Vol. 11, Supplement B (1995)

Vol. 11, Supplement B (1995)

Proceedings of the 21st Chemical Sensor Symposium
September 29-30, 1995
Yamanashi University

Abstracts

1.
ポリイオンコンプレックス担体を用いた酵素センサによる
乳酸、グルコースのフローインジェクション分析

水谷文雄、矢吹聡一、平田芳樹

生命工研

FLOW-INJECTION ANALYSIS FOR L-LACTIC ACID OR GLUCOSE USING AN AMPEROMETRIC ENZYME ELECTRODE BASED ON POLYION COMPLEX SUPPORT AS THR DETECTOR

Fumio MIZUTANI, Soichi YABUKI and Yoshiki HIRATA

National Institute of Bioscience and Human-Technology
1-1 Higashi, Tsukuba, Ibaraki 305, Japan

The concentration of L-lactic acid or glucose is determined by a combination of flow injection analysis with amperometric sensor detection. The enzyme sensor is prepared by immobilizing an enzyme (lactate oxidase for measuring L-lactic acid or glucose oxidase for glucose) in a layer of polyion complex consisting of poly-L-lysine and poly(4-styrenesulfonate).
The L-lactate sensor-based system can be used for the determination of L-lactate concentration up to 6 mM with a sampling rate of 120 samples/h, and is stable for 8 weeks after 1,000 L-lactate injections. The permselectivity of the polyion complex matrix is effective for reducing the response from electrochemical interferents such as L-ascorbic acid, uric acid and acetaminophen. The system can be used for the assay of L-lactic acid in non-diluted serum samples.
The glucose sensor-based system is also stable and can be applied to the determination of the analyte in non-diluted sera.

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2.
グルコースオキシダーゼ固定化 N-置換ポリピロール/ナフィオン薄膜電極
の作製及びセンサへの応用 (II)

安澤幹人、贄田崇志、椚　章

徳島大工

PREPARATION AND CHARACTERIZATION OF N-SUBSTITUTED POLYPYRROLE/NAFION THIN FILM ELECTRODE HAVING IMMOBILIZED GLUCOSE OXIDASE (II)

Mikito YASUZAWA, Takashi NIEDA and Akira KUNUGI

Department of Chemical Science and Technology, Faculty of Engineering, University of Tokushima
2-1 Minami josanjima, Tokushima, Japan

Glucose sensors having immobilized glucose oxidase (GOD) were prepared by the electropolymerization of 1-pyrrole propionic acid in the presence of GOD and then immersion in a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride solution. This glucose sensor showed good linear correlations between the glucose concentration and the response current density in the range of 0-6 mM glucose and offered stable response for over 50 days. By the placement of the Nafion film inside the GOD immobilizing film, the interference of acetaminophen with glucose response was significantly inhibited. However, the influence of ascorbic acid and uric acid was still significant.

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3.
高強度白金黒電解析出法を用いたマイクログルコースセンサの開発

池田章一郎、渡辺浩和、五十嵐伊勢美^*

名工大、豊田理研^*

DEVELOPMENT OF A MICRO GLUCOSE SENSOR USING AN ELECTRODEPOSITED PLATINUM BLACK WITH MECHANICAL STABILITY

Shoichiro IKEDA, Hirokazu WATANABE and Isemi IGARASHI^*

Department of Applied Chemistry, Nagoya Institute of Technology
Showa-ku, Nagoya 466, Japan
^* Toyota Physical and Chemical Research Institute
Nagakute-cho, Aichi-gun 459, Japan

The key point of the development of the implantable artificial pancreas is that of a small implantable glucose sensor which can measure blood glucose levels directly for a long time. We have proposed an in situ ultrasonic cleaning method to remove the adhered materials on the sensor surface from blood or body fluid. We have developed a micro glucose sensor fabricated in a needle using a newly developed electrodeposition method of Pt black with physical stability. Pt black was electrodeposited on a Pt wire (0.127 mmφ) sealed in a 23-G needle (ID = 0.45 mmφ) under irradiation of ultrasonic wave (38 kHz, 30 W) from a conventional Pt-electroplating solution for 80 s at -80 mV vs. Ag-AgCl. Pt black tightly adhered on the surface of a Pt wire, while that deposited without the irradiation of ultrasonic wave was easily removed from the surface by sonication. GOD was adsorbed to the Pt black surface from 0.75 ml of 5300 U/ml solution (pH 7.45) at 6℃ for 30 min and air-dried. GOD was fixed with glutaraldehyde and then with Nafion solution at 6℃. The activity of GOD immobilized on the Pt black was found to be 5.5 mU/sensor on the first day and it gradually decreased with time but kept more than 74% of the initial value after 26 days storing in PBSS at 6℃. The sensor responds to the stepwise change of glucose concentrations up to about 50 mg/dl within a few minutes and the output currents varied with oxygen partial pressures.

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4.
サクシニル化アビジンを利用したグルコースセンサー妨害物質の排除

星　友典、安斉順一、長　哲郎

東北大薬

ELIMINATION OF INTERFERENCES ON GLUCOSE SENSORS BY USING SUCCINYLATED AVIDIN

Tomonori HOSHI, Jun-ichi ANZAI and Tetsuo OSA

Pharmaceutical Institute, Tohoku University
Aobayama, Aobaku, Sendai 980-77, Japan

Avidin was succinylated and changed from basic to acidic protein. The succinylated avidin was electrodeposited on Pt and then biotinylated glucose oxidase was immobilized on the electrode via the avidin layer to prepare glucose sensor. Since both ascorbate and succinylated avidin have negative charge around pH 7, ascorbate is hard to pass through the avidin layer. The sensor can be used to detect glucose quantitatively in the presence of ascorbate (0.1 mM). The result suggests that the modification of avidin with succinyl residues is useful to decrease the effect of such interferences as ascorbate and uric acid.

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5.
表面プラズモン共鳴を用いたエイズウイルス糖タンパク gp41 抗体
のセンシングと血清の影響

窪田就彦、一二三恵美、宇田泰三

広島県立大生物資源

SENSING OF THE ANTIBODY AGAINST AIDS VIRUS PROTEIN gp41 AND THE INFLUENCE OF SERUM USING SURFACE PLASMON RESONANCE

Naruhiko KUBOTA, Emi HIFUMI and Taizo UDA

School of Bioresources, Hiroshima Prefectural University
Shoubara-shi, Hiroshima 727, Japan

One of the AIDS virus envelope protein, gp41, and its antibody were employed in a study about an AIDS sensor using surface plasmon resonance. In the sensor, anti gp41 antibody could be detected ranging from 1 to 20μg/ml. The immunoreaction was monitored in real time and the affinity constant Ka was easily determined from the kinetics as being 2.7×10⁷/M by processing the data inputted in a computer. The influence of scrum on the reflectance was examined for the purpose of practical application. Huge effects were observed in the scrum. Human serum influenced both the sensitivity to and the detection range for the antibody in SPR measurement. However, the antibody in the human sera samples could be quantitatively detected.

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6.
電気化学発光法による免疫測定

薛　蒙得、小畠英理、春山哲也、相澤益男

東工大・生命理工

ELECTROCHEMICAL LUMINESCENCE-BASED HOMOGENEOUS IMMUNOASSAY

Mengde XUE, Eiry KOBATAKE, Tetsuya HARUYAMA and Masuo AIZAWA

Department of Bioengineering, Tokyo Institute of Technology
Nagatsuta, Midori-ku, Yokohama 226, Japan

Electrochemically active substances such as luminol, which generate photons on the electrode surface, were employed as immunoassay labels. Luminol was found to exhibit electrochemical luminescence (ECL) in an aqueous solution containing hydrogen peroxide by electrochemical oxidation. Furthermore, ECL of antibody-attached luminol was found to be inhibited upon immunocomplexation, which facilitated a highly sensitive homogeneous immunoassay. Using this principle, a homogeneous immunoassay based on ECL was performed for α-fetoprotein (AFP). Under the optimal conditions, AFP was detected in the concentration range from 10^-9 to 10^-7 g/ml.

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7.
電解重合ポリピロール/ウレアーゼ-ポリアクリル酸重複膜を利用した尿素センシング

駒場慎一、瀬山倫子、田辺克久、逢坂哲彌

早大理工・早大材料技術研

UREA BIOSENSING SYSTEM USING A COMPOSITE FILM OF UREASE-POLYACRYLIC ACID/ELECTROPOLYMERIZED POLYPYRROLE

Shin-ichi KOMABA, Michiko SEYAMA, Katsuhisa TANABE and Tetsuya OSAKA

Department of Applied Chemistry, School of Science and Engineering;
Kagami Memorial Laboratory for Materials Science and Technology, Waseda University
3-4-1 Okubo, Shinjuku-ku, Tokyo 169, Japan

A potentiometric biosensor for urea was constructed as follows: insulating polypyrrole was grown from an aqueous solution of pyrrole and NaHCO₃ on the urease-polyacrylic acid coated Pt electrode, where polyacrylic acid combining chemically with urease by the synthesis of water soluble carbodiimide was already pretreated. This method could increase the immobilized ureases and the prepared electrode showed a good Nernstian response to urea.

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8.
リナマラーゼと GOD を用いたリナマリンセンサー

立間　徹、谷康一郎、小山　昇、H. H. YEOH^*

東京農工大工、シンガポール大^*

LINAMARIN SENSORS WITH LINAMARASE AND GLUCOSE OXIDASE

Tetsu TATSUMA, Koichiro TANI, Noboru OYAMA and Hock Hin YEOH^*

Department of Applied Chemistry, Faculty of Technology, Tokyo University of Agriculture and Technology
Koganei, Tokyo 184, Japan
^* Department of Botany, National University of Singapore
Kent Ridge, Singapore 0511, Republic of Singapore

Amperometric sensors for linamarin, a cyanogenic glycoside, were fabricated. They were based on the detection of glucose liberated from the hydrolysis of linamarin by linamarase from cassava leaf. A linamarase-glucose oxidase bienzyme-modified SnO₂ electrode was observed to function at +900 mV vs. Ag/AgCl in a hydrogen peroxide detection mode, and could determine linamarin down to 10μM. On the other hand, a linamarase-glucose oxidase bienzyme-modified graphite electrode mediated by poly(N-isopropylacrylamide-co-vinylferrocene) responded to >0.2 mM linamarin at +500 mV vs. Ag/AgCl. A linamarase-glucose oxidase-peroxidase trienzyme electrode was also fabricated by coating a peroxidase-incorporated polypyrrole-modified Sn0₂ electrode with a linamarase-glucose oxidase cross-linked film. This trienzyme electrode was able to function at a mild potential of +150 mV vs. Ag/AgCl, and has a sensitivity of 5μM Iinamarin.

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特別講演 1.
アビジン－ビチオン法による酵素固定化の制御とバイオセンサーへの利用

安斉順一

東北大薬

CONTROLLED IMMOBILIZATION OF ENZYMES ON ELECTRODE BY MEANS OF AVIDIN/BIOTIN COMPLEXATION AND ITS APPLICATION TO BIOSENSORS

Jun-ichi ANZAI

Pharmaceutical Institute, Tohoku University
Aobayama, Sendai-shi, Miyagi 980-77, Japan

Enzyme monolayers and multilayers composed of avidin and biotin-labeled enzymes were prepared on the surface of electrode, through a strong affinity between avidin and biotin (binding constant: ca. 10¹⁵ M^-1). Immobilization of enzyme was performed simply by immersing the electrode in an avidin solution and enzyme solution alternately for 10-20 min. The enzyme multilayers were useful for the improvement of the performance characteristics of enzyme sensors. The output current of the enzyme sensors depended linearly on the number of enzyme layers deposited. It was also possible to deposit two different kinds of enzymes successively in a single multilayer. Glucose oxidase (GOx) and ascorbate oxidase (AsOx) were built into a multilayer structure on a Pt electrode. The GOx/AsOx multilayer-modified electrode was useful for the elimination of ascorbic acid interference of the glucose sensor.

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9.
QCM によるバイオアフィニティー測定

尹　奎植、春山哲也、小畠英理、相澤益男

東工大生命理工

BIOAFFINITY SENSING BY QUARTZ CRYSTAL MICROBALANCE

Kyusik YUN, Tetsuya HARUYAMA, Eiry KOBATAKE and Masuo AIZAWA

Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology
Nagatsuta, Midori-ku, Yokohama 226, Japan

Immunoglobulin G (IgG) sensing and biotin sensing were monitored by a flow quartz crystal microbalance (QCM) cell system. IgG sensing was done by a protein A coated QCM. These two types of modified quartz crystal, with a fundamental resonant frequency of 6 MHz, were positioned in a thermostated flow cell. The resonant frequency was measured in a continuous flow mode. In the system, frequency change was observed by binding of IgG to the immobilized protein A. In the case of biotin sensor, avidin coupled with desthiobiotin on the crystal surface was replaced due to bioaffinity bonding to free biotin of solution and then frequency was changed to the biotin concentration. The sensor could be responded rapidly to the corresponding analyte on-line analysis in the flow conditions and without the use of labeled reagents.

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10.
水晶振動子を用いた化学センサーの基礎的研究
－飽和アルコールのアルキル鎖の効果－

渡辺剛大、神崎　榿、田中龍夫、榎本秀一^*

昭和薬科大学薬学部、理化学研究所^*

FUNDAMENTAL STUDY OF CHEMICAL SENSOR USING LIPID COATED QUARTZ CRYSTAL RESONATORS
- EFFECT OF ALKYL CHAIN ON THE ADSORPTION OF n-ALKYL ALCOHOLS -

Yoshihiro WATANABE, Yasushi KANZAKI, Tatsuo TANAKA and Shuichi ENOMOTO^*

Faculty of Pharmacy, Showa College of Pharmaceutical Sciences
Higashi-Tamagawagakuen, Machida, Tokyo 194, Japan
^* The Institute of Physical and Chemical Research
Hirosawa, Wako, Saitama 351-01, Japan

The quartz crystal resonator was adopted to investigate the hydrophobic interaction between the host lipid bilayers and the guest alkyl chains. The adsorption profile of n-alkyl alcohol with carbon number between 2 to 10 was examined on lipid coated quartz crystal resonator. The adsorption profile of the alcoholes at hydrogenated phosphatidylcholine (H-PC) bilayers increased gradually with increasing the carbon number and a steep increase was observed at carbon number of 10. On the other hand. the adsorption profile at dipalmitoylphosphatidylcholine (DPPC) bilayers indicated a maximum at carbon number of around 5 and 6. The appreciable difference was ascribed to the difference in the nature of the double alkyl chains of the host lipids.

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11.
麝香におい物質の水晶発振子の応答

載　小英、神崎　榿、田中龍夫、榎本秀一^*

昭和薬科大学薬学部、理化学研究所^*

RESPONSE OF MUSCONE ODOROUS SUBSTANCE BY USING QUARTZ CRYSTAL MICRO BALANCE

Xiao Ying DAI, Yasushi KANZAKI, Tatsuo TANAKA and Shuichi ENOMOTO^*

Faculty of pharmacy, Showa College of Pharmaceutical Sciences
Higashi -Tamagawagakuen Machida Tokyo 194, Japan
Shuchi Enomoto
^* The Institute of Physical and Chemical Research
Hirosawa, Wako, Saitama 351-01, Japan

Various adsorption behavior of odorant molecules were examined on quartz crystal resonator (QCR) coated by dipalmitoylphosphatidylcholine (DPPC), hydrogenated phosphatidylcholine (H-PC), phosphatidylcholine (PC), phosphatidylethanolamine (PE), and lysophosphatidylcholine stearoyl (LYSOPE). Various types of frequency response were revealed on the adsorption of muscone and limonene odorants. Anomalous behavior was observed on DPPC, LYSOPE, and PE coated QCR. The frequency to muscone adsorption on DPPC and LYSOPE linearly increased with increasing the adsorption amount contrary to the ordinary adsorption. The resonance frequency for limonene adsorption on PE linearly decreased with increasing the adsorption amount followed by the steep re-increase in frequency which resulted in the off-controlled resonance.

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12.
酵素電極の寿命に対する電位印加の影響

立間　徹、有山　薫、小山　昇

東京農工大工

EFFECTS OF POTENTIAL APPLICATION ON THE LIFETIME OF ENZYME ELECTRODES

Tetsu TATSUMA, Kaoru ARIYAMA and Noboru OYAMA

Department of Applied Chemistry, Faculty of Technology, Tokyo University of Agriculture and Technology
Koganei, Tokyo 184, Japan

Effects of potential application on the lifetime of enzyme electrodes were investigated using pyrolytic graphite electrodes on which glucose oxidase or lactate oxidase was adsorbed. Lifetime of LOD/BPG electrodes poised at +0.4 V vs. Ag/AgCl during storage was shorter than that of the electrodes at an open circuit potential (ca. +0.1 V vs. Ag/AgCl). This difference might be ascribed to a potential-dependent stability of LOD. In view of this, electrochemical oxidation of amino acids was studied.

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13.
複合酵素包括ポリピロール電極の作製条件と保存安定性の検討

渡辺　正、吉田章一郎、鈴木一路

東大生研

FABRICATION CONDITIONS AND STORAGE STABILITY OF POLYPYRROLE-ENCAPSULATED BIENZYME ELECTRODES

Tadashi WATANABE, Shoichiro YOSHIDA and Kazuro SUZUKI

Institute of Industrial Science, University of Tokyo
Roppongi, Minato-ku, Tokyo 106, Japan

Amperometric hydrogen peroxide and D-glucose sensors were fabricated by depositing horseradish peroxidase (HRP) or two enzymes of HRP and glucose oxidase (GOD) on the tin oxide (SnO₂) surface by means of encapsulation into electropolymerized pyrrole (PPy). After optimization for the PPy formation conditions, HRP/PPy and GOD/HRP/PPy electrodes gave nearly linear responses to l0^-7-l0^-4 M H₂O₂ and l0^-6-l0^-3 M D-glucose, respectively. Though the sensitivity of the electrodes prepared decreases slowly with time, the enzyme-incorporated PPy film exhibited good stability, when stored in pH 6.4 buffer solution at 4℃. The lowering of sensitivity during storage can be attributed to a decrease in the conductivity of PPy film, the leaching of the enzyme from the PPy film and the loss in apparent activity of entrapped enzyme in PPy film.

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14.
アレルゲンのフロー検出システムの作製

林　泰圭、中村徳幸、松永　是

東京農工大工

CONSTRUCTION OF A FLOW TYPE DETECTION SYSTEM FOR ALLERGEN

Tae-kyu LIM, Noriyuki NAKAMURA and Tadashi MATSUNAGA

Department of Biotechnology, Tokyo University of Agriculture and Technology
Koganei, Tokyo 184, Japan

An allergen detection system was developed based on a fluorescence immunoassay with a flow injection. Allergen and FITC conjugated IgE antibody solution were mixed and analyzed using a cation exchange column. Immunoreactions reached equilibrium within 20 min. The allergen-antibody complex was separated from free FITC conjugated antibody by using this column. The fluorescence intensity correlated linearly with a concentration of allergen in the range of O-2 mg/ml. Selectivity of this detection system was satisfactory. This simple, rapid and convenient immunoassay method can detect allergen continuously.

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15.
固定化サーモリシンの亜鉛(II)イオン識別素子への適用

佐藤生男、木暮美智、片岡由規美

神奈川工科大学・工業化学工学科

APPLICATION OF IMMOBlLIZED THERMOLYSIN AS A RECOGNITION ELEMENT FOR ZlNC(II) IONS

Ikuo SATOH, Michi KOGURE and Yukimi KATAOKA

Department of Chemical Technology, Faculty of Engineering,Kanagawa Institute of Technology
1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken 243-02, Japan

Photometric microdetermination of zinc(II) ions in flow streams was investigated with use of thermolysin covalently immobilized on porous glass beads. The FIA system was assembled with the beads-containing column mounted in a water-jacketed holder and a UV-detector with a flow-through cell for measuring the enzyme activity. Change in absorbance at the outlet of the column was successively monitored and recorded. The metal-free enzyme (apoenzyme) was regenerated by exposing the column to 0.1 M EDTA solution (pH 4.0). Zinc(II) ions in a range of 1μM to 2 mM were determined through the activation of the immobilized apoenzymes.

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17.
光導波路に基づいた高感度な屈折率センサーの開発

陳　暁民、卿　徳奎、伊藤公紀、村林眞行

横浜国大・環境研

A HIGHLY SENSITIVE SENSOR FOR REFRACTIVE INDEX OF SOLUTION BASED ON A COMPOSITE OPTICAL WAVEQUIDE

Xiaomin CHEN, Dekui QING, Kiminori ITOH and Masayuki MURABAYASI

Institute of Environmental Science and Technology, Yokohama National University
Tokiwadai, Hodogayaku, Yokohama 240, Japan

A highly sensitive composite optical waveguide was developed by combining a thin TiO₂ film with a K⁺-doping glass optical waveguide. The sensitivity of the film surface was extremely high, more than several thousand times per unit optical length, when the adiabatic transition was successfully operated. Furthermore, the sensitivity was associated with the change of refractive index of clad layer (n_c). With this principle, the refractive index of the clad can be sensitivily monitored, and the sensitivity was estimated to be temporarily △ n_c <10^-5.

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18.
ルテニウム電極を用いた CO₂センサ

飯島鉄也、石地　徹

理研計器

ELECTROCHEMICAL GAS SENSOR USING RUTHENIUM OXIDE FOR DETECTION OF CARBON DIOXIDE

Tetsuya IIJIMA and Toru ISHIJI

Riken Keiki Co., Ltd.
2-7-6 Azusawa, Itabashi-ku, Tokyo 174, Japan

An amperometric carbon dioxide sensor based on the pH-dependent reduction of ruthenium oxide (RuO₂ sensor) was evaluated comparing with platinum oxide one (PtO sensor). The ruthenium oxide electrode was formed on a gas permeable membrane by a printing method. The reduction current of the RuO₂ sensor was a hundred times larger than that of a PtO sensor. The linear relationship of RuO₂ sensor between the reduction current and the CO₂ concentration was observed in the range from 0 to 500 ppm. The RuO₂ sensor shows less influence for coexisting gases comparing with a PtO sensor. Difference of the characteristics between RuO₂ and PtO sensor would be caused by the reaction properties and the structure of the diffusion electrode of the sensor.

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19.
Crテトラフェニルポルフィリン薄膜を用いた SAW 型 NO₂センサ

花里善夫、神谷俊行、木村さおり、宮本　誠、磯田　悟^*

三菱電機先端総研・本社^*

SURFACE ACOUSTIC WAVE GAS SENSOR FOR NITROGEN DIOXIDE USING THIN FILM OF Cr-TETRAPHENYLPORPHYRIN

Yoshio HANAZATO, Toshiyuki KAMIYA, Saori KIMURA, Makoto MIYAMOTO and Satoru ISODA^*

Advanced Technology R&D Center, Mitsubishi Electric Corp.,
1-1 Tsukaguchi-Honmachi 8-Chome, Amagasaki, Hyogo 661, Japan
^* Head Office, Mitsubishi Electric Corp.
Marunouchi 2-2-3, Chiyodaku, Tokyo 100, Japan

A highly sensitive nitrogen dioxide sensor has been developed. The sensor consists of Cr-tetraphenylporphyrin thin film acting as a gas sensitive membrane and a surface acoustic wave (SAW) device as a signal transducer. The concentration of nitrogen dioxide in the range of 27 ppb - 10 ppm was detectable by the sensor with good selectivity (the sensor was insensitive to CO (50 ppm), CO₂ (1 %), n-butane (50 ppm) and NO (10 ppm)) at 125℃. The stability of the sensor and the effect of humidity on the sensor sensitivity were also described.

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20.
QCM 法による N,N-ジメチルアミノメタクリレートポリマーへの
酸性ガスの可逆的吸脱着の測定

酒井義郎、横内洋文、定岡芳彦、松口正信

愛媛大・工

SORPTION OF ACID VAPOR ON N,N-DIMETHYLAMlNO METHACRYLATE POLYMER STUDIED BY QCM METHOD

Yoshiro SAKAI, Hirofumi YOKOUCHI, Yoshihiko SADAOKA and Masanobu MATSUGUCHI

Department of Applied Chemistry, Faculty of Engineering, Ehime University
Matsuyama, Ehime 790, Japan

The amount of sorbed acetic acid in poly(N,N-dimethylaminoethyl methacrylate) at various vapor concentrations was measured by the quartz microbalance (QCM) method. The electrical impedance was also measured at 1 kHz. In the low vapor concentration region below 350 ppm the QCM method is useful, while no impedance change was detected in that region. However, in the higher concentration the impedance increases linearly with the vapor concentration while the QCM method becomes less sensitive. The results were interpreted in terms of the dual sorption model assuming the coexistence of two types of sorption, that is, Henry type and Langmuir type sorption. The response time at low vapor concentrations was reduced by using copolymers with methyl methacrylate. The mechanism was also explained on the basis of the dual sorption assumption.

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21.
セラミックス表面への水蒸気の吸着現象を利用した起電力式湿度センサ

矢嶋　保、片平幸司、鎌田正裕^*、江坂享男^*

TYK、鳥取大工

POTENTIOMETRlC TYPE HUMIDITY SENSOR USING ADSORPTION PHENOMENON OF WATER VAPOR ON THE SURFACE OF CERAMICS

Tamotsu YAJIMA, Koji KATAHIRA, Masahiro KAMATA^* and Takao ESAKA^*

Research and Development Center, TYK Co.
3-1 Ohbata-cho, Tajimi 507, Japan
^* Faculty of Engineering, Tottori University
Koyama-cho, Tottori 680, Japan

A new potentiometric type humidity sensor was fabricated using an adsorption phenomenon of water vapor on the surface of ceramics. The device having two kinds of different metal electrodes exhibited stable emf in water vapor included atmosphere at room temperature. The emf of this device depended on humidity and the combination of electrode materials. The response of this sensor was quick on changing P_H₂O.

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22.
ポリ(o-フェニレンジアミン)/ポリビニルアルコール複合膜を用いた湿度センサー

椎木　弘、中山雅晴、小倉興太郎

山口大工

POLY(o-PHENYLENEDIAMINE)/POLY VINYL ALCOHOL COMPOSITE FILM FOR HUMIDITY SENSOR

Hiroshi SHIIGI, Masaharu NAKAYAMA and Kotaro OGURA

Department of Applied Chemistry, Yamaguchi University
Tokiwadai, Ube 755, Japan

The conducting composite film has been prepared from conducting poly(o-phenylenediamine) (PoPD) and insulating poly(vinyl alcohol) (PVA). This composite film showed a very low value of the percolation threshold (0.1 vol% of the PoPD content) where the conductivity rised sharply. On the other hand, the conductivity of the prepared composite film was linearly related with the atmospheric humidity, extending from 10^-5 to 10^-1 S cm^-1.

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23.
鉛－、亜鉛－フタロシアニンの CO, H₂, CH₄ガス応答特性

兼房槙二、新田正義

日大生産工

RESPONSE PROPERTIES TO CO, H₂, CH₄ GASES BY LEAD- OR ZINC-PHTHALOCYANINES

Shinji KANEFUSA and Masayoshi NITTA

Physical Science Laboratories of Basic Sciences, College of Industrial Technology, Nihon University
Narashino-shi, Chiba-ken 275, Japan

Gas sensors, made of PbPc- and ZnPc-based sensors, have been prepared. Their sensitivities to CO, H₂ and CH₄ gases at various sensor temperatures have been investigated. It is found that the ZnPc- and PbPc-based sensors exhibit high sensitivity around at 170℃ and 70℃, respectively. It is also found that PbPc sensors mixed with 15 wt% RuO₂ and 1 wt% Pd behave as an n-type semiconductor to H₂ gas, even though pure PbPc is a p-type semiconductor.

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24.
電流制御測定法を用いたサスペンデッドゲート LAPS ガスセンサの高感度化

張　文芸、中沢宏聡、原　正史、内田秀和、勝部昭明
埼玉大工

HIGH SENSITIVE SUSPENDED-GATE LAPS GAS SENSOR WITH CURRENT CONTROLLED METHOD

ZHANG Wenyi, H. NAKAZAWA, H. UCHIDA and T. KATSUBE

Faculty of Engineering, Saitama University
255 Shimo-Okubo, Urawa-Shi, Saitama, 338, Japan

High sensitive measurement technique of suspended gate LAP (Light Adressible Potentiometric) gas sensor was proposed. It is based on a current controlled method different from the voltage controlled method of the conventional LAP system. The sensitivity enhancement was attained by the high input impedance of the controlled system which was confirmed by an oxygen gas sensor fabricated with sputtered LaF₃ as a gas sensitive film.

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25.
牛肉の鮮度評価を目指した半導体ガスセンサ用検知材料の探索

高橋　理、阿武裕一、玉置　純、浅野泰一^*、矢野幸男^**、三浦則雄、山添　曻

九大総合理工、電気化学計器^*、伊藤ハム^**

MATERIAL SEARCH FOR SEMICONDUCTOR GAS SENSOR FOR EVALUATING BEEF FRESHNESS

Osamu TAKAHASHI, Yuichi ANNO, Jun TAMAKI, Yasukazu ASANO, Yukio YANO, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyusyu University
Kasuga-shi, Fukuoka 816, Japan

Metal oxide-based sensors were exploited for detecting various odorous components produced in the process of aging and/or putrefaction of beef, such as ethyl acetate, iso-amylalcohol, acetoin, and so on. Among various sensor elements tested, MgO(5 wt%)-ZnO showed the highest sensitivity to ethyl acetete (20 ppm in wet air) at 400℃, though with rather poor selectivities against other components. Iso-amylalcohol could be detected most sensitively and selectively by WO₃(5 wt%)-ZnO at 500℃, whereas acetoine gas could be detected at excellent sensitivity and selectivity by WO₃(0.5 wt%)-ZnO and Eu₂0₃(5 wt%)-ZnO at 300℃ and 400℃, respectively. These elements, especially the last three, appear to be applicable to evaluation of beef eating quality.

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26.
ジメチルアミンガス検出特性に及ぼす部分分解生成物の酸化挙動

河口智博、高尾雄二^*、清水康博、江頭　誠

長崎大・工、海洋^*

ROLE OF PARTIAL DECOMPOSITION PRODUCTS OF DIMETHYLAMINE ON THE DIMETHYLAMINE GAS SENSING PROPERTIES OF 3.0Pt/In₂O₃-MgO(5 mol%)

Tomohiro KAWAGUCHI, Yuji TAKAO^*, Yasuhiro SHIMIZU, Makoto EGASHIRA

Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852, Japan
^* Graduate School of Marine Science and Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852, Japan

To clarify the reasons for higher sensitivity to dimethylamine (DMA) than trimethylamine (TMA) observed with a 3.0Pt/In₂O₃-MgO(5 mol%) sensor, analysis of oxidation behavior of these gases was performed simultaneously with the sensitivity measurements by employing a specially designed sensor structure. A large amount of C₂H₄NH and a small amount of NO₂ were found to be produced in the case of DMA, in comparison with the case of TMA, over the sensor material at 200℃ at which the sensor exhibited the maximum DMA sensitivity. In addition, the sensor exhibited higher sensitivity to C₂H₄NH than DMA. Thus, it is revealed that consumption of chemisorbed oxygen during the oxidation process of C₂H₄NH is also responsible for higher DMA sensitivity. Furthermore, the Pt loaded is suggested to act as an active adsorption site for C₂H₄NH and then to accelerate effectively the reaction with chemisorbed oxygen.

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27.
ZnO-SnO₂系複合酸化物のガス感度特性

平塚信之、清水政行、小林　裕、柿崎浩一

埼玉大理工学研究科

GAS SENSING CHARACTERISTICS OF ZnO-SnO₂ COMPOSITE OXIDES

Nobuyuki HlRATSUKA, Masayuki SHIMIZU, Hiroshi KOBAYASHI, and Koichi KAKIZAKI

Graduate school of Sci. and Eng., Saitama Univ.
255 Shimo-Ohkubo, Urawa, Saitama 338, Japan

The bulk gas sensors composed of various atomic ratios of ZnO and SnO₂ were fabricated to investigate their gas sensing characteristics. After the composite powders of ZnO and SnO₂ added with camphor as the same weight of the powders were pressed into disks, they were sintered at 1100℃, 1200℃ and 1300℃ for 3 hours in air. The relation between their surface structure and their gas sensing characteristics was investigated. As a result of the measurements of these gas sensors to exposure to 20000 ppm i-C₄H₁₀ gas, the sensor consisted of the spinel-type Zn₂SnO₄ with a small amount of SnO₂ enhanced the gas sensitivities.

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28.
Zn-Sn系酸化物薄膜のガス感度特性

小林　裕、平塚信之、内田秀和、勝部昭明

埼玉大理工

GAS SENSING CHARACTERISTICS OF Zn-Sn COMPOSITE OXIDE THIN FILMS

Hiroshi KOBAYASHI, Nobuyuki HlRATSUKA, Hidekazu UCHIDA and Teruaki KATSUBE

Graduate school of Sci. and Eng., Saitama Univ.
255 Shimo-Ohkubo, Urawa, Saitama 338, Japan

Zn-Sn metallic films were deposited on alumina substrates by an evaporation method, and then the composite oxide films were fabricated by annealing in air. We investigated the relation between the formation of spinel-type Zn₂SnO₄ and their gas sensing characteristics to i-C₄H₁₀ gas. Both ZnO and SnO₂ films annealed at 500℃ had higher sensitivity to i-C₄H₁₀ than the composite films of ZnO and SnO₂ because of fine crystallinity of these simple body films. The sensitivity of the composite films increased with annealing temperature, because the films had stable spinel-type structure.

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29.
SnO₂完全結晶のエネルギーバンド計算

松嶋茂憲、小林健吉郎、岡田元次、白方　祥、香山正憲^**

愛媛大工、大工研^**

ENERGY BAND STRUCTURE OF TIN DIOXIDE

Shigenori MATSUSHIMA, Kenkichiro KOBAYASHI, Genji OKADA, Sho SHIRAKATA^* and Masanori KOHYAMA^**

Department of Applied Chemistry, Faculty of Engineering, Ehime University
3-Bunkyo-cho, Matsuyama, Ehime 790, Japan
^* Department of Electrical and Electronic Engineering. Faculty of Engineering, Ehime University
3 Bunkyo-cho, Matsuyama, Ehime 790, Japan
^** Department of Material Physics, Osaka National Research Institute
1-8-31, Midorigaoka, Ikeda, Osaka 563, Japan

The energy band structure of SnO₂ is calculated by a tight binding (TB) method. In the calculation, only Sn-O interactions are considered, i.e., a nearest-neighbor approximation. The band gap has a width of 5.3 eV and the valence band maximum consists of four degenerate flat bands. An inclusion of the O-O interactions removes the degeneracies of the upper valence band. As the results, the upper valence band width is enlarged up to 9.7 eV and the energy gap is narrowed up to 4.0 eV. These values agree fairly with the experimental results.

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30.
酸化スズ半導体ガスセンサ材料の STM 観察

中川英元、作本弘司、土屋雅弘、棟方克夫^*、朝倉祝治、渡辺慎介、重盛徹志^**、福田健三

横浜国立大、横須賀工業高校^*、新コスモス電気^**

SCANNING TUNNELING MICROSCOPE OBSERVATION OF SINTERED TIN-DIOXIDE GAS-SENSING SEMICONDUCTOR

H. NAKAGAWA, K. SAKUMOTO, M. TSUCHIYA, K MUNAKATA^*, S. Asakura, S. WATANABE, T. SHIGEMORI^**, K. FUKUDA

Dept. of Mater. Sci. & Chem. Eng, Fac. of Eng, Yokohama National University,
Hodogaya Yokohama, 240, Japan
^* Yokosuka Technical Highschool
Yokosuka, Kanagawa, Japan
^** New Cosmos Electric Co., Ltd
Yodogawa, Osaka 532, Japan

Tin-dioxide gas sensing devices were fabricated with several impurities and sintering temperatures. Gas sensing characteristics of pure- and Ba-doped materials were investigated with C₂H₅OH, CO and H₂ gases, in correlation with the sintering temperatures and crystalline sizes. The result indicated that the gas sensitivity is strongly correlated with the crystalline sizes, whereas dopants affected the gas selectivity. STM observations in air and nitrogen atomosphere suggested the existence of surface-adsorbed oxygen. The effect of dopants on poly-crystalline morphology was also observed.

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特別講演 2.
次世代センサの要素技術

藍　光郎

日製エンジニアリング（株）

KEY TECHNOLOGIES OF SENSORS IN NEXT GENERATION

Mitsuo AI

AI Sensor Engineering Laboratory
Tokyo 136, Japan

There are major key technologies for developing sensors in next generation, which are micro technology, imaging technology and quantum/molecular technologies. Micro technology is expected, by adding thin film technology, to spread not only in physical sensors and actuators, but also in chemical sensors and many other applications. Imaging technology consists of pattern imaging, CT imaging and microscopic imaging. Quantum and molecular technologies are also useful in sensors of deep submicron and nanometer areas.

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31.
蒸着 WO₃薄膜の熱処理効果

中込真二、奥田佳彦、惠原貴志、山本達夫

石巻専修大理工

EFFECT OF HEAT TREATMENT OF WO₃ THIN FILM PREPARED BY VACUUM EVAPORATION

Shinji NAKAGOMI, Yoshihiko OKUDA , Takashi EHARA and Tatsuo YAMAMOTO

Department of Electronic materials, School of Science and Engineering, Ishinomaki Senshu University
Ishinomaki 986-80, Japan

Dependence of NO_x gas sensing characteristic of WO₃ thin film prepared by vacuum evaporation on heat treatment was studied. The heat treatment of 3 hours was performed at 400-800℃ in air. The electrical resistance at 300℃ of several elements that were treated at different temperature of heat treatment was compared in N₂, NO₂, NO, O₂ gases atmosphere. It was found that the resistance of WO₃ element decreases with increasing the temperature of heat treatment and the selectivity of NO₂ gas sensing from NO and O₂ gases increases with increasing the temperature of heat treatment. We compared the surface morphology of WO₃ thin film after heat treatment.

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32.
NO_x雰囲気におけるFe系及びCu系ペロブスカイト関連酸化物の導電率

尾浜宏之、長谷井政治^*、水崎純一郎^**、田川博章

横浜国大環科研セ、リケン^*、東北大科研^**

THE CONDUCTIVITY OF Fe- AND Cu-PEROVSKITE OXIDE IN NO_x ATMOSPHERE

Hiroyuki OHAMA, Masaharu HASEI^*, Junichiro MIZUSAKI^** and Hiroaki TAGAWA

Institute of Environmental Science and Technology Yokohama National Univ.
156 Tokiwadai, Hodogaya-ku, Yokohama 240, Japan
^* Riken Co.
4-14-1 Suehiro, Kumagaya-shi, Saitama 360, Japan
^* RISM, Tohoku Univ.
2-1-1 Katahira, Aoba-ku, Sendai 980-77, Japan

The conductivity of La_0.5Sr_0.5FeO_3-δ was measured in O₂-N₂, and NO_x-O₂-N₂ atmospheres at 755-85℃. The conductivity in O₂-N₂ atmospheres increased with the oxygen concentration, and was dependent on temperature. In NO₂-O₂-N₂ atmospheres, the conductivity increased with the NO₂ concentration. The variations in the conductivity with the NO₂ concentration were greater than those with the O₂ concentration. In NO-O₂-N₂ atmospheres, the conductivity did not change with NO concentration. Because NO₂ continuously decomposed on the surface of La_0.5Sr_0.5FeO_3-δ, the oxygen activity on the surface became extraordinary high, resulting in the decrease in the oxygen deficient nonstoichiometry and the increase of p-type conductivity.

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33.
ペロブスカイト型酸化物厚膜素子の NO_x検知特性

栗原香暁、田中伸一、杉山和夫

埼玉大工

NO_x SENSING PROPERTIES OF PEROVSKITE-TYPE OXIDE THICK FILM SENSORS

Yoshiaki KURIHARA, Shinichi TANAKA and Kazuo SUGIYAMA

Department of Applied Chemistry, Faculty of Engineering, Saitama University
255 Shimo-okubo, Urawa 338, Japan

Gas sensing properties of the perovskite-type oxide such as AFeO₃ (A= La³⁺, Nd³⁺, Sm³⁺) were investigated. The thick film (ca. 20μm) of the perovskite oxide which sintered on the α-alumina substrate was used for the sensor element device. The response of the device was measured in a stream of synthetic air at temperature range of 450 to 550℃. NO, NO₂, CO, CH₄ and H₂ gases were respectively used as detecting gases. SmFeO₃ thick film showed superior sensitivity to NO₂ and it was inactive for CO, CH₄ and H₂ gases at the temperature range of 450 to 500℃.

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34.
窒化ケイ素を母体とした窒素酸化物センサ

廣田洋平、今中信人、足立吟也

阪大工

NO_x SENSOR BASED ON SILICON NITRIDE

Yohei HIROTA, Nobuhito IMANAKA and Gin-ya ADACHI
Department of Applied Chemistry, Faculty of Engineering, Osaka University
2-1 Yamadaoka, Suita, Osaka 565, Japan

The NO_x (NO, NO₂) sensing characteristics of silicon nitride, Si₃N₄, were studied. The electrical resistivity of the sensor element decreased with the increase of both NO₂ and NO concentration at 850℃. The magnitude of the response to NO₂ was twice as high as that to NO. The time necessary to attain 90% response was approximately 10 min for both cases. The interference of O₂ gas content variation toward NO₂ sensing was greatly suppressed in the NO₂ existing atmosphere.

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35.
プロトン導電体を用いた NO センサ

原田達朗、来仙貴久、三浦則雄、山添　曻

九大総合理工

NO SENSOR USING PROTON-CONDUCTOR

Tatsuro HARADA, Takahisa RAISEN, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

Solid-state electrochemical devices using proton-conductive antimonic-acid were examined for detecting a small amount of NO in air at room temperature. Two types of sensor devices were fabricated by using a disc or a thick film of antimonic acid. As a sensor signal, the electric current through the proton conductor was measured under the condition in which the external voltage was applied between the sensing and the reference electrodes. The current response of the sensor was found to be almost linear to NO concentration in the range of 0-100 ppm. In addition, by selecting the applied voltage, it was possible to differentiate NO and NO₂ selectively. A small planar-type device using the thick film was also found to give fairly good sensing properties. The NO_x sensing mechanism of the present sensor was briefly discussed .

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36.
薄膜プロトン導電体を用いた限界電流式センサ

稲葉忠司、高橋英昭、佐治啓市、増岡優美

豊田中研

LIMITING-CURRENT SENSOR USING PROTON CONDUCTOR THIN-FILM

Tadashi INABA , Hideaki TAKAHASHI, Keiichi SAJI, Yumi MASUOKA

Toyota Central Research & Development Labs., Inc.
Nagakute , Aichi 480-11, Japan

To obtain CaZr_0.9In_0.1O_3-α proton conductor thin-film and to construct a limiting-current hydrogen sensor, the sputter method was investigated. The perovskite structure film was obtained by sputtering in Ar and heat-treatment at 800℃ in air. A hydrogen concentration cell with this film showed theoretical EMF at temperatures from 500℃ to 900℃. Therefore this film was regarded as proton conductor. A limiting-current hydrogen sensor was constructed using this film. The sensor showed limiting-current corresponding to partial pressure of hydrogen. In the hydrogen partial pressure range below 0.01 atm, a linear relationship between limiting-current and hydrogen partial pressure was obtained.

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37.
薄膜全域空燃比センサ

高橋英昭、稲葉忠司、近藤春義、増岡優美、佐治敬市

豊田中研

THIN-FILM WIDE-RANGE AIR-FUEL RATIO SENSOR

Hideaki TAKAHASHI, Tadashi INABA, Haruyoshi KONDO, Yumi MASUOKA and Keiichi SAJI

Toyota Central R&D Labs. Inc.
41-1 Yokomichi, Nagakute, Aichi 480-11, Japan

An experimental thin-film wide-range air-fuel ratio sensor has been fabricated on a porous alumina substrate. The sensor consists of an oxygen pump cell and a limiting-current cell on the substrate. These cells were laminated in the order, Pt/ZrO₂ electrolyte/Pt/ZrO₂ electrolyte/Pt using a sputtering apparatus. In this sensor, the oxygen pump cell served to supply oxygen to the limiting-current cell as an alternate function of air introduction. Consequently, the output current of the limiting-current cell applied with a constant voltage of 0.6 V revealed that air ratio of 0.7-1.5 could be continuously measured.

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38.
薄膜ジルコニア空燃比センサ（第二報）

鈴木隆之、二田穂積

矢崎計器

THIN-FILM ZIRCONIA AIR TO FUEL RATIO SENSOR (2)

Takayuki SUZUKI and Hozumi FUTATA

Yazaki Meter Co., Ltd., Gas Equipment Development Department
23 Minamikashima, Futamata-cho, Tenryu-shi, Shizuoka 431-33, Japan

Thin-film zirconia sensor based upon a porous alumina substrate has a good linearity output for oxygen concentration in oxidation combustion exhaust and for hydrogen concentration in reduction combustion exhaust in the case of the alternating current applied to the electrolytic cell.
A long-term stability of this sensor has been investigated. In the result, it has a stabilized output in the case of the oxidation-reduction cyclic test, so the output is object of the characteristics of the limiting-current region only.

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39.
LaGaO₃系ペロブスカイト型酸化物を電解質とする低温作動型酸素センサ

石原達己、樋口正和、西口宏泰、滝田祐作

大分大工

REDUCED TEMPERATURE OXYGEN SENSOR WHERE LaGaO₃ PEROVSKITE OXIDE USED AS ELECTROLYTE

Tatsumi ISHIHARA, Masakazu HIGUCHI, Hiroyasu NISHIGUCHI and Yusaku TAKITA

Department of Applied Chemistry, Faculty of Engineering, Oita University
Dannoharu 700, Oita 870-11, Japan

Oxygen sensor operated in the decreased temperature range was investigated by applying the LaGaO₃ based oxide for electrolyte, since LaGaO₃ based oxide exhibits the extremely high oxide ion conductivity. The electromotive forces as well as the limit of lower operating temperature were strongly dependent on the electrode catalysts, and it became evident that silver is the most suitable as the electrode materials for the oxygen sensor where LaGaO₃ based oxide was applied. On the element where La_0.8Sr_0.2Ga_0.8Mg_0.2O₃ and Ag were applied for electrolyte and electrode, respectively, the electromotive forces were dependent on the oxygen concentration above the temperature of 330℃. Consequently, LaGaO₃ based oxide is the promising electrolyte for the oxygen sensor in the decreased temperature range.

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40.
安定化ジルコニアと酸化物電極を組み合わせた硫化水素センサ

廬　革宇、巌　永鉄、三浦則雄、山添　曻

九大総合理工

HYDROGEN SULFIDE SENSOR USING COMBINATION OF STABILIZED ZIRCONIA AND METAL OXIDE SENSING ELECTRODE

Geyu LU, Yongtie YAN, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

New type electrochemical sensors for H₂S were developed by combining a Y₂O₃-stabilized zirconia (YSZ) tube with a sensing oxide layer of WO₃. The sensor device composed was an electrochemical cell of the form, air, Pt ｜ YSZ ｜ WO₃, Pt, H₂S (+air). This device was found to respond well to 0.2-25 ppm H₂S in air at 400℃, with acceptable response rates. The EMF of the sensor was linearly related to the logarithm of H₂S concentration. In addition, the EMF was hardly affected by the coexistence of CO₂ and water vapor. Based on the measurement of anodic and cathodic polarization curves, the H₂S sensing signal was suggested to reflect the mixed potential at the YSZ/WO₃ interface.

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41.
固体電解質の接合を利用した水素センサ

片平幸司、矢嶋　保、志村哲生^*、岩原弘育^*

TYK、名大理総^*

HYDROGEN GAS SENSOR USING JOINTED SOLID ELECTROLYTES

Koji KATAHIRA, Tamotsu YAJIMA, Tetsuo SIMURA^* and Hiroyasu IWAHARA^*

TYK Corporation, Research and Development Center
3-1 Ohbata-cho, Tajimi 507, Japan
^* Center for Integrated Research in Science and Engineering, Nagoya University
Furo-cho, Chikusa-ku, Nagoya 461-01, Japan

To develop a new sensor for the detection of hydrogen gas in the air, we proposed solid electrolyte device which joined a proton conductor layer with an oxide ion conductor by the diffusion reaction method. The proton conductor layer has been adhered firmly and uniformly to the oxide ion conductor. The different electrode reactions took place at each electrode attached to proton conductor and oxide ion conductor. Using this character, hydrogen gas sensor was fabricated without standard material. The sensor EMF varied logarithmically with hydrogen concentration.

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