Vol. 23, Supplement A (2007)

Abstracts

銀薄膜を用いた極微小領域の２次元ＳＰＲバイオセンシング

富山大院理工，NTT-AT

大島豊弘，入部康敬，飛田達也，○鈴木正康

Two Dimensional SPR Biosensing in Micro Area by Using Silver Membrane

Toyohiro OHSHIMA, Yasunori IRIBE, Tatsuya TOBITA, Masayasu SUZUKI

Graduate School of Science and Engineering, University of Toyama,
Toyama-shi, Toyama 930-8555, Japan
NTT Advanced Technologies Corporation, Atsugi-shi, Kanagawa 243-0124, Japan

We are developing the lymphocyte micro array chip system for the screening of antigen-specific B lymphocytes, which are necessary for the development of antibody medicines. We focused on a two-dimensional surface plasmon resonance imaging sensor (2D-SPR) as a tool for immunochemical monitoring in the 10μmΦ micro-well. But the SPR sensitivity is decreased in very small area under 10 μmΦ. Shorter wavelength light source might be suitable for solving this problem. Silver thin film was used for the SPR sensor chip, because silver shows good SPR even the wavelength of the light source is shorter than 600nm.
In order to protect silver film from buffered saline, the partially oxidized aluminum film or SAM layer of PEG6-COOH alkanethiol was prepared on the silver film. Protein A was immobilized onto the SAM layer as affinity ligand for IgG. IgG could be detected in 8.5 μmΦ micro wells by using a silver film. By the use of 505 nm light source, sensitivity decrease in micro area could be further suppressed.

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2次元SPR装置による肥満細胞の抗体結合反応と特異的抗原応答のイメージング

富山大院理工

○堀井雅恵、篠原寛明、入部康敬、鈴木正康

Real-time Imaging of Mast Cells Stimulated by Antibody Binding and the Subsequent
Specific Antigen Binding, Using a 2D-SPR System

Masae HORII, Hiroaki SHINOHARA, Yasunori IRIBE, Masayasu SUZUKI

Graduate School of Science and Engineering, University of Toyama,
Toyama-shi, Toyama 930-8555

Surface plasmon resonance (SPR) biosensor has some advantages such as label-free, real-time and high-sensitive measurement. Newly developed two-dimensional SPR (2D-SPR) system can further obtain 2D image of bio affinity binding reactions in 10 μm resolution. Therefore it is expected to be available for individual observation of multi-cell responses. In this paper, we examined to observe the response of a mast cell model, rat basophile leukemia cell (RBL-2H3) upon stimulation with IgE and the subsequent allergen, by using the 2D-SPR imaging system. IgE (anti-dinitorophenyl) induced the increment of reflection intensity of RBL-₂H₃ cell on the 2D-SPR image at 0.1 μg/mL or more even if in the absence of antigen. Furthermore, responses of RBL-₂H₃ cells, which were pre-sensitized with 0.1 μg/mL anti-DNP IgE, were observed on the 2D-SPR image at real-time upon 1〜100 ng/mL DNP-BSA (bovine serum albumin) stimulation.

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ベンズアルデヒド検出のためのSAM膜を用いた高感度で安定なSPR免疫センサ

九大産学連携センターa、九大院農b、九大院情シc、インセントd

　○K. V. Gobia、松本 清b、都甲 潔c、池崎 秀和d、三浦 則雄a

Highly Sensitive and Stable Self-Assembled Monolayer Based Surface Plasmon Resonance (SPR) Immunosensor for Detection of Benzaldehyde

OK. Vengatajalabathy GOBI,^a Kiyoshi MATSUMOTO,^b Kiyoshi TOKO,^c
Hidekazu IKEZAKI,^d Norio MIURA^a
a Art, Science and Technology Center for Cooperative Research (KASTEC),
Kyushu University, Kasuga-shi, Fukuoka 816-8580
^b Graduate School of Agriculture, Kyushu University, Fukuoka 812-8581
^c Graduate School of Information Science and Electrical Engineering,
Kyushu University, Fukuoka 812-8581
^d Intelligent Sensor Technology Incorporation (Insent), Atsugi-shi, Kanagawa 243-0032

Development of a highly stable and regenerable SPR immunosensor for detection of trace amounts of a small molecular fragrant, benzaldehyde (BZ), has been demonstrated. The sensing surface was fabricated by self-assembling of long-chain polyethyleneglycol (PEG) alkanethiols on the surface of SPR-active Au films, followed by chemical coupling with a BZ analogue. The BZ-capped PEG thin-film is highly resistive to non-specific binding with proteins and shows strong affinity with anti-BZ antibody. An indirect inhibition immunoassay principle has been applied for detection of BZ, and the present immunosensor can measure the BZ concentration as low as 100 ppt (pg/ml). An add-on strategy involving Au nanoparticles encapsulated with secondary antibodies has been used to enhance the sensor signal, with which the low-detection-limit of the immunosensor is improved to 10 ppt with a total response time of ca. 10 min.

 

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マルチチャンネルフローセルを用いたポータブルSPR免疫センサによる2,4-Dの検出

九大院総理工^a, 九大産学連携センター^b, オムロン^c, 九大院薬^d

○ S. J. Kim^a, K. V. Gobi^b, 岩坂博之^c, 田中宏幸^d, 三浦則雄^b

Evaluation of a Portable SPR Immunosensor Equipped with Multichannel Flow-Cell for Detecting 2,4-D

○ Sook Jin KIM^a, K. Vengatajalabathy GOBI ^b, Hiroyuki IWASAKA ^c, Hiroyuki TANAKA^d, Norio MIURA^b

^aInterdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580
^bArt, Science and Technology Center for Cooperative research (KASTEC), Kyushu University, Kasuga-shi, Fukuoka 816-8580
^cOmron Corp., Kusatsu-shi, Shiga 525-0035
^dGraduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582

A newly-developed miniature surface plasmon resonance (SPR) instrument equipped with an 8-channel microfluidic sensor chip has been examined to detect a low-molecular-weight (lmw) analyte, 2,4-dichlorophenoxyacetic acid (2,4-D). As a detection principle for determination of 2,4-D, an indirect competitive immunoassay was applied to the present sensing system, which assures the detection of lmw compounds. The extent of 2,4-D-mAb binding on the sensor surface, that has been functionalized by simple physical adsorption of 2,4-D-BSA, is inhibited by the presence of 2,4-D, and the SPR angle response is inversely correlating to the logarithm of concentration of 2,4-D. With the newly-designed multichannel chip and compact SPR instrument, picomolar (sub ppb) level of 2,4-D in 8 different samples could be determined simultaneously within a response time of only 5 min. The present sensor showed negligible cross-sensitivity against several environmental pollutants structurally resemblant to 2,4-D and no interference for 2,4-D determination in spiked river-water samples.

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マイクロ流路中のプラズマを用いた元素分析の安定化

北陸先端大院大、マイクロエミッション、JST

○熊谷績、山本保、民谷栄一、高村禅

Stabilization of the Elemental Analyzer Using Plasma in Micro Channel

Isao KUMAGAI^a , Tamotsu YAMAMOTO ^b , Eiichi TAMIYA^a and Yuzuru TAKAMURA^a,c

^a School of Materials Science, Japan Advanced Institute of Science and
Technology,1-1 Asahidai, Nomi-shi, Ishikawa 923-1292b Micro Emission, Inc.

18-20 Sumiyoshimachi, Nonoichimachi, Ishikawa-gun, Ishikawa 921-8813c Japan
Science and Technology Agency(JST) PRESTOKawaguchi Center Building4-1-8,
Honcho, Kawaguchi-shi, Saitama 332-0012

A handy analyzer for heavy metal detection using plasma in micro channel is developed. The micro channel is filled with sample solution, and a high voltage is applied. Subsequently, a bubble is generated in the narrow part of the channel, and plasma emits light in the bubble. It is important to generate the bubble at a fixed position for quantitative analysis. This research optimized the micro channel shape by numerical simulation of temperature and nucleation frequency. In addition, experimental work was also done for observing the generation the bubble. As a result, this nucleation position is successfully controlled at the center of the micro channel shape.

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キャピラリーアセンブルドマイクロチップ系への電気化学測定モジュールの
導入と過酸化水素、グルコースの測定

兵庫県大院物質理

○稲積伸悟、久本秀明、水谷文雄

A Capillary-Assembled Microchip with an Electrochemical Detection System

Shingo INADUMI, Hideaki HISAMOTO and Fumio MIZUTANI

Graduate School of Material Science, University of Hyogo,3-2-1 Kouto,
Kamigori, Hyogo 678-1297

A pair of platinum electrodes encapsulated in square capillaries (300 μm × 300 μm) and a glucose oxidase (GOx)- attached square capillary (300 μm × 300 μm) were embedded on a lattice microchannel network on a poly (dimetylsoloxane) plate to construct a micro-flow system for measuring the enzyme substrate, glucose. The GOx in the enzyme capillary oxidized glucose to generate hydrogen peroxide, and the concentration of the hydrogen peroxide was measured amperometrically on the platinum working electrode. The current response was proportional to the glucose concentration up to 1 mM. The principle of combining plural square capillaries with individual functions to construct a capillary-assembled microchip (CAs-CHIP) was thus successfully applied to the electrochemical determination of the enzyme substate.

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送液機構と電気化学センサを集積化した微小化学分析チップ

筑波大院数理物質

○佐藤航、横幕浩臣、齋藤靖明、細野裕樹、アパジャー・サンジェイ、鈴木博章

Highly Sophisticated Electrochemical Analysis System with an Integrated Microfluidic
System and Electrochemical Sensors

Wataru SATOH, Hiroomi YOKOMAKU, Yasuaki SAITO, Hiroki HOSONO,
Sanjay UPADHYAY, and Hiroaki SUZUKI

Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-
8573

An integrated device which can conduct timely transport of a sample solution and analyze its components was constructed. The transport of solutions was based on capillary action on hydrophilic glass areas and the control by valves which operate based on electrowetting. Electrochemical sensors for glucose, lactate, GOT, GPT, pH, ammonia, urea, and creatinine were integrated. Sensors for the former four were amperometric whereas the detection of the latter four was based on potentiometry. The sensors for GOT and GPT had a freeze-dried substrate matrix to realize rapid mixing. The ammonia, urea, and creatinine sensors had an air gap structure to realize a fast response. The sample solution was transported to required sensing sites at desired times. The integrated sensors showed distinct responses upon the introduction of a sample solution. Linear relationships were observed between the output signals and the concentration or the logarithm of the concentration of the analytes.

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バイオリソグラフィー技術のセンサ応用

東北大院工

○西澤松彦

Biolithography and Biosensing

Matsuhiko NISHIZAWA

Graduate School of Engineering, Tohoku University,
Aramaki-Aoba, Sendai 980-8579

The interfacing between biomolecules and materials is one of the most important subjects for both in-vitro and in-vivo biomedical devices. We have been studying the potential use of microelectrode techniques as the tool for surface bio-micromachining, and developed original techniques for controlling bionic interfaces. Our patterning technique named "electrochemical bio-lithography" is simple enough to be integrated to the small and closed systems such as microfluidic devices. Furthermore, the technique　can be conducted under typical physiological conditions and thus enables the multi-micropatterning with different kinds of cells. The in situ navigation of cellular migration is also possible. In addition to the micropatterning of proteins and cells, a technique for in-situ formation of microcircuit with conducting polymers has been developed as a potential interface to cellular networks.

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○飯田泰広・高原悠佳里・佐藤生男

Screening of Enzyme Inhibitors with Use of an Immobilized Enzyme as a Recognition
Element

Yasuhiro IIDA, Yukari TAKAHARA, and Ikuo SATOH

Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute
of Technology
1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken, 243-0292, Japan

A novel screening method based on an FIA was developed for tyrosinase inhibitors with use of an immobilized tyrosinase as a recognition element. Tyrosinase is a key enzyme for melanin biosynthesis in pigment cells. Melanin is a dark polymeric pigment which causes skin pigmentation, and therefore, new or more active inhibitors of tyrosinase are required as whitening effectors. In this study, we developed the screening system in combination with the FIA system and the immobilized tyrosinase and applied the system to estimation of inhibition activities of herbal extracts against the tyrosinase column. As a result of the screening, use of the proposed an FIA system demonstrated that 50 % ethanol extracts of 4 among 32 herbal medicines tested showed high inhibitory effect against tyrosinase activity. On the other hand, a kojic acid, known as an inhibitor of tyrosinase, functioned indeed as the inhibitor, however, recovery of tyrosinase activity was revealed. These results indicated that this inhibition effect should be temporary. Thus, we exemplified that this FIA system should be an effective screening system for enzyme inhibitors containing tyrosinase inhibitor.

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使い捨て型を目指したプラスチックシート状酵素センサの作製


東洋大学^a、国立リハビリ研^b

○高橋健一^a、宇佐美論^a、加藤誠志^b、外山滋^b

Fabrication of Plastic Film-Based Enzyme Sensor Aimed at Disposable Use

Kenichi TAKAHASHI^a, Ron USAMI^a, Seishi KATO^b, and Shigeru TOYAMA^b

^aDepartment of Chemical Engineering, Faculty of Engineering, Toyo University, 2100 Nakanodai, Kujirai, Kawagoe-shi, Saitama 350-8585
^bResearch Institute, National Rehabilitation Center for Persons with Disabilities, 4-1 Namiki, Tokorozawa-shi, Saitama 359-8555

An enzyme sensor chip has been developed on a plastic film. The sensor chip has not only the sensor electrode, but counter and reference electrodes. This time, the reference electrode holds internal liquid so that the constant potential is applied on the sensor electrode even if the concentration of Cl^- ion in sample solution changes. The sensor exhibited glucose concentration-dependent response, and it was not affected by the Cl^- concentration.

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共有結合型分子インプリントポリマーのゲート効果を利用したグルコースセンサの開発

芝浦工大

〇成松 明哲、関根 真一、吉見 靖男

Glucose Sensor Using Gate Effect of Thin Layer of Covalenly Molecularly Imprinted
Polymer

Akisato NARIMATSU, Shin-ichi SEKINE, Yasuo YOSHIMI

Department of Applied Chemistry, Shibaura Institute of Technology,
Koto-ku, Tokyo, 135-8548

　The final purpose of this work is development of an enzyme-free glucose sensor using gate effect of molecularly imprinted polymer (MIP). Gate effect is change in solute diffusive permeability of MIP by specific interaction with its template. Glucose bound covalently with 4-vinylphenyl boronic acid by azeotropic distillation of pyridine. The compound copolymerized with crosslinking monomer N, N' methylene-bis-acrylamide with grafting onto indium-tin oxide (ITO). The faradic current of ferricyanide at the grafted ITO electrode was sensitive to glucose concentration ranging 1-10 mM. The range corresponds to level of healthy blood sugar.

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11.

有機単分子層修飾FETによるDNAミスマッチ検出

早大理工¹、早大科健機構²

○伊藤健太郎¹、松永真理子¹、笹野順司²、逢坂哲濔^1,2

Detection of DNA Mismatch Using Organic Monolayer Modified Field Effect Transistor

Kentaro IT¹O, Mariko MATSUNAGA¹, Junji SASANO² and Tetsuya OSAKA^1,2

Department of Materials Science and Technology, Graduate School of Engineering and Science, Waseda University¹
shinjuku-ku, Okubo3-4-1, Japan
Consolidated Research Institute for Advanced Science and Medical Care, Waseda University²
Shinjuku-ku,Waseda Ttsurumaki-Cho 513, Japan

Single nucleotide polymorphisms (SNPs) in DNA sequences are reported to influence on personal differences in constitution. Thus, highly sensitive analyzing method for SNPs is considered to be useful for diagnostic test. In this study, we focus on field effect transistor (FET) because of high sensitivity and easiness for integration with other systems. A single strand probe DNA was immobilized on the gate surface using glutaraldehyde as a crosslinker to an organic monolayer of 3-aminopropyltriethoxisilane(APTES) formed on the gate oxide of FET. Then, the gate was immersed in the solutions of various target DNAs such as complementary DNA and one base mismatch DNA. Before and after hybridization, currnt between drain and source of the FET was measured versus gate voltage. As a result, threshold voltages were found to change and the complementary DNA changed it much more than one base mismatch DNA. In addition, we found that threshold voltage changed depending on the position of mismatch.

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^a東京工科BS，^b産総研バイオニクス研究センター

中村秀明^a,b，○鈴木教太^a，小林瞬^a，平田雄^a，大桃智貴^a，茂木陽太郎^a，阿部雄太^a，奥間政作^a，家高光敏^a，小泉 留衣^a，輕部征夫^a,b

An Optical Biochemical Oxygen Demand Determination Method Using DCIP as the Electron Acceptor and Eukaryote Saccharomyces Cerevisiae

Hideaki Nakamura^a,b， Kyota Suzuki^a， Shun Kobayashi^a， Yu Hirata^a，Tomoki Ohmomo^a， Yotaro Mogi^a，
Yuta Abe^a， Seisaku Okuma^a，Mitsutoshi Yataka^a，Rui Koizumi^a， Isao Karube^a,b

^aSchool of Bionics， Tokyo University of Technology，1404‐1 Katakura，Hachiouji，Tokyo 192‐0982，Japan

^bResearch Center of Advanced Bionics（RCAB)， National Institute of Advanced Industrial Sience and Technology （AIST)，1404‐1 Katakura，Hachiouji，Tokyo 192‐0982，Japan

An optical biochemical oxygen demand （BOD） determination method was established with highly sensitivity and reproducibility by employing 2,6‐dichlorophenolindophenol （DCIP） as a redox color indicator, yeast Saccharomyces erevisiae, and a temperature controlling system providing a three consecutive stir units. The absorbance of DCIP decreased due to the metabolism of organic substances in aqueous samples by S．cerevisiae. First,the measuring conditions were optimized. Under the optimum conditions, a calibration curve for glucose glutamic acid concentration was obtained between 1.1 to 22 mg O₂ ／L （r = 0.988， 6points, n ＝ 3） when using a 10 min incubation of the reaction mixture at 30℃. The reproducibility of the sensor responses in the calibration curve was 1.77％ （average of relative standard deviations； RSDav). Subsequently, the characterization of this method was studied and no influence of the heavy metal ions （1．0 mg／L Fe³⁺, Cu2⁺, Mn²⁺, Cr³⁺, Zn²⁺) was observed and stable responses were obtained for 36 days when the yeast suspension was stored at 4℃ （response reduction, 89％； RSDav value for nine testing days at three repetitive measurements, 0.768%）. Results on real sample measurements would present in this conference.

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高感度チロシナーゼバイオセンサ作製におけるカチオン性有機色素の効果

埼玉工大工　　

○長谷部　靖, 福沢 みちる, 川窪 君江

Effect of Cationic Organic Dyes on the Preparation of Highly Sensitive Tyrosinase
Biosensor

Yasushi HASEBE, Michiru FUKUZAWA, Kimie KAWAKUBO

Department of Applied Chemistry, Saitama Institute of Technology,
1690 Fusaiji, Fukaya-shi, Saitama 369-0293

Tyrosinase (TYR) and methylene blue (MB) were simultaneously co-adsorbed from a TYR/MB mixed solution onto a glassy carbon electrode (GCE) to fabricate a highly sensitive amperometric biosensor. The cathodic current response to catechol obtained by the TYR and MB-coadsorbed GCE (TYR/MB-GCE) increased with increasing the concentration of MB in the TYR/MB-mixed solution. The CV and impedance measurements revealed that the MB prevents an inactivation of the TYR on the GCE surface. The sensitivity of the TYR/MB-GCE decreased with increasing buffer concentration and ionic strength of the TYR/MB-mixed solution. Other cationic dyes such as acridine orange and meldra's blue showed similar effect. These results suggest that electrostatic interaction between cationic organic dyes and anionic TYR (pI = 4.9) is important to retain the activity of adsorbed-TYR on the GCE surface. The resulting TYR/MB-GCE enabled highly sensitive detection of catechol with a rapid response time (< 5 s) at! 0 V vs. Ag/AgCl. The calibration curve for catechol by the TYR/MB-GCE was linear in the concentration range from 10 nM to 50 μM. The TYR/MB-GCE retained ca.50 % of its original activity after the 5 days storage in 0.1 M phosphate buffer (pH 5.0) at 4℃.

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金ナノ構造制御界面を用いた表面プラズモン共鳴センサによるTNTの超高感度検出


九大産学連携センター^a、学振^b、九大院総理工^c、九大院農^d、九大院情シ^e

○川口俊一^a、D. R. Shankarana^a,b、S. J. Kim^c、松本 清^d、都甲 潔^e、三浦則雄^a

Strategy for Ultra-Highly Sensitive TNT Detection Using Nano-Controlled Surface on SPR Sensor

○Toshikazu KAWAGUCHIa, Dhesingh RAVI SHANKARANa,b, Sook-jin KIMc,
Kiyoshi MATSUMOTOd, Kiyoshi TOKOe, Norio MIURAa

^a Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^b Japan Society for the Promotion of Science, Tokyo 102-8471
^c Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^d Graduate School of Agriculture, Kyushu University, Fukuoka-shi 819-0395
^e Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka-shi 812-8581

We　report here the SPR immunosensor for a highly sensitive detection of explosive compounds. The novel immunosurface was prepared by a nano-fabrication technique which utilized self-assembly (SA) of thiolate compound onto Au nanoparticle. It succeeded to control the distribution of Au nanoparticle (10 nm) on the dithiolate modified surface without heterogeneous aggregation. The Au nanoparticles formed grain structure (grain diameter: 40-60 nm) under flow condition. Surface concentration of Au nanoparticle was controllable with a duration time of flow and the solution concentration of Au nanoparticle. TNPh-β-alanine was immobilized on the sensor surface via amine-terminated thiolate on the Au nanoparticles for detection of TNT by indirect competitive inhibition. The obtained immunosurface could be used repeatedly by regenerating active sensor surface using pepsin-HCl solution. The observed resonance-angle shift was up to three times higher than that of our previous report. In addition, the present immunosensor fabricated with Au nanoparticle could measure the tiny amount (in ppt-level) of TNT faster than that without gold nanoparticle.

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病院内の空気環境改善のためのバイオマーカーを用いた官能検査

富山大学 工学部

○高阪翔士、榊間城作、中林美奈子、山口昌樹

Sensory Test Using Biomarker for Air Environment Improvement in Hospital

Shoshi KOSAKA, Josak SAKAKIMA, Minako NAKABAYASHI and Masaki YAMAGUCHI

Faculty of Engineering, University of Toyama,　3190 Gofuku, Toyama, 930-8555 Japan

The purpose of this study is to establish an evaluating methodology of discomfort effect of odor by using biochemical marker such as salivary amylase. The odor evaluating device consists of an odor presentation dome, three sets of metal oxide semiconductor-type gas sensor, a nebulizer, a sofa and a personal computer for data collection. Five healthy young male adults were used as the subjects. Ethanol and ammonia were used as olfactory stimuli in order to evaluate the air environment in hospital. In ethanol, no significant difference in sAMY were observed before, during and after inhalations both 10 and 50 ppm.
In ammonia, a significant difference in sAMY were observed before, during and after inhalations when 5 ppm. It was considered that the influence of kind and concentration of odor might be quantitatively evaluated using the odor evaluating device.

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マイクロpHスタットを用いたプロテアーゼ活性測定システムの構築

筑波大院数理物質

○森本克也、戸谷真理子、福田淳二、鈴木博章

Development of a Micro Analysis System for the Determination of Protease Activity
Using a Micro pH-Stat

Katsuya MORIMOTO, Mariko TOYA, Junji FUKUDA, and Hiroaki SUZUKI

Graduate School of Pure and Applied Sciences, University of Tsukuba,Tsukuba,
Ibaraki 305-8573

A protease assay based on a pH-static titration was realized using a micro pH-stat. The operation was based on an irregular use of the three-electrode system, which caused a negative feedback accompanying a potential shift of the reference electrode. As a result, the pH of the reaction chamber was maintained at a constant value. The charge generated in the titrating process could be related with the amount of protons produced or consumed. The device could be used for the determination of protease activity at a low pH. While the pH-stat was operating, the produced hydroxide ions originating from the hydrolytic reaction were constantly titrated resulting in a gradual increase in the generated charge. A linear relationship was observed between the initial rate of charge increase and the activity of pepsin.

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分子鋳型膜を修飾したマイクロ電極によるコレステロールの選択的検出

阪府大 先端セ

松本 洋昭，○深澤 聡，椎木弘，長岡 勉

Cholesterol-Selective Detection by Using Molecularly Imprinted Self-Assembled
Monolayer Microelectrodee

Hiroaki Matsumoto, Satoshi Fukazawa, Hiroshi Shiigi, Tsutomu Nagaoka

Frontier Science Innovation Center, Osaka Prefecture University,
1-2 Gakuen-cho, nakaku Sakai 599-8570

Control of the total cholesterol level in the body plays an important role for preventing life-style related diseases. Now, the measurement of cholesterol level in the clinical institution is carried out by using absorption photometer with the enzymatic reaction. However, the conventional method is troublesome due to the necessities of going to a hospital for invasive-collecting blood and using the enzyme reaction through many procedures. On contrary, about 11 % of the body's cholesterol is found in the skin at the same rate as in blood, according to the United States FDA. Therefore, we focus on a simple electrochemical detection and non-invasive measurement of skin cholesterol using the molecularly imprinted self-assembled monolayer microelectrode (MISAM).

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分子認識ポリマーと電気化学測定によるBisphenol A の検出法の検討

創価大工

○横田　宣之, 横山　紘幸, 渕脇　雄介, 久保　いづみ

Study of the Detection System for the Bisphenol A Based on Molecularly Imprinted
Polymer and Electrochemical Detection

Nobuyuki YOKOTA, Hiroyuki YOKOYAMA, Yusuke FUCHIWAKI, Izumi KUBO

Faculty of engineering, Soka University　
1-236 Tangi-cho , Hachiouji ,Tokyo

A sensing system of bisphenol A (BPA) based on molecularly imprinted polymer (MIP) and the electrochemical detection was investigated. MIP for BPA was polymerized thermally from 4-vinylpyridine as a functional monomer and EDMA as a cross-linker and served to prepare a MIP packed column. BPA in an aqueous solution was adsorbed to MIP packed column and eluted by acetonitrile/phosphate buffer (60/40,v/v). From aqueous solution, BPA was adsorbed to the column and eluted completely in the eluent. The eluted BPA was electrochemical detected by cyclic voltammetry. Optimum pH and scan rate were 7.0 and less than 0.1V/s on electrochemical detection of BPA in phosphate buffer. Electrochemical detection of BPA in acetonitrile/phosphate buffer (60/40,v/v) was performed, and linear relation ship between BPA and anodic peak current was observed at the range of 0.01-0.1mM. At last BPA was detected in the sensing system composed of the MIP packed column and electrochemical detection. In the eluent, anodic peak of BPA was observed around 650mV. It was shown that BPA in aqueous solution is able to be detected with the proposed sensing system.

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分子インプリント薄膜のゲート効果に与える鋳型／機能性モノマー結合能の影響

芝浦工大 , 英クランフィールド大

○吉見靖男 , 砂山昌史 , 関根真一 , セルゲイ ピレツキー

Influence of Binding Energy between Template and Functional Monomer on Gate
Effect of Molecularly Imprinted Polymer

Yasuo YOSHIMI, Masahi SUNAYAMA , Shin-ichi SEKINE, Sergey A. PILETSKY

Department Applied Chemistry, Shibaura Institute of Technology,
Koto-ku, Tokyo 135-8548
AND
Institute of BioScience and Technology, Cranfield University, Silsoe,
Bedfordshire, MK45 4DT, UK

The gate effect is change of diffusive solute permeability in molecularly imprinted polymer (MIP) by specific interaction with its template. The topic of this paper is specification of relationship between the gate effect and binding energy of the template−functional monomer. The binding energy between the functional monomer and D-(or L-) phenylalanine anilide (PAA) was calculated by molecular modeling software. The degree of gate effect is determined by cyclic voltammetry of ferrocene at MIP-grafted electrode. The clear relationship was not observed between the degree of the gate effect and the calculated binding energy.

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三次元マイクロアレイ電極による微粒子のマニピュレーションと電気化学的検出

東北大院環境科学

○國方亮太、安川智之、北川雄介、高橋康史、珠玖仁、末永智一

Manipulation of Microperticles Using the 3D Microarray Electrode Based on Positive
Dielectrophoresis

Ryota KUNIKATA, Tomoyuki YASUKAWA, Yusuke KITAGAWA, Yasufumi TAKAHASHI, Hitoshi SHIKU, and Tomokazu MATSUE
Graduate School of Environmental Studies, Tohoku University, Sendai

For the manipulation of microparticles, positive dielectrophoresis was ultilized. AC electric fields were applied to selected column and row bands with same amplitude(20 V_p-p) and frequency(90 kHz) in opposite phase. On the other hand, the other bands were connected to ground, The regions with high electric fields were developed at intersections. Under the AC electric field in a lower frequency region(〜100 kHz), the polystyrene microparticles experience repulsive force positive dielectrophoresis and quickly move in the microparticles experience repulsive force positive dielectrophoresis and quickly move in the direction of strong electric fields. When AC electric fields were applied, the particles were moved and trapped at intersection between in selected column and row bands within 5 sec. Selection of bands appoied to AC signal allows to trapping of microparticles at an objective position.

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21.

自動混合機構とpH調節機構を集積化した電気化学発光分析システム

筑波大院数理物質

○佐藤航, 細野裕樹, 戸谷真理子, 森本克也, 鈴木博章

Microanalysisy System Based on Electrochemiluminescence with Automatic Mixing and pH-regulation Functions

Wataru SATOH, Hiroki HOSONO, Mariko TOYA, Katsuya MORIMOTO, Hiroaki SUZUKI

Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573

In conducting a bio/chemical analysis on a chip, several different procedures are usually required. These include the transport of necessary solutions, timely mixing of necessary solutions, pH-regulation, and detection. In this study, we demonstrate the possibility to conduct all necessary procedures on a single chip. Our fabricated device has functions such as (1) automatic mixing of solutions, (2) pH-regulation, and (3) detection based on electrochemiluminescence (ECL).
The automatic mixing was achieved by using electrowetting. A reagent solution containing Ru(bpy)32⁺ and a sample solution containing an amino acid were mixed and the pH was adjusted using the above-mentioned mechanisms. When +1.1 V (vs. Ag/AgCl) was applied to the electrode, red luminescence was observed. The ECL intensity increased with the increase in the concentration.

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22.

イオン注入によるePTFE改質膜を用いた電気化学式ガスセンサの出力特性

^*理研計器（株），^**理化学研究所

○岡村圭^*，打越祥一^*，中野信夫^*，石地徹^*，戸井田浩^**，鈴木嘉昭**，高橋勝緒**

Electrochemical Gas Sensor Using ePTFE Membrane Modified by Ion Implantation

Kei OKAMURA^*, Shoichi UCHIKOSHI^*, Nobuo NAKANO^*, Toru ISHIJI^*, Hiroshi
TOIDA^**, Yoshiaki SUZUKI^**, Katsuo TAKAHASHI^**

^*Riken Keiki Co., Ltd.
Itabashi-ku, Tokyo 174-8744, Japan
^**RIKEN (The Institute of Physical and Chemical Research)
Wako-shi, Saitama 351-0198, Japan

Electrochemical gas sensors have been widely used for industrial purposes and environmental monitoring. We tried to use ion implantation into expanded polytetrafluoroethylene (ePTFE) membranes for the surface modification. These membranes with Au ion-plating were used as the gas permeable electrodes of the electrochemical gas sensors. The sensors showed a good sensitivity and selectivity for H₂ detection. Especially the sensors used N⁺_-, N₂⁺_-, O⁺_-, and O₂⁺_-implanted ePTFE membrane with fluences of above 1 X 10¹⁵ ions/cm² showed significant effect. The sensors used H⁺_-, He⁺_-, Ne⁺_-, and Kr⁺_-implanted were not so effective to the enhancement. Morphology change of ePTFE by ion implantation was examined by SEM and FT-IR-ATR spectroscopy.

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電気泳動法によるペロブスカイト型酸化物厚膜電極の作製とイオン検知特性

九工大工

○高瀬聡子、稲垣　徹、清水陽一

Preparation and Ion Sensing Prorepties of Perovskite-Type Oxide Thick Film by EPD
Process

Satoko TAKASE, Toru INAGAKI and Youichi SHIMIZU
Department of Applied Chemistry, Faculty of Engineering,
Kyushu Institute of Technology,
1-1 Sensui-cho, Tobata, City of Kitakyushu 804-8550

A LaCoO₃ thick-film could be prepared on the electrode materials from ethanol-based suspension with acetylacetone or polyvinylalcohol as a stabilizer by electrophoretic deposition (EPD) process. Acetylacetone was found be an efficient stabilizer for LaCoO₃ fine powder suspension for EPD. The LaCoO₃ fine powder could be synthesized at 380℃from polymer precursors prepared with ethylenediamine (EDA) as chelating agent and polyethylene glycol (PEG) as a polymer additive. The LaCoO₃ thick-film devise showed good amperometric responses to HPO₄^2- with high stability and high selectivity.

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インターカレーション物質を用いたイオン選択性電極の全固体化

東京理科大理

○長谷川　卓,　 齊藤　治之,　駒場　慎一

All-Solid-State Ion-Selective Electrode Based Upon Electroactive Insertion Material

Taku HASEGAWA , Haruyuki SAITOH, and Shinichi KOMABA

Tokyo University of Science

All-solid-state ion-selective electrode was constructed using insertion materials such as LiFePO₄ or Na_0.44MnO₂ composite covered with a plasticized poly(vinyl chloride) (PVC) membrane containing the ionophore. LiFePO₄ and Na_0.44MnO₂ were prepared by hydrothermal synthesis and solid state reaction, respectively. The upper PVC layer is formed by casting on the insertion electrode. The lithium ion selective electrode exhibited near-Nernstian response to lithium ion in the concentration range between 6×10^-5〜10^-1 mol dm^-3 and not to other alkaline metal ions. Selective coefficient for lithium ion against sodium and potassium ions was found to be: logK^Pot_LiNa=-4.17 and logK^Pot_Lik=-4.16

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ナノホールアレーにもとづくフロースルー型電極の作製と微量測定への応用

首都大都市環境^a, 神奈川科学技術アカデミー^b, 日本学術振興会^c

○原田真宏^a,c, 西尾和之^a,b, 益田秀樹^a,b

Fabrication of Flow-Through Type Electrode Using Anodic Porous Alumina and Its
Application to Microelectrochemical Detection

M. Harada^a,c , K. Nishio^a,b , and H. Masuda^a,b

^a Department of Applied Chemistry, Tokyo Metropolitan University,
1-1 Minamiosawa, Hachioji, Tokyo 192-0397, Japan
^b Kanagawa Academy of Science and Technology,
5-4-30, Nishi Hashimoto, Sagamihara, Kanagawa, 229-1131, Japan
^cResearch Fellowships of the Japan Society for the Promotion of Science for Young Sientists,
8 Ichibanchyou, Chiyoda, Tokyo 102-8472, Japan

Flow-through type Au nanohole array electrodes with a hole period of 500 nm were fabricated using an ideally ordered anodic porous alumina as a template, and were used to the detection of Pb²⁺ in the solution. The obtained Au hole arrays had geometrical structures identical with those of the starting template. In the measurement of the anodic stripping peak current of Pb^2＋, the Au nanohole array electrodes showed good linearity in the concentration range from 500 pM to 3 nM. The present technique can be used for various metal ions in environment.

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電子ビーム蒸着法を用いた光ファイバ水素センサデバイスの開発

横浜国立大学^a　東京大学先端科学技術センター^b

○稲葉隆之^a　渡辺太一^a 　松山直人^a　伊藤大輔^a　横山隆^a　岡崎慎司^a　中川英元^b

Development of a Fiber-Optic Hydrogen Sensor Using Electron Beam Deposition Method

Takayuki INABA^a, Taichi WATANABE^a, 　Naoto MATUYAMA^a, Daisuke ITO^a 　Takasi
YOKOYAMA^a,　Shinji OKAZAKI^a and　Hidemoto NAKAGAWA<sup>b

a</sup>Yokohama National University,
Kanagawa-ken, Yokohama-shi, Hodogaya-ku ,Tokiwadai79-5
^bResearch Center For Advanced Science And Technology, Tokyo University,
Toukyo-to, Meguro-ku, Komaba4-6-1

An optical fiber hydrogen sensor which consists of a Pt/WO₃-coated fiber was fabricated by electron beam deposition method. The working mechanism of this sensor is based on the absorption changes of the evanescent waves. In the presence of hydrogen gas, WO₃ was reduced to HxWO₃. The optical property of the sensing clad was considerably changed by this reaction. When the sensor was exposed to 10vol.%H₂/N₂, normalized optical power propagating through the optical fiber decreased to 85% within two minutes. The sensor performance depended on the thickness of WO₃ and Pt . The sensitivity increased with the increment of WO₃ thickness. Furthermore, the deposition rate of WO₃ film also influenced the sensing characteristic. The sensor using WO₃ film deposited at high speed showed good sensitivity.

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放射性廃棄物処分容器の長期腐食モニタリング用光ファイバ酸素センサの開発

横浜国大工^a、東京大学先端科学技術研究センター^b、電源開発株式会社^c

○中村 祐樹^a、伊藤 大輔^a、横山隆^a、岡崎 慎司^a、中川 英元^b、新井 隆^c

Development of a Fiber-Optic Oxygen Sensor for Long-Term Corrosion Monitoring of
Radioactive-Waste Disposal Tanks

Yuki NAKAMURA^a, Daisuke ITO^a,Takashi YOKOYAMA^a, Shinji OKAZAKI^a ,Hidemoto
NAKAGAWAb and Takashi ARAIc

^aFaculty of Engineering, Yokohama National University,Tokiwadai 79-5,
Hodogaya-ku, Yokohama 240-8501, Japan,
^bResearch Center for Advanced Science
and Technology, Tokyo University, Komaba 4-6-1, Meguro-ku, Tokyo
153-8904,Japan,
^cElectric Power Development Co.,Ltd. Ginza 6-15-1, Chuo-ku,
Tokyo 104-8165, Japan

A fiber-optic oxygen sensor for long-term use was developed and its durability was evaluated. The sensing mechanism is based on quenching of luminescence by oxygen. Ruthenium complex whose counter-anion is dodecyl sulfate was utilized as fluorescence dye. This complex was dispersed into silicone rubber. This sensing material was immobilized on quartz substrate by curing at ambient temperature. In order to clarify the long-term stability of the sensor, degradation tests were conducted at different temperature conditions. The complicated degradation behaviors were observed. At the initial stage of the test, the sensitivity rapidly decreased and reached steady state. However, it gradually degraded after the plateau for several days. The half decay period with respect to the sensitivity strongly depended on the test temperature. From the simple life-time estimation, It is clarified that sensing membrane would have good performance and long-term stability in practical environment. Therefore, the sensor would be suitable for long-term corrosion monitoring of radioactive-waste disposal tanks.

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色変化で視認できる蛍光酸素センサチップの開発

産総研^a，（株）東亜電化^b

○加藤　隆二^a，中村　正幸(^b)，佐々木　八重子^b，古部　昭広^a，横山　敏郎^a，南條　弘^a

Development of Oxygen Sensor Based on Fluorescence Color Change

Ryuzi KATOH^a, Masayuki NAKAMURA^b, Yaeko SASAKI^b, Akihiro FURUBE^a,
Toshiro YOKOYAMA^a, Hiroshi NANJO^a

National Institute of Advanced Industrial Science and Technology (AIST),AIST Tsukuba Central 5, Tsukuba, Ibaraki 305-8565.
^bTOADENKA, Co.Ltd, Tamayama, Morioka, Iwate 028-4132

It is known that the fluorescence of organic molecules is efficiently quenched by oxygen. Using this photochemical process, several types of oxygen sensors have been proposed so far. For the many fluorescence oxygen sensors proposed, fluorescence intensity has to be measured precisely with a photo-detector, such as photomultiplier. Thus, practical application of such sensors is limited by the photo-detection systems. We propose here a new type of oxygen sensor based on visual observation of fluorescence color. In the sensor, no large equipment is needed to detect oxygen, except for a small LED as an excitation source.

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Ptショットキーゲート電界効果型GaNガスセンサ

石巻専修大理工

樋口忠宗，○中込真二，國分義弘

Field Effect GaN Gas Sensors with a Pt Schottky Gate

Tadamune HIGUCHI, Shinji NAKAGOMI, Yoshihiro KOKUBUN

Faculty of Science and Engineering, Ishinomaki Senshu University,
Ishinomaki-shi, Miyagi 986-8580, Japan

Gas sensor devices with three terminal planer structure based on GaN have been fabricated. The device consists of two Ohmic and one Pt Schottky gate electrode. The current-voltage characteristics for the source to drain region were measured in H₂ and O₂ atmospheres at high temperatures up to 300℃.
The drain current increased due to the change of atmosphere from O₂ to H₂. The voltage response for a constant current increased with increasing hydrogen concentration of the atmosphere over a wide range (3-10000 ppm). It also increased with increasing gate voltage. The larger voltage response was observed as compared with conventional Schottky diode gas sensors.

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ダイオード型センサの水素検知特性 − Pd電極組成の検討 −

長崎大 ¹工，²院生産科学

兵頭健生¹，坂本恵子²，清水康博¹，江頭　誠¹

Hydrogen Sensing Properties of Diode-Type Gas Sensors -Effects of Palladium Electrode Composition-

Takeo HYODO¹, Keiko SAKAMOTO², Yasuhiro SHIMIZU¹ and Makoto EGASHIRA<sup>1

1</sup>Faculty of Engineering, ²Graduate School of Science and Technology,
Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521

Hydrogen sensing properties of diode-type TiO₂ sensors coupled with Pd-nM electrodes (Pd-nM/TiO₂, M = Ag or Pt, n: composition of M in the alloy electrode (0〜100 wt%)) have been investigated under various conditions. H₂ response of Pd/TiO₂ sensor was higher than those of Pt/ TiO₂ and Pd-nAg/TiO₂ sensors, while Pt/TiO₂ showed quite excellent recovery properties among them. The use of Pd-nPt (n = 64〜72) alloy electrodes was effective for achieving the large H₂ response in dry air. In addition, the recovery speed of Pd-64Pt/TiO₂ sensor in dry N₂ was largely improved, while the response speed was comparable with that of Pd/TiO₂ sensor in dry N₂.

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FET型NOxセンサの検知電極の検討

九大院総理工

〇井上浩文^a、湯浅雅賀^b、木田徹也^b、島ノ江憲剛^b、山添　�f^b

Investigation of Sensing Electrode Materials for FET-type NOx Sensor

Hirofumi INOUE^a, Masayoshi YUASA^b, Tetsuya KIDA^b, Kengo SHIMANOE^b, Noboru YAMAZOE^b

^aInterdisciplinary Graduate School of Engineering Sciences, Kyushu University,
^bFaculty of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580

New sensing materials were investigated for a FET-type NOx sensor attached with a NaNO₂-based auxiliary phase in order to improve the sensitivity and the selectivity of the sensor to NO₂. In this study, Ru-loaded WO₃ was selected as a sensing material because of its good adsorptive properties for NO₂. Ru-loaded WO₃ was mixed with NaNO₂ and the mixture was attached onto a FET device as the sensing auxiliary phase. The FET-device with Ru/WO₃-NaNO₂ showed good selectivity toward NO₂ and high response- and recovery-speeds in response to NO₂ in ppb concentrations at 130 and 170℃.

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酸化スズ系ガスセンサにおける選択性の長期安定性に関する検討

新コスモス電機

○前川　亨、皆越知世、中村俊一

Long-Term Stability of the GAS Slectivity in SnO₂ Gas Sensor

Toru MAEKAWA, Chise MINAGOSHI, Shun-ichi NAKAMURA

New Cosmos Electric Co., Ltd.

Sensors with different catalytic layer of SnO₂, Ce-SnO₂ and Al-Ce-SnO₂ were prepared for the investigating of long-term stability of the gas selectivity.
The catalyst of Al-Ce-SnO₂ was prepared by co-doping Ce and Al into SnO₂. The dopants Ce and Al were used for suppressing grain growth at high temperature and making a catalytic layer of high resistance to avoid the sensitivity of the sensor being affected by changes in resistance of the layer, respectively. The sensors with the catalytic layer of Ce-SnO and Al-Ce-SnO₂ performed with good long-term stability of gas selectivity in the experiment.

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金ナノ粒子修飾くし型電極を用いたＶＯＣセンサの応答原理の検討

熊本大院

○山名　来充恵，松村　明子，冨永　昌人，谷口　功

Study on the Response Mechanism for VOC Sensor Using Interdigitated Microelectrode (IME) Modified with Au Nanoparticles

Kumie Yamana, Akiko Matsumura, Masato Tominaga, Isao Taniguchi

Graduate School of Science and Technology, Kumamoto University
Kurokami, Kumamoto 860-8555, Japan

Gold nanoparticles film can be prepared by crosslinking nanoparticle cores with organic molecules such as bifunctional alkanedithiols. These linker molecules act as insulating barriers between the metal cores, and determine the distances between the metal cores. In this study, we prepared interdigitated microelectrode (IME) covered with Au nanoparticles film by crosslink process using 11-mercaptoundecanoic acid (MUA) as a linker molecule. Impedance response for Au nanoparticles film modified IME (MUA-Au/IME) was investigated, when MUA-Au/IME was exposed to ethanol, 2-propanol, hexane and toluene vapors. Impedance response strongly depended on volatile organic compounds　(VOC), especially hydrophile VOC such as ethanol and 2-propanol. The impedance response mechanism was discussed in this study. High impedance responses for hydrophile VOC depended on hydrogen bond for MUA, which could be understood by equivalent circuit parameters on Cole - Cole plots.

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複素インピーダンス法による酸化スズマイクロガスセンサの粒界および界面抵抗の評価

立命館大理工

○大谷哲史、玉置　純

Evaluation of Resistances at Grain Boundary and Grain-Electrode Interface in Tin Oxide
Thin Film Microsensors

Tetsuji Otani, Jun Tamaki

Department of Applied Chemistry, Faculty of Science and Engineering, Ritsumeikan University,
Kusatsu-shi, Shiga 525-8577, Japan

In dilute xylene sensing using SnO₂ thin film microsensors, resistances at grain boundary and grain-electrode interface have been individually and directly evaluated by using complex impedance easurements. Micro-gap electrodes with various gap-sizes of 0.12-0.95 μm were fabricated on SiO₂ substrate by means of MEMS techniques (photolithography and FIB). Then SnO₂ sol was dropped on the micro-gap electrode, dried and calcined at 500℃ for 3 h to be SnO₂ thin film microsensor. The complex impedance easurements were carried out in air and 0.01-1 ppm xylene at 450℃. Single semicircle in Nyquist plot was obtained for the SnO₂ microsensor with large gap size because of overlapping of contribution of grain boundary and grain-electrode interface. The part at high frequency side was gradually decreased with decreaseing gap size. And the Nyquist plot was divided into two semicircles for the SnO₂ microsensor with 0.12 and 0.23 μm gap. From this behavior, it is assumed that semicircle at high frequency side is contributed to grain boundary and that at low frequency side is to grain-electrode interface. The Nyquist plots were fit to equivalent circuit in air and xylene, the resistances at grain boundary and grain-electrode interface were evaluated as a function of xylene concentration. As a result, it was found that sensitivities of grain-electrode interface (Si) were much higher than that of grain boundary (Sgb) in each xylene concentration.

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酸化スズ薄膜マイクロセンサの可燃性ガス検知特性に及ぼすマイクロギャップの効果

立命館大理工

○中田谷昌徳、小西　聡、玉置　純

Effect of Micro-Gap Electrode on Inflammable Gas Sensing Properties of Tin Oxide Thin
Film Microsensors

Yoshinori Nakataya, Satoshi Konishi^*, Jun Tamaki

Department of Applied Chemistry, Faculty of Science and Engineering, Ritsumeikan University,
Kusatsu-shi, Shiga 525-8577, Japan

^*Department of Micro System Technology, Faculty of Science and Engineering,
Ritsumeikan University, Kusatsu-shi, Shiga 525-8577, Japan

The effects of microgap size and electrode material have been investigated on inflammable gas sensing properties (H₂S, CO, C₃H₈) of SnO₂ thin film microsensors equipped with Au or Pt electrode. The microgap electrode was fabricated by means of MEMS techniques (photolithography and FIB) and the gap size was varied in the range of 0.1-1 μm. The sensor responses (S) to all inflammable gases were slightly increased with decreasing gap size for SnO₂ microsensors with Au electrode. However, the microgap effect largely appeared for SnO₂ microsensor with Pt electrode. It is considered that this enhancement of microgap effect results from the change in interface properties at oxide-electrode interface. Indeed, the sensor response at interface (Si) was increased in H₂S sensing for SnO₂ microsensor with Pt electrode, while the sensor response at grain boundary (Sgb) almost remained unchanged. Further, Si for SnO₂ microsensor with Pt electrode was steeply decreased with decreasing H₂S concentration. This reveals the properties of SnO₂-Pt interface.

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ナノギャップ櫛型電極を用いた高感度二酸化窒素センサの構築

立命館大理工

○鵜野雄大、橋新　剛、ダオ　ズンべト、杉山　進、玉置　純

High Sensitivity NO₂ Gas Sensor Equipped with Nano Interdigitated Electrode

Yudai Uno, Takeshi Hashishin, Dzung V. Dao^*, Susumu Sugiyama^*, Jun Tamaki

Department of Applied Chemistry, Faculty of Science and Engineering, Ritsumeikan University,
Kusatsu-shi, Shiga 525-8577, Japan
^*Department of Micro System Technology, Faculty of Science and Engineering, Ritsumeikan University,
Kusatsu-shi, Shiga 525-8577, Japan

The high sensitivity gas sensor to dilute NO₂ was attained in WO₃ thin film nano sensor equipped with nano interdigitated Au electrode (distance between tooth : 200〜300 nm, number of tooth : 10〜50). The sensitivity to dilute NO₂ less than 0.1 ppm was increased with increasing number of tooth in interdigitated electrode. The WO₃ nano sensor with interdigitated electrode of 200 nm distance and 50 teeth showed the extremely high sensitivity (Ra/Rg = 28) to 0.01 ppm NO₂ at 200 ℃ as well as the excellent response-recovery characteristics. This behavior was interpreted with the length of oxide-electrode interface, i.e., the sensitivity was increased with increasing length of interface, because the sensitivity at interface was higher than that at grain boundary due to the micro-gap effect found in NO₂ sensing-WO₃ sensor system. It was demonstrated that the nano-design of electrode structure was important for the development of high sensitivity gas sensor.

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酸化タングステンスパッタ膜を用いたNO₂ガスセンサの膜厚依存性

富山大工

○劉志甫，山崎登志成，沈岩柏，喜久田寿郎，中谷訓幸

Influence of Film Thickness on Gas Sensing Properties of Sputtered WO₃ Thin Film Gas Sensors

Zhifu LIU, Toshinai YAMAZAKI, Yanbai SHEN, Toshio KIKUTA, Noriyuki NAKATANI
Faculty of Engineering, University of Toyama, Toyama 930-8555, Japan

The effects of film thickness on the gas sensing properties of WO₃ films have been investigated by measurements of XRD, AFM, and gas sensing to NO₂.
The porous and dense WO₃ films were deposited by DC reactive sputtering at different discharge pressures. The films became discontinuous when the thickness decreased to 15 nm. The gas sensitivity increased with the reduction of film thickness. But the sputtered films were hardly sensitive to NO₂ when the film was thinner than 15 nm because of the discontinuity. The microstructure parameters such as porosity were less important to gas sensing for the films with a thickness comparable to depletion layer.

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超音波噴霧熱分解法による多孔質セラミックス粉末の調製 と半導体ガスセンサへの応用

長崎大工

橋本麻由，兵頭健生，清水康博，江頭　誠

Preparation of Porous Ceramic Powders by Pyrolysis of Atomized Precursor Solutions
and Their Application to Semiconductor Gas Sensors

Mayu HASHIMOTO, Takeo HYODO, Yasuhiro SHIMIZU and Makoto EGASHIRA

Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University,
1-14 Bunkyo-machi, Nagasaki 852-8521

Porous SnO₂ (pr-SnO₂) powders were prepared by pyrolysis of atomized SnCl₄ aqueous solutions containing polymethylmethacrylate (PMMA) microspheres (150 nm in diameter) as a template. Spherical macropores reflecting the morphology of PMMA template (100-150 nm in diameter)
could be formed in the pr-SnO₂ powders (0.5-1 μm in diameter). H₂ response of the pr-SnO₂ was low, while addition of noble metal (especially, Pt) was effective for improving the H₂ response of the pr-SnO₂. In addition, a pr-SnO₂ added with both noble metal and Sb₂O₅ showed the largest H₂ response along with relatively low resistance in air.

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産総研

○伊豆典哉、伊藤敏雄、申ウソク、松原一郎

CO Gas Response of Gas Sensor Using Zr-Doped Ceria Thick Film

Noriya IZU, Toshio ITOH, Woosuck SHIN, Ichiro MATSUBARA

National Institute of Advanced Industrial Science and Technology (AIST),
2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya, Aichi 463-8569

We made a new sensor having porous zirconium-doped cerium oxide thick films and a Pt/Al₂O₃ catalyst layer, and investigate response properties to CO, H₂, and O₂. The resistance of the films and the output signal of the sensor changes when the atmosphere changes from air to air with 330 ppm CO or more. The 90% response time of thick film without a catalyst layer to CO is determined to be about 10 s. The proposed sensor has a potential to respond very quickly. The sensor shows no response to a change in oxygen concentration.

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マクロポーラス半導体センサの作製とそのニオイ成分検知特性

長崎大 ¹院生産科学，²工

野中脩平¹、兵頭健生²、清水康博²、江頭　誠²

Preparation of Macroporous Semiconductor Gas Sensors and Their Odour Sensing
Properties

Shuhei NONAKA¹, Takeo HYODO², Yasuhiro SHIMIZU² and Makoto EGASHIRA<sup>2

1</sup>Graduate School of Science and Technology, ²Faculty of Engineering,
Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521

Macroporous (mp-) oxide films (SnO₂ and WO₃) were fabricated by a modified sol-gel technique employing polymethylmethacrylate (PMMA) microspheres as a template. NH₃ responses of all the mp-oxide films prepared were much lower than those of reference (R-) oxide films fabricated by screen printing of the sol-gel driven powder, probably because of less reactivity of NH₃ originating from their macroporous structure. On the other hand, their mp-oxide films (especially, mp-SnO₂ added with CuO at 200℃) showed much large H₂S response in comparison to those of R-oxide films. Especially, the addition of CuO was quite
effective for improving the H₂S response and the recovery speed of mp- SnO₂ film.

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ボールSAW素子の原理と応用

^a東北大学、^b科学技術振興機構、^c凸版印刷、^d株式会社 山武、^eBall Semiconductor inc.

山中一司^a,b、中曽教尊^c、吹浦　健^d、沈東演^e

Development of Ball SAW Sensor

Kazushi YAMANAKA^a,b, Noritaka NAKASO^c, Takeshi FUKIURA^d,Dong Youn SIM^e

A thin beam of wave usually diverges due to diffraction, which is a limitation of any device using such waves. However, a surface acoustic wave (SAW) on a sphere with an appropriate aperture does not diverge but is collimated, realizing ultramultiple roundtrips along an equator of the sphere. This effect is caused by the balance between diffraction and focusing on a spherical surface, and it enables realization of high-performance ball SAW sensors.

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抵抗型酸素センサの応答機構解明とその実用化に関する研究

産総研

○伊豆典哉

Study on Response Mechanism of Resistive Type Oxygen Sensor and Its Development for Practical Use

Noriya IZU

National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya, Aichi 463-8569

Recently resistive oxygen sensors have again become the focus of much attention because they have simpler structure and it is easy to downsize them. Here I report the trend of research and development of the resistive oxygen sensors using cerium oxide (ceria), which have a good corrosion resistance to corrosive gases. First, I describe the study on response mechanism of resistive type oxygen sensor. Second, I describe the study on the improvement of response speed of the sensor. Third, I describe the study on the improvement of other sensing properties such as decrease of temperature dependence of output of the sensor.

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BiCuVOx固体電解質を用いたVOCsセンサの検討

九大院総理工

○南　卓也・湯浅雅賀・木田徹也・島ノ江憲剛・山添　�f

VOCs Gas Sensor Using BiCuVOx Solid Electrolyte

Takuya MINAMI, Masayoshi YUASA, Tetsuya KIDA, Kengo SHIMANOE,Noboru YAMAZOE

Department of Molecular and Material Sciences,Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580

A new-type VOCs sensor using BiCuVOx (Bi₂Cu_0.1V_0.9O_5.35) and a La-Co based perovskite-type oxide as a solid electrolyte and an electrode, respectively, has been developed. Electromotive force (EMF) of the sensor attached with the BiCuVOx-La_0.6Sr_0.4Co_0.8Fe_0.2O₃ composite electrode was measured in various VOCs gases (propane, toluene, formaldehyde) at various temperatures between 350 and 500℃. The sensor responded to 10 ppm formaldehyde and toluene, but showed negligible sensitivity to propane, and the EMF of the sensor was linear to the logarithm of the formaldehyde and toluene concentrations at 350℃ and 400℃. The high sensitivity of the sensor observed at low temperatures is probably owing to the good oxide-ionic conductivity of BiCuVOx and high oxidative activity of the perovskite-type oxide at low temperatures.

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YSZを用いたVOC電位応答型ガスセンサ

愛媛大院

森雅美、八尋秀典、○定岡芳彦

Potentiometrical Detection of VOCs with M(I)/8YSZ/M(II) Device

Masami MORI, Hidenori YAHIRO and Yoshihiko SADAOKA,
Graduate School of Science and Engineering, Ehime University,
3 Bunkyo-cho, Matsuyama 790-8577

A galvanic cell with P"(O₂), M(anode)/8YSZ/M(cathode), P'(O₂) structure is useful to detect O₂ concentration in ambient. We investigated the interface between the electrodes and the 8YSZ sheet for this potentiometric device. The sensing behaviour was influenced by the surface of the YSZ sheet and the used electrode materials at lower temperatures, 350-450℃. In the separate type device, the use of the Au electrode instead of Pt electrode resulted a higher output potential. The device with Pt/YSZ/Au structure where the both electrodes were in the same ambient gava a high sensitivity to oxygen and acetic acid.

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固体電解質CO₂ガスセンサにおける固体参照極/NASICON固体電解質界面の構造解析

九大院総理工

○岸章太郎、湯浅雅賀、木田哲也、島ノ江憲剛、山添�f

Interfacial Structure between Solid Reference Electrode and NASICON before and after
Heat Cycle Test in a Saturated Humidity for a NASICON-Based CO₂ Gs Sensor

Shotaro KISHI^a, Masayoshi YUASA^b, Tetsuya KIDA, Kengo SHIMANOE^b, Noboru YAMAZOE^b
aInterdisciplinary Graduate School of Engineering Sciences, Kyushu University,
^bFaculty of Engineering Sciences, Kyushu University,
Kasuga-shi,Fukuoka 816-8580

A composite of a perovskite type oxide (La_0.6Sr_0.4Co_0.78Ni_0.02Fe_0.2O₃) and BiCuVOx(Bi₂Cu_0.1V_0.9O_5.35) was investigated as a reference electrode for a potentiometric CO₂ sensor using NASICON (Na⁺ conductor, Na₃Zr₂Si₂PO₁₂). It was found that the potentioal of the composite electrode was very stable to exposure of CO₂ gas at 400℃ under humid conditions. In order to examine the start-up characteristics of the CO₂ sensor, the sensor was exposed to high humid conditions(100%RH) saturated at 38℃ for 1-2 days and then re-heated at the operating temperature of 100℃(heat-cycle test). The sensor showed good CO₂ sensing properties and the potential of the composite electrode was stable even after the heat-cycle test. SEM-EDX measurements revealed that a reaction layer was formed at the interface between NASICON and the conposite electrode, and that the thickness of the reaction layer slightly increased after the heat-cycle test.

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固体電解質型CO₂ガスセンサの補助相への応用を目的としたLi₂CO₃-Nd₂O₃系熱処理生成物の検討

愛媛大院　

○青野 宏通、板垣 吉晃、定岡 芳彦

Characterization of Heated Mixture of Li₂CO₃-Nd₂O₃System for Application of Auxiliary
Phase on CO₂ Gas Sensor

Hiromichi AONO, Yoshiteru ITAGAKI, and Yoshihiko SADAOKA

Department of Materials Science and Biotechnology, Graduate School of
Science and Engineering, Ehime University, Bunkyo-cho 3, Matsuyama,
Ehime 790-8577

Gradual changes (drift) in the EMF level with time were observed for the CO₂ gas sensor using NASICON solid electrolyte and only Li₂CO₃ as the auxiliary electrode. A new auxiliary electrode material of Li₂CO₃ and Nd₂O_2+2x(CO₃)_1-xLi₂x mixed phase was obtained by the heating in CO₂ gas atmosphere. The EMF value was stabilized by the utilization of this auxiliary material. For the mixture of Na₂CO₃ and Nd₂O₃, the heat treatment in CO₂ gas induced the formation of only Nd₂O₂CO₃. A higher reactivity of the Li-ion with Nd₂O₂CO₃ and a lower reactivity of the Na-ion effectively stabilized the diffusion boundary layer.

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選択的NO₂ 検知が可能なAu薄膜検知極を用いたプレナー型ジルコニアセンサ

九大産学連携センター^a, 九大院総理工^b

○ V. V. Plashnitsaa, 上田　太郎^b, P. Elumalaia, 三浦　則雄^a

Selective YSZ-Based Planar NO₂ Sensor Using Nano-gold Sensing Electrode

○ Vladimir V. PLASHNITSA^a, Taro UEDA^b, Perumal ELUMALAI^a, Norio MIURA^a
a Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^b Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580

The sensing performances of planar yttria-stabilized zirconia (YSZ)-based NOx sensor using the nanostructured Au thin-films having the thicknesses of 60 nm-1.2 μm as a sensing electrode (SE) were evaluated at 600℃ under dry and wet (5 vol.% H₂O)　conditions when the sensor was exposed to the sample gas containing each of CO, CH₄, C₃H₈, NO (400 ppm each) and NO₂ (50-400 ppm). As a result, the sensor using the 350 nm-thick Au-SE was found to give the highest NO₂ sensitivity which seemed to be attributed to the higher catalytic activity for the cathodic reaction of NO₂ as well as the lower catalytic activity to anodic reaction of oxygen at the interface of Au/YSZ. In addition, this sensor　was found to give an excellent selectivity to NO₂.

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YSZロッドとMn系新規固体参照極を用いた小型プレナー酸素センサ

九大院総理工^a、九大産学連携センター^b

○和間 良太郎^a、中久保 昌平^a、三浦 則雄^b

Compact Planar-Type Oxygen Sensor Using YSZ-Rod and New Mn-Based Solid
Reference-Electrode

○Ryotaro WAMA^a , Shohei NAKAKUBO^a, Norio MIURA^b

^a Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580
^b Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka 816-8580

The compact planar-type oxygen sensor was fabricated by using a YSZ-rod (length: 10 mm, diameter: 3 mm) as a main construction material, Mn₂O₃ as a reference-electrode material and Pt as a sensing-electrode material, and its sensing characteristics were evaluated. As a result, it was confirmed that the present sensor could be used for the oxygen deficiency detection at 600℃ in the presence of 400 ppm CO₂ and 1 vol.% H₂O. This sensor was hardly affected by the presence of other gases such as CO, CH₄, C₃H₈, H₂, NO and NO₂. In addition, the drift of the emf value of the sensor in air was found to be less than ± 0.5 mV after keeping it in an atmospheric air at 600℃ for about 6 months, indicating a good long-term stability of the sensor. Furthermore, the compact sensor could also operate well as a lambda sensor for combustion of propane.

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In³⁺ドープSnP₂O₇を電解質に用いた室温作動型水素センサ

名大院環境^a、産総研^b

○行方 陽介^a、長尾 征洋^a、冨田 衷子^b、日比野 高士^a

Room-Temperature Hydrogen Sensors Based on an In³⁺-doped SnP₂O₇ Proton Conductor

Yosuke NAMEKATA^a, Masahiro NAGAO^a, Atsuko TOMITA^b, Takashi HIBINO^a

^a Department of Environmental Engineering and Architecture, Graduate School of Environmental Studies,
Nagoya University,Chikusa-ku, Nagoya 464-8601
^b National Institute of Advanced Industrial Science and Technology (AIST),Moriyama-ku, Nagoya 463-8560

A potentiometric solid-state gas sensor was fabricated using a proton-conducting Sn_0.9In_0.1P₂O₇ electrolyte with an active Pt/C working electrode in order to study its　sensing properties for small quantities (100 ppm-3%) of H₂ in air at room temperature. The sensor showed electromotive force (EMF) response in the negative direction to　changes in the H₂ concentration. Furthermore, the EMF value varied linearly with the logarithm of the H₂ concentration, while it was minimally affected by the water-vapor concentration. The sensing mechanism was shown to be based on the mixed potential　at the working electrode through measurements of the polarization curves of H₂ and air. The Sn_0.9In_0.1P₂O₇ electrolyte was also applied in two single-chamber H₂ sensors, wherein Pt/C and carbon were used as active and inactive electrodes, respectively; these electrodes were attached on the opposite surfaces or on the same surface of the electrolyte. Both single-chamber sensors could exhibit comparable H₂ sensitivities, compared to the dual-chamber sensor.

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プロトン伝導体を用いた水素センサの開発

新コスモス電機^a、産総研^b

○皆越知世^a、今林秀和^a、中村俊一^a、前川亨^a、鈴木健吾^a、野村勝裕^b、蔭山博之^b

Development of the Hydrogen Gas Sensor Using a Proton Conductor

Chise MINAGOSHI,^a Hidakazu IMABAYASHI,^a Shun-ichi NAKAMURA,^a　
Toru MAEKAWA,^a Kengo SUZUKI,^a Katsuhiro NOMURA,^b Hiroyuki KAGEYAMA^b

^a New Cosmos Electric Co., Ltd.
2-5-4 Mitsuya-naka, Yodogawa-ku, Osaka 532-0036
^b National Institute of Advanced Industrial Science and Technology(AIST)
1-8-31 Midorigaoka, Ikeda, Osaka 563-8577

A solid electrolyte type hydrogen gas sensor has been developed using Sr-doped LaScO₃ (La_0.9Sr_0.1ScO_2.95). The La_0.9Sr_0.1ScO_2.95 sensing element was fabricated on an alumina substrate with a Pt thin film heater on the back side, where a pair of Pt electrodes was fixed to the sensing element and one of the electrodes was enclosed with glass to prevent reaction of H₂ at the electrode. The sensor showed high sensitivity and selectivity to H₂ in a concentration range of 100 to 50000ppm at 500℃, with fast response and good long-term stability.

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LPD法により成膜したYSZ薄膜を用いた固体電解質型水素センサの開発

新コスモス電機^a、神戸大工^b

○中里嘉浩^a、嶋嵜僚太郎^a、伊藤達也^a、鈴木健吾^a、坂本宗明^b、水畑　穣^b、出来成人^b

A Solid Electrolyte Type Hydrogen Gas Sensor Using Yttria Stabilized Zirconia by the
Liquid Phase Deposition Method

Yoshihiro NAKAZATO^a, Ryotaro SHIMAZAKi^a, Tatsuya ITO, Kengo SUZUKI^a,
Muneaki SAKAMOTOb, Minoru MIZUHATA^a, and Shigehito DEKI^b

^aNew Cosmos Electric Co., Ltd.
2-5-4 Mituya-naka, Yodogawa-ku, Osaka 532-0036, Japan

^bDepartment of chemical Science and Engineering, Faculty of Engineering, Kobe University.
1-1 Rokkodai, Nada, Kobe 657-8501, Japan

A solid electrolyte type hydrogen (H₂) gas sensor has been developed using yttria stabilized zirconia (YSZ) sensing film. The YSZ sensing film was deposited on an alumina substrate with a Pt thin film heater on the other side by the liquid phase deposition (LPD) method. The sensing characteristic of the sensor was investigated by measuring H₂ and some of interference gases in a concentration range of 100-10000ppm. The sensor showed high sensitivity to H₂ and very low sensitivity to the interference gases with fast response.

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