based method for manipulating single ion-channels through the combination of AFM and recently reported stable bilayer lipid membranes (BLMs). The final goal is that isolation of ion channels from cell membranes and subsequent incorporation of the channel into free-standing bilayer lipid membranes is made by AFM. We started with design of a solution cell and construction of cell lines expressing ion channel proteins. In addition, further improvement of stable BLMs was also achieved by coating the microfabricated silicon chips with insulator layers. We succeeded in formation of stable BLMs with electrical properties suitable for recording single-channel activities of biological ion channels
Ion channel chips based on nano-scale design

HIRANO Ayumi, NIWANO Michio, KIMURA Yasuo, AONUMA Yuki, SUGAWARA Masao

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2009 - 2011

More details Close

Artificial bilayer lipid membranes (BLMs)have attracted attention as a platform for highly sensitive biosensor and drug screening systems. However, the instability of BLMs hinders their wide range of applications. In the present study, we have succeeded in preparation of stable free-standing BLMs through the combination of silicon microfabrication and BLM formation. The BLMs were not broken by applying a constant voltage of ±1 V. The membrane lifetime was 15-45 h with and without incorporated gramicidin channel. The BLMs with incorporated channel showed tolerance to repetitive solution exchanges. Such stable membranes enable analysis of channel functions under various solution conditions from the same BLM, which will open up variety of applications including a high throughput drug screening for ion channels.
Fabrication of self-aligned room-temperature operating single electron transistor by anodization

KIMURA Yasuo, HIRANO Ayumi, NIWANO Michio, AONUMA Yuki, RAHMAN Mohammad

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2009 - 2011

More details Close

In this study, the hybrid process between anodization process of aluminum (Al)and photolithography as a top-down process was developed to fabricate self-aligned room-temperature operating single electron transistors. Furthermore, anodization processes of titanium, which is one of valve metals, were controlled to directly form titanium oxide nanotube films on a substrate and they were applied to devices such as a miniaturized gas sensor and a dye-sensitized solar cell (DSC)
Three dimensional design of nanostructures for label-free biosensing

NIWANO Michio, HIRANO Ayumi, KIMURA Yasuo, AONUMA Yuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2008 - 2010

More details Close

The purpose of this study is development of a new biosensing technology based on the combination of silicon nanotechnology and design of bio-interfaces. We have examined formation of artificial bilayer lipid membranes (BLMs)in microfabricated apertures and nanoporous structures. We succeeded in preparation of free-standing BLMs having dramatically improved membrane stability. Such stable BLMs will open up variety of applications. In addition, we have examined efficient formation of nano structures as a new platform for nano-bioelectronics. Our approaches are useful for innovation of novel nano-recognition interfaces and bioelectronics based on the design of nanostructure interfaces.
Development of Receptor Ion Channel Arrays Based on Silicon Microfabrication Techniques

HIRANO Ayumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Young Scientists (B)

Institution: Tohoku University

2007 - 2008
神経シナプス内グルタミン酸計測のためのin situナノセンサーの開発

庭野道夫, 平野愛弓, 木村康男

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 萌芽研究

Institution: 東北大学

2007 - 2008

More details Close

本研究では、ナノメートルスケールのグルタミン酸センサー構築のための基礎検討を目的としている。当初は、酵素グルタミン酸オキシダーゼに基づくセンサー設計を予定していたが、入手可能なグルタミン酸オキシダーゼにはグルタミナーゼが混入しており、脳内に高濃度に存在するグルタミンとの識別が困難であることが判明した。そこで感応素子としては、酵素に比べてより高感度かつ高速応答が見込めるグルタミン酸レセプターチャネルを用いることにした。昨年度は、感応素子のグルタミン酸レセプターのマトリクスとなる平面脂質二分子膜のナノ空間への作製とその安定化を行ったが、平成20年度は、実際に、ラット脳より抽出したグルタミン酸レセプターを膜中に包埋し、そのチャネル応答の記録を試みた。半導体微細加工技術を用いて作製したナノスケールの孔や、ポーラスアルミナナノ構造体中で脂質二分子膜の形成を行い、その中に抽出したグルタミン酸レセプターチャネルを包埋した。この膜のグルタミン酸応答を評価したところ、活性は見られたものの他のチャネルタンパクが混在しており、純度を高めるためのさらなる精製が必要であることが分かった。現在、その精製法について検討中である。また、安定化脂質二分子膜作成の基礎知見を得るために、表面赤外分光を用いた分光学的検討も行い、多重内部反射型赤外分光法(MIR-IRAS)を用いて、シリコン基板上のアガロース支持二分子膜を観察し、脂質溶液から自発的に脂質二分子膜が形成していく過程を、標識を用いることなくその場観察することに成功した(投稿中)。その他、シリコン基板表面上における種々の生体分子反応(DNAのハイブリダイゼーション、抗原抗体反応、細胞死)をMIR-IRASを用いて非標識でその場観察することに成功した。
Surface infrared spectroscopic studies on cellular dynamic processes and the application to cell chips

NIWANO Michio, KIMURA Yasuo, HIRANO Ayumi, MIYAZAKI Hitoshi, ISODA Hiroko, MIZOGUCHI Tsuyoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2005 - 2007

More details Close

In this research, we have developed m situ real-time monitoring method for cell dynamics on the basis of infrared spectroscopy with the multiple internal reflections (MIR-IRAS). Our research projects were focused on (1) development of IRAS method for in situ monitoring of cell growth, (2) development of non-label IRAS detection of cell death and its application to cytotoxic assay. In addition, we also examined non-label detection of biomolecular interactions, such as (3) antigen-antibody interactions and (4) DNA hybridization both in solution phase and at the silicon surfaces. For the development of the real-time monitoring of cell dynamics, we started with construction of cell culture condition in a FTIR sample room. The temperature and humidity in a cell chamber placed in the FTIR sample room was controlled to be 37 °C and >80%, respectively. Since the sample room needs to be purged with air which was free from water and carbon dioxide vapor, a humidified gas mixture containing CO_2 was introduced to the chamber through silicone tubes. By using this apparatus, we have confirmed the cell viability and proliferation of HL-60 cells after 24-h incubation in the chambers. Then the cytotoxic effect by Tween20 was in-situ monitored with MIR-IRAS. It was demonstrated that the cell death can be monitored in-situ by analyzing the amide II peak intensity. In addition, we succeeded in real-time monitoring of the dynamic processes upon apoptosis induction by using MIR-IRAS. We also examined label-free detection of antigen-antibody interactions and DNA hybridization and demonstrated that MIR-IRAS is particularly useful for discriminating specific and non-specific adsorption by careful analysis of spectral features. Thus our method can be applied to in-situ monitoring of various cellular events as well as individual biomolecular interactions as non-label detection method for high-performance cell-chips and bio-chips.
神経伝達物質の領野レベルの濃度分布を可視化するための酵素膜イメージング法の開発

平野愛弓

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 若手研究(B)

Institution: 日本大学

2002 - 2003

More details Close

1.神経伝達物質L-グルタミン酸の脳内分布を知るための方法論を開発することは重要である.以前報告した,グルタミン酸オキシダーゼ(GluOx)-ペルオキシダーゼ(HRP)酵素膜に基づくL-グルタミン酸イメージング法(Anal.Sci.2000,16,25-29)では,L-グルタミン酸の酵素による認識から色素の呈色に至るまでの反応が非可逆的に進行するため,観測される呈色強度は積算放出量に相当し,放出の増減にかかわらず常に増加していた.本研究では,測定時点の発色強度から前時点の発色強度を差し引いた差イメージを各測定時間について算出することにより,単位時間・単位面積当たりのフラックスとしてL-グルタミン酸放出を時間依存的にイメージングすることを検討した.これを,虚血刺激下における海馬スライス内のL-グルタミン酸放出のイメージングに適用し,虚血海馬内で放出されるL-グルタミン酸の領野間分布を時間依存的にイメージングすることに成功した(投稿準備中). 2.上述の酵素膜イメージング法を,神経伝達物質の領野間分布の可視イメージング法として一般化するために,エステラーゼ型酵素をもつアセチルコリンを対象に酵素膜を設計した.脳スライス内には大量のアセチルコリンエステラーゼが存在することを利用し,コリンオキシダーゼとHRPに基づく酵素膜を作成した.この酵素膜について,in vitroのモデル実験系を用いて感度,選択性,応答時間等の観点から評価を行った.現在,マウス脳スライスを用いて刺激によって放出されるアセチルコリンの領野間分布の時間依存的イメージングについて検討中である.

Show all Show first 5

Social Activities 9

栃木県立宇都宮女子高等学校出張講義

2019/01/26 - 2019/01/26
山形県立山県西高等学校出張講義

出張講義

2016/07/21 - 2016/07/21
薬の副作用を見つける半導体チップ

2016/02/20 -
私立女子学院高等学校「卒業生の話を聞く会」

2014/01/09 -

More details Close

高１を対象の「卒業生の話を聞く会」で理系に進んだ卒業としてキャリア形成や、大学での研究内容について、わかりやすく解説した。
福島県立会津学鳳高等学校出前授業

2013/10/11 -

More details Close

バイオセンサをはじめとする医工学の最先端の研究について、高校生にわかりやすく解説することを通じて、工学の魅力、楽しさを啓発する。
群馬県立高崎女子高等学校出前授業

2012/11/29 -

More details Close

大学模擬授業を行い、女子高生の理数系教育プログラムに役立てる
宮城県立宮城第一高校学校出前授業

2012/11/01 -

More details Close

宮城県立宮城第一高校学校が主催する大学学部紹介「ミヤイチキャンパス」における学部紹介および模擬授業
群馬県立高崎高等学校出前授業

2010/10/15 -

More details Close

群馬県立高崎高校主催大学教員による出張授業
群馬県立太田高等学校出前授業

2009/10/03 -

More details Close

群馬県立太田高校主催の大学教授による出張授業

Show all Show first 5

Other 10

微細加工シリコン基板に基づく水溶液中動作型脂質二分子膜デバイスの創成

More details Close

本研究では，申請者らが提案してきた安定化脂質二分子膜に基づき，その膜中にイオンチャネルタンパク質を包埋することにより，新しい高機能バイオセンシングデバイスの創成を行う．具体的には，近年，薬物による副作用性不整脈の観点から注目を集めている心筋のKチャネル（hERGチャネル）を膜中に包埋することにより，hERGチャネルに対する副作用を高効率に評価できる薬物副作用評価系の構築を行う．また，これまでにない新しい試みとして，脂質二分子膜中にチャネル形成材料として金属ナノ粒子を包埋して電子ナノチャネルを創成し，これに基づく水溶液中動作型電子デバイスの構築についても検討する．これにより，従来の固体エレクトロニクスとは全く異なるnanofluidic bioelectronicsという新しい分野の創成を目指す．
CREST「超絶縁性脂質二分子膜に基づくイオン・電子ナノチャネルの創成」

More details Close

本研究では，細胞膜の基本構造となる脂質二分子膜の特徴の(1)ナノ絶縁性の流動膜であることや，(2)脂質分子の自己集合により容易に形成できることに着目し，脂質二分子膜内でのイオンおよび電子ナノチャネルの創成を目指します．チャネル形成材料としてイオンチャネルタンパク質や金属ナノ粒子，半導体ナノ粒子等を膜内に包埋することにより，脂質二分子膜中にイオンや電子が縦方向および横方向に通過できるようなナノチャネルを創成し，水溶液中で動作する高感度な種々の化学・物理センサの構築を行います．
hERGチャネル組込シリコンチップに基づく薬物副作用評価に関する研究

More details Close

本研究では，hERGチャネルタンパク質への医薬品の副作用評価を評価するための新しい方法について，hERGチャネル組込人工脂質二分子膜を用いて構築し，種々の副作用薬物についてその作用を評価して，現行法のパッチクランプ法の値と比較する．人工膜再構成系に基づく副作用評価hERGチャネルチップについて，精度，信頼性，歩留まり，得られる情報の信頼性，の観点から評価し，新しい副作用評価法として提案する．
人工脂質二分子膜に基づくhERGチャネルアレイの構築とhigh throughput副作用評価チップへの応用

More details Close

平成21年，厚生労働省は，全候補薬品に対し，心筋のhERGチャネルに対する安全性をin vitroでのチャネル電流側定によって評価することを義務付けた．このチャネルは薬物に非常に敏感で，死亡例を含む重篤な副作用を数多く引き起こしたからである．このような背景を受け，現在，イオンチャネルに対する高効率な薬物スクリーニング系への重要が高まっている．人工脂質二分子膜は，薬物スクリーニング系のプラットフォームとして期待が高いが，機械的強度が極めて低く，その発展の障害となっていた．我々は最近，ナノ構造体や半導体加工技術と脂質二分子膜形成の融合により，機械的強度の高い脂質二分子膜の構築に成功した．さらに作製したチップを低誘電率の絶縁材料で被覆することにより，電気特性の問題（ノイズ電流および過渡応答特性）を解決した．次の段階としては，この安定化脂質二分子膜にイオンチャネルを組込み，薬物スクリーニングのためのイオンチャネルチップへと展開することであるが，安定な脂質二分子膜ではチャネルの組込確率が低いという新たな課題に直面している．そこで，本研究では，安定化人工脂質二分子膜へのイオンチャネルの効率的組込法について検討し，これに基づいて，チャネル包埋二分子膜をアレイ状に並べたイオンチャネルチップを，hERGチャネルを対象に構築する．hERGチャネルアレイに基づく新薬開発のための新規な副作用評価ツールとして提案する．
安定化人工脂質二分子膜へのイオンチャネル包埋過程に関する基礎研究

More details Close

イオンチャネルは創薬における主要ターゲットの一種であり，イオンチャネルの薬物応答を高効率に評価する方法の開発が望まれている．細胞膜構造を模した人工平面脂質二分子膜にイオンチャネルを包埋した再構成系は，化学的制御系においてチャネルへの薬物作用が評価できる特徴をもつ．本研究では，申請者が最近報告した安定化人工脂質二分子膜に効率良く生体イオンチャネルを包埋するための化学的および物理的手法の検討を行い，イオンチャネル包埋脂質二分子膜センサーを構築するための基礎とすることを目的としている．イオンチャネルはリポソームに包埋された状態で抽出されるため，イオンチャネルの包埋促進のためには，リポソームの二分子膜中への膜融合を促進する必要がある．そこで本研究では，膜融合促進ペプチドや誘電泳動などを用いて一過性の化学的および物理的摂動を二分子膜に与えることにより膜融合の促進について検討し，安定性の高い膜ならではのタンパク質組み込み法を提案する．
イオンチャネル発現昆虫細胞株の樹立

More details Close

脂質二分子膜イオンチャネルセンサの構築に必要なイオンチャネルタンパク質の取扱量を増やすため、比較的大量発現が可能といわれる昆虫細胞培養系の樹立を共同で行っている。
さきがけ「ナノ形状設計に基づく人工神経細胞膜センサーの創製と機能発現」

More details Close

生体の自己組織化薄膜である脂質二分子膜を半導体加工技術と融合し，そこに脳組織より抽出した神経伝達物質レセプターチャネルを組込むことにより，人工神経細胞膜センサーを創製する．従来の人工細胞膜はその機械的強度に問題があり，バイオセンサー開発の障害となってきた．本研究では，nmスケールで形状を制御した微細孔をトップダウン技術により作製し，その中で脂質分子の自己集合プロセスによって二分子膜を形成することにより，人工膜系最大の問題であった機械的脆弱性の問題を解決する．さらに，その膜中にレセプターチャネルを埋め込むことにより，人工的にシナプス後膜構造を構築し，脳内計測を目指したプローブ型センサーの開発や高効率薬物スクリーニング法のためのイオンチャネルアレイを構築する．また，実際の神経細胞とのシナプスを形成することにより，神経前膜機能を評価する人工後膜デバイスとしての応用についても検討する．ナノ構造と人工神経細胞膜とを融合した本デバイスは，脳機能解析のみならず，神経細胞と集積回路の接合部としての応用可能性ももつため，様々な分野での発展が期待される次世代ナノバイオデバイスとなる．
ナノポーラス構造を用いた平面脂質二分子膜の安定化とそのイオンチャンネルセンサーへの応用

More details Close

平面脂質二分子膜中にレセプターイオンチャンネル蛋白質を包埋したイオンチャンネルセンサーは，神経伝達物質を高感度かつ高選択的に検出できるセンサーとして重要である．しかし，イオンチャンネル蛋白質がその機能を発現できる唯一のマトリクスである脂質二分子膜は，物理的に脆弱であり，イオンチャンネルセンサーの一般化への障害となってきた．本研究では，ポーラスシリコンやポーラスアルミナを用い，ナノメートルスケールの孔の中に平面脂質二分子膜を作成することにより，安定な脂質二分子膜の作成法を開発する．さらに，安定化された脂質二分子膜中に，ラット脳等より抽出・精製したレセプターチャンネル蛋白質を包埋することにより，物理的安定性と高感度・高選択性を兼ね備えたイオンチャンネルセンサーを開発する．
神経伝達物質の多成分同時定量のためのイオンチャンネルアレイの開発

More details Close

脳内において重要な役割を担っている神経伝達物質を多成分同時に定量するためのイオンチャンネルアレイを、半導体微細加工と平面脂質二分子膜法との融合により開発する。
NMDA型グルタミン酸レセプター分子種のイオン透過量の定量

More details Close

NMDA型グルタミン酸レセプターの4種分子種（epsilon1-4/zeta1）の全てについて、発現細胞から抽出し、平面脂質二分子膜に再構成し、種々のアゴニストが1個のチャンネル分子種に対して誘起するイオン透過量を定量した。

Show all Show first 5