Vol. 12, Supplement B (1996)

Vol. 12, Supplement B (1996)

Proceedings of the 23rd Chemical Sensor Symposium
September 17-18, 1996
Ritsumeikan University

Abstracts

1. 酵素活性阻害に基づくシアンセンサーとリナマリンセンサーの開発

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^*

DEVELOPMENT OF INTERFERENCE-BASED BIOSENSORS FOR CYANIDE AND LINAMARIN

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

An inexpensive and reagentless interference-based biosensor for cyanide is developed using pyrolytic graphite electrode on which peroxidase is adsorbed. Catalytic activity of peroxidase toward hydrogen peroxide, which is generated at the graphite surface by electrochemically reducing dissolved oxygen, is inhibited by cyanide. The sensor is then coated with a cross-linked linamarase film for the determination of a cyanogenic glycoside, linamarin. The linamarin sensor can determine 10μM to 5 mM linamarin and can estimate a linamarin concentration of a cassava extract.

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2. サーモリシン由来のアポ酵素を用いた亜鉛(II)イオンのバイオセンシング

佐藤生男、木暮美智

神奈川工科大学応用化学科

BIOSENSIHNG OF Zn(II) IONS USING THE APOENZYMES REGENERATED FROM THERMOLYSIN

Ikuo SATOH and Michi KOGURE

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

Flow-injection photometric determination of zinc(II) ions was tested using thermolysin covalently immobilized on porous glass beads. The sensing system was assembled with the beads-containing column and a UV-detector for monitoring the enzyme activity. Variation in absorbance at the outlet of the column was continuously measured. Regeneration of the apoenzyme, that is, metal-free enzyme was made by exposing the column to 0.1 M (M=mol dm^-3) EDTA solution (pH 4.0) as the chelating agents. Zinc(II) ions in a range of 0.1μM to 5 mM were determined thRough the activation of the apoenzyme column.

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3. フローインジェクションシステムを用いた食物アレルゲンの連続モニタリング

中村徳幸、林　泰圭、松永　是

東京農工大工

CONTINUOUS MONITORING OF FOOD ALLERGEN USING FLOW INJECTION SYSTEM

Noriyuki NAKAMURA, Tae-kyu LIM and Tadashi MATSUNAGA

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

Continuous monitoring based on a luminescence immunoassay with flow injection system was performed. Food allergen and alkaline phosphatase (ALP)-conjugated IgE antibody were incubated and analyzed using an anion exchange column. The allergen-antibody complex was separated from free ALP-conjugated antibody. ALP-conjugated IgE and food allergen complex can be continuously monitored from the luminescence. Immunoreactions reached equilibrium within 15 min. The output correlated linearly with a concentration of allergen in the range of 0.2-100μg/ml. This simple, rapid, and convenient immunoassay method can detect allergen continuously.

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4. ディスポーザブルバイオセンサの培養液管理への応用

宮原万里子、三浦重信^*、池田恵子^*、青田とも子^**、金子光範^***、辻　里子、吉岡俊彦、南海史郎

松下電器産業、武蔵野化学研究所^*、エイブル^**、バイオット^***

DETERMINATION OF D-GLUCOSE AND L-LACTATE IN CULTURE MEDIUM BY DISPOSABLE BIOSENSORS

Mariko MIYAHARA, Shigenobu MIURA^*, Keiko IKEDA^*, Tomoko AOTA^**, Mitsunori KANEKO^***, Satoko TSUJI, Toshihiko YOSHIOKA and Shiro NANKAI

Matsushita Electric Industrial Co., Ltd.
3-1-1 Yagumo-nakamachi, Moriguchi, Osaka 570, Japan
^* Musashino Chemical Laboratory Ltd.
1-16-2 Miyamae, Suginami-ku, Tokyo 168, Japan
^** Able Corporation
76-1 Kamitogari, Nagaizumi-cho, Suntou-gun, Shizuoka 411, Japan
^*** Biott Corporation
6-10 Nishigoken-cho, shinjuku-ku, Tokyo 162, Japan

A disposable biosensor for the determination of glucose or L-lactate in culture medium is described. The sensors are based on screen-printed carbon electrode coupled with enzyme and hexacyanoferrate(III) as an electron mediator. Enzymes used were glucose oxidase for glucose sensor and lactate oxidase for L-lactate. Hexacyanoferrate(II) produced in the above enzyme reactions was monitored amperometrically on the carbon electrode.
Linear relationship between sensor responses and concentration of each analytes was obtained up to 0.04 wt% using 5μL of sample. These biosensors were applied to the determination of analytes in animal cell culture medium and in fermentation of lactic acid, good agreements with the results of conventional methods were obtained.

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5. 制限透過膜を積層したアンペロメトリック型ワンチップグルコースセンサの開発

松本　達、古澤真抄子、伊藤成史

NEC資源環境技術研究所

DEVELOPMENT OF A ONE-CHIP AMPEROMETRIC GLUCOSE SENSOR WITH MULTILAYER POLYMER FILMES

Toru MATSUMOTO, Masako FURUSAWA, Narushi ITO

Resources and Environment Protection Research Laboratories, NEC Corporation
4-1-1 Miyazaki, Miyamae-ku, Kawasaki-shi, Kanagawa 216, Japan

Reported here is a newly developed one-chip amperometric glucose sensor capable of measuring glucose concentrations in body fluids without diluting themselves. The sensor consists of a working electrode made of platinum, a reference electrode made of Ag/AgCl, and a counter electrode made of platinum, all fabricated on a quartz substrate and coated with five membranes. Four of these are diffusion membranes, and one is an enzyme membrane (glucose oxidase membrane).
Tests of the sensor demonstrate its imperviousness to the effects of both ascorbic acid (<200 mg/dl) and uric acid (<5mg/dl), as well as its capability of accurately and consistently determining glucose concentrations in those acids ranging from 50 to 600 mg/dl. And then the sensor response time is ranging form 10 to 20 seconds.

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6. 使い捨て型グルコースセンサの応答特性

宮本佳子、池田　信、吉岡俊彦、南海史郎

松下電器産業（株）研究本部

CHARACTERIZATION OF DISPOSABLE GLUCOSE SENSOR

Yosiko MIYAMOTO, Shin IKEDA, Toshihiko YOSHIOKA, and Shiro NANKAI

Corporate Research Division, Matsushita Electric Industrial Co., Ltd.
Moriguchi-shi, Osaka 570, Japan

In this study, we examined a characteristics of a disposable glucose sensor. A reagent layer was formed by two kinds of layer onto the electrode system of the sensor. The bottom one was a carboxymethyl celllulose (CMC) layer, and the upper one was a mix layer containing glucose oxidase (GOD), electron mediator and CMC.
It could be found that the current response for glucose showed positive dependency on the concentration of CMC in the mix layer, at pH 7.0 of sample solution. While at pH 5.6, it was not that case. Main reason for this behavior was seemed to be chemical and/or physical interaction between GOD and CMC. A circular dichroism (CD) analysis suggestedthat structural change of GOD caused by pH condition was reduced significantly by contribution of CMC into the mix layer.

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7. ウレアーゼ/メルカプトヒドロキノン修飾電極によるボルタンメトリックな尿素の測定

水谷文雄、佐藤　縁、矢吹聡一

生命工学工業技術研究所

VOLTAMMETRIC DETERMINATION OF UREA WITH IMMOBILIZED UREASE/MERCAPTOHYDROQUINONE-COATED ELECTRODE

Fumio MIZUTANI, Yukari SATO and Soichi YABUKI

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

A voltammetric urea-sensing electrode was prepared by combining an urease layer with a mercaptohydroquinone-modified gold electrode. The addition of urea in a test solution (10 mM phosphate buffer, pH 7) brought about a decrease of pH near the electrode surface, which accompanied a positive shift of the anodic peak on the linear sweep voltammogram corresponding to the electro-oxidation of hydroquinone moiety on the electrode to form quinone. The concentration of urea (0.2-5 mM) could be determined by measuring the electrode current at -0.05 V vs. Ag/AgCl on the voltammogram for the urease/mercaptohydroquinone-based electrode. The electrode was applied to the determination of urea in human urine; the measurement of the electrode current at such a low potential provided the urea determination without any electrochemical interference from L-ascorbic acid and uric acid.

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8. 血中薬物濃度測定用化学センサの開発

勝　孝、森　幸

岡山大薬

ION-SELECTIVE ELECTRODES FOR MONITORING DRUGS IN BLOOD SERUM

Takashi KATSU and Yuki MORI

Faculty of Pharmaceutical Sciences, Okayama University
Tsushima, Okayama 700, Japan

Salicylate and disopyramide membrane electrodes were constructed and applied for the determination of salicylate and disopyramide in blood sera. This procedure is advantageous since the free concentrations of the drugs in sera can be deteimined without sample preparation. The free salicylate concentration determined by potentiometry using salicylate electrode compared with those obtained by conventional colorimetry gave a linear correlation coefficient of 0.997, while the free disopyramide concentrations determined by potentiometry compared with those obtained by florescence polarization immunoassay afforded a linear correlation coefficient of 0.996.

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特別講演 1. 絶縁性電解重合高分子膜を利用したバイオセンサの設計

逢坂　哲彌

早稲田大学理工学部

DESIGNING OF BIOSENSORS USING INSULATING ELECTROPOLYMERIZED FILM

Tetsuya OSAKA

Department of Applied Chemistry, School of Science and Engineering, WASEDA University
3-4-1 Okubo, Shinjuku, Tokyo 169, Japan

An insulating polypyrrole (PPy) film electrode, which is prepared by electropolymerization, displays Nernstian response well to pH. Such an electropolymerized film can be applied to potentiometric biosensor for urea enzyme reaction accompanying pH change. Urea sensors with three kinds of enzyme loading processes demonstrated different properties owing to the loading amount of enzyme. In particular, the urea sensor based on the composite film of insulating PPy and polyion complex shows high-sensitivity and high stability.

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9. SPR方式免疫センサの開発と基本特性（II）

市川幸子、外山　滋、山内　繁、碇山義人

国立リハビリ研

DEVELOPMENT AND CHARACTERIZATION OF SURFACE PLASMON RESONANCE(SPR) BASED IMMUMOSENSOR

Sachiko ICHIKAWA, Shigeru TOYAMA, Shigeru YAMAUCHI and Yoshihito IKARIYAMA

Research Institute, National Rehabilitation Center for the Disabled
4-1 Namiki, Tokorozawa 359, Japan

Realtime and nonlabelled sensing of immunoreaction has been investigated by a surface plasmon resonance(SPR)-based optical biosensor. Covalent binding of oxidized hydroxyethylstarch polymer was performed over thin gold film surface via self-assembled monolayer of aminoethanethiol. In this study, the immobilized starch layer was reduced by sodium borohydride after antigen immobilization, because Stiff's bases are not necessarily stable through the repeated dissociation by an acidic buffer, glycine-HCl (pH 2.5). By the NaBH₄ treatment of sensing chip the repeated detection of the determinant was performed at least 20 times.

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10. SPRセンサの高感度化のためのセンシング部位設計の最適化

外山　滋、市川幸子、碇山義人

国立リハビリ研

OPTIMIZATION OF SENSING FILM OF SPR DEVICE FOR INCREASING SENSITIVITY

Shigeru TOYAMA, Sachiko ICHIKAWA and Yoshihito IKARIYAMA

Research Institute, National Rehabilitation Center for the Disabled
4-1 Namiki, Tokorozawa 359, Japan

The sensitivity of immunosensors based on surface plasmon resonance (SPR) depends on not only the change in the minimum position (resonance angle) of reflected light intensity upon atigen-antibody binding but also the width and depth of trough around the resonance angle. These values can be predicted by calculating Fresnel's equation, when the thickness and the refractive indices of metal layers on prism are given. Here, we discuss the sensitivity of SPR devices based on various layer designs through the calculation of intensity profile of reflected light.

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11. 光ファイバを用いた濃度・吸着現象の測定

荻田正巳、吉村賢司、藤波達雄^*

静岡大工

MEASUREMENT OF CONCENTRATION AND ADSORPTION PHENOMENON USING OPTICAL FIBER

Masami OGITA, Kenji YOSHIMURA and Tatsuo FUJINAMI^*

Department of Electrical and Electronic Engineering, Faculty of Engineering, Shizuoka University
^* Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University
3-5-1 Johoku, Hamamatu 432, Japan

The structure of a surfactant molecule consists of two groups, hydrophilic and hydrophobic group. The possibility of detection of critical micelle concentration (CMC) is examined using optical fibers, POF and PCS, whose properties are hydrophobicity and hydrophilicity. The cladding is removed at the sensing region and the core is exposed to a sample solution. As the result, each output of POF and PCS increases drastically at CMC of 3×10^-3 (mol/l). The reason is that the reflectance increases as the surfactant molecules adsorb themselves on the surface of the sensing region.

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12. 電気化学発光免疫法による血清中 AFP の測定

薛　蒙得、春山哲也、小畠英理、相澤益男

東工大生命理工

ELECTROCHEMICAL LUMINESCENCE IMMUNOSENSOR FOR AFP

M. XUE, T. HARUYAMA, E. KOBATAKE and M.AIZAWA

Department of Bioengineering, Tokyo Institute of Technology
4259 Nagatsuka, Midori-ku, Yokohama 226, Japan

A homogeneous immunoassay for α-fetoprotein based on electrochemical luminescence was performed. Luminol labeled anti-AFP body was synthesized by diazo-coupling of luminol with antibody. While luminol-labeled antibody generated luminescence upon electrochemical oxidation, its luminescence decreased due to immunocomplexation. A standard curve of the present system indicated that the lower limit of AFP determination should be 1.0×10^-12 g ml^-1 in the time required 5 min. Using the present system, ECL-immunoassay in the human serum was also successfully performed.

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13. YbPc₂プラズマ重合膜を用いた湿度センサ

山名昌男、柏崎尚也

東京電機大

A HUMIDITY SENSOR USING YbPc₂ PLAZMA-POLYMERISED FILMS

Masao YAMANA and Naoya KASHIWAZAKI^*

Department of Natural Sciences, Tokyo Denki University
Haroyama-cho, Hiki-gun, Saitama 350-03, Japan
^* Department of Natural Sciences, Tokyo Denki University
2-1200, Bunseigakuendai, Innzai-si, Chiba 270-13, Japan

Humidity responses are compared between vacuum deposited and plasma-polymerised YbPc₂ films. The latter shows conductance increase with increaseing humidity, and furthermore high sensitivity and duarability at 28℃ of sensor temperature. The conductance increase for humidity is due to proton conduction.

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14. 容量型湿度センサ用高分子薄膜の評価　－水吸着特性－

松口正信、梅田　賢、定岡芳彦、酒井義郎

愛媛大工

CHARACTERIZATION OF POLYMER THIN FILMS FOR A CAPACITIVE-TYPE HUMIDITY SENSOR

Masanobu MATSUGUCHI, Ken UMEDA, Yoshihiko SADAOKA and Yoshiro SAKAI

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

Water sorption behavior in some less hydrophilic polymer was investigated for evaluating materials for a capacitive-type humidity sensor. Sorption analysis, IR measurment and novel solvatochromic technique were adopted for this purpose. The solvatochromic parameters particularly reflected the nature of a polymer and a state of adsorbed water. The present study shows that polymers, in which sorbed water doesn't form clusters, are suitable for a practical capacitive-type humidity sensor.

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15. 電池駆動微小熱線型半導体ガスセンサ II

小林博樹、丹上博雅、高田　義

新コスモス電機

MINIATURIZED HOT TYPE SEMICONDUCTOR GAS SENSOR OPERATED WITH A BATTERY II

Hiroki KOBAYASHI, Hiromasa TANJYOU and Tadashi TAKADA

New Cosmos Electric Co., Ltd.
2-5-4 Mitsuya-naka, Yodogawa-ku, Osaka 532, Japan

A group of miniaturized hot wire type semiconductor gas sensors with different gas selectivities, which was operated with a small battery, has been developed. For example, CH₄-selective and alkane-selective sensors were accomplished by forming a Pd catalyst thin layer on a sintered SnO₂ bead surface with electrodeposition method. H₂-selective sensor was also obtained by forming a SiO₂ thin layer on the bead surface with HMDS (hexamethyldisiloxane) treatment, and C₂H₅OH (odour)-selective sensor by modifying the sintered SnO₂ with addition of metal-oxides (Pb, La and Mo). These sensors have extremely low mean power consumption (below 600μW when operated with a temperature pulsing mode, namely 500℃ pulse of 200 msec duration applied every 20 sec) and show prompt gas response (within 200 msec), and this enables one to operate them with a small battery. Moreover, they showed the good long term stabilities. In the case of CH₄-selective sensor, more than 160 days have elapsed in this operation mode without any sensitivity-deterioration.

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16. ZnO-SnO₂薄膜を用いた酒類の鮮度センサ

南戸秀仁、森田　崇、小林俊起、羽原正秋、近藤浩一、山本　創、南　内嗣、筒口善央^*

金沢工大デバイス研、石川県工業試験場^*

FRESHNESS DETECTION OF ALCOHOL USING ZnO-SnO₂ THIN FILM SENSOR

Hidehito NANTO, Takashi MORITA, Toshiki KOBAYASHI, Masaaki HABARA, Kouichi KONDOU, Hajime YAMAMOTO, Tadatsugu MINAMI and Yoshiteru DOUGUCHI^*

Electron Device System Research Laboratory, Kanazawa Institute of Tech.
7-1 Oogigaoka, Nonoichi-machi, Ishikawa 921, Japan
^* Indust. Res. Institute of Ishikawa
1 Tomizu-machi, Kanazawa 920-02, Japan

The SnO₂ content dependence of the sensitivity of sputtered SnO₂-doped ZnO thin film chemical sensor is studied for various gases. It is found that the SnO₂(78 wt%)-doped ZnO thin film chemical sensor exhibits a high sensitivity and good selectivity for C₂H₅OH gas. The sensitivity of the SnO₂(78 wt%)-doped ZnO thin film chemical sensor responds to the freshness change of alcohols, indicating that the sensor is useful for freshness detection of alcohols.

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17. 一半導体素子を用いた新しいガス種の識別及びガス濃度の決定方法

高田　義、福永徹也

（新コスモス電機）

NEW METHOD FOR GAS IDENTIFICATION AND CONCENTRATION DETERMINATION -Simultaneous Measurement of Sensor Temperature and Semiconductor Resistance Changes

Tadashi TAKADA and Tetsuya FUKUNAGA

New Cosmos Electric Co., Ltd.
2-5-4 Mitsuya-naka, Yodogawa-ku, Osaka 532, Japan

Two reactions are important in considering reduced gases sensing characteristics of semiconductor gas sensors. One is the reaction between the reduced gases and surface oxygen (O^2-, O^-), which results in semiconductor resistance decrease, and the other reaction is the catalytic combustion on catalysts (exothermic reaction). The former reaction gives rise to a lower temperature shift of the sensor temperature, that is, it is pseud-endothermic. Therefore, in real semiconductor gas sensors, the pseud-endothermic and exothermic reactions always coexists with (or competes with) each other. It was frequently observed that the gas species causing a large (small) decrease in semiconductor resistance brought about only a small (large) increase in sensor temperature. In practical viewpoint, the above phenomena would enable one to identify the gas species and determine gas concentration with one semiconductor chip by making a map of (△R, △T). Each line on the map identifies the gas species. Gas species with any concentration is represented a point on the line characterized the species. If the line has no crossing with the other line, the species can be identified with (△Rm, △Tm), where m denotes a measured quantity, and the concentration of known gas can be easily determined from the gas concentration dependence curve.

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18. 焼結型酸化スズガスセンサの結晶成長過程

中川英元、土屋雅裕、作本弘司、朝倉祝治、福田健三、高橋祥夫^*、重盛徹志^*

横浜国大、新コスモス電機^*

EVOLUTION OF CRYSTALLINE STRUCTURES IN CALCINED TIN DIOXEDE GAS SENSING MATERIALS

Hidemoto NAKAGAWA, Masahiro TSUCHIYA, Koji SAKUMOTO, Sukuji ASAKURA, Kenzo FUKUDA, Sachio TAKAHASI^*, Tessi SHIGEMORI^*

Dept. of Mater. Sci. ＆ Chem. Eng.,Fac of Eng., Yokohama National University
^* New Cosmos Elctric Co. Ltd.

Crystalline structures of calcined tin dioxide are investigated. Pure and Ba-doped Ones are chosen as model gas sensing materials. It is shown that crystalline size increases with the increasing temperatures. The prime particles gather to form a secondary particle, but they are non-uniformly distributed and with small holes in it. The degree of non-uniformly and the size of the hole is larger in Ba-doped samples. It is conjectured that at high temperatures, small crystals coalesce to form a large crystal.

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19. 鉄系酸化物を用いた NO_xセンサ

齊藤弘喜、東　正志、野村良紀、川崎吉包

阪工大工

NO_x SENSOR USING IRON OXIDE

Hiroki SAITO, Masashi AZUMA, Ryoki NOMURA and Yoshikane KAWASAKI

Department of Applied Chemistry, Faculty Engineering, Osaka Institute of Technology
5-16-1 Ohmiya, Asahi-ku, Osaka 535, Japan

The gas sensing properties for NO_x (NO, NO₂) were investigated on α-Fe₂O₃ thick films doped with some transition metals (Mn, Co, Ni, Cu). It was found that the sensitivity to NO₂ gas on the Ni-doped α-Fe₂O₃ at 350℃ was more than 50 whereas that on the non-doped α-Fe₂O₃ was less than 2. Other dopants didn't show such drastic improvements on the sensitivity to NO₂. On the other hand, sensitivities to the NO gas were very small on these metal-doped and non-doped α-Fe₂O₃ thick films.

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20. 自動車室内の換気制御用２素子型センサ

大戸亀久美、河原裕美、真鍋太祐、野村　徹、松浦吉展、麻生　功

フィガロ技研

DUAL TYPE SENSOR FOR CONTROLLING VENTILATION OF CABIN IN MOTER VEHICLE

Kikumi OTO, Hiromi KAWAHARA, Taisuke MANABE, Tohru NOMURA, Yoshinobu MATSUURA and Isao ASO

Figaro Engineering Inc.
1-5-11 Senbanishi, Minoo-shi, Osaka 562, Japan

In order to drive a car comfortably, it is very important to intercept an inflow of harmful exhaust gas and to allow clean air to flow into the cabin. A dual type gas sensor was developed in order to control the ventilation of the cabin in motor vehicle. This sensor was equipped with two sensing materials, those were WO₃ and SnO₂. WO₃ showed excellent sensing characteristics to NO_x and was used to detect diesel exhaust gas. On the other hand, SnO₂ showed excellent sensing characteristics to combustible gases and was used to detect gasoline exhaust gas. The control system using this sensor was tested in actual running mode. It was confirmed that the system successfully detects the exhaust gases from not only diesel engine but also gasoline engine.

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21. 気孔の制御による酸化インジウム薄膜のガス検出特性の改善

前川　亨、高尾雄二^*、清水康博、江頭　誠

長崎大工、長崎大海洋^*

IMPROVEMENT OF GAS SENSING PROPERTIES OF In₂O₃ THIN FILMS BY POROSITY CONTROL

Toru MAEKAWA, Yuji TAKAO^*, Yasuhiro SHIMIZU and Makoto EGASHIRA

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

Gas sensing properties of In₂O₃ thin films have been investigated in conjunction with microstructure and porosity of the films. No clear relationship among gas sensitivities to NO₂ and O₃, particle size and film thickness was observed when In₂O₃ thin films prepared by thermal decomposition of acetylacetone indium were employed. In the case of porous In₂O₃ thin films prepared by firing the mixture of In₂O₃ particles and organic particles used as pore forming agent, gas sensitivities to NO₂, NO and O₃ tended to increase with an increase in porosity.

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22. 遷移金属酸化物を添加した In₂O₃系素子の CO 検知特性

山浦弘之、玉置　純、守屋浩二^*、三浦則雄、山添　曻

九大総合理工、大阪ガス^*

CO SENSING CHARACTERISTICS OF INDIUM-OXIDE-BASED ELEMENT LOADED WITH TRNSITION METAL OXIDE

Hiroyuki YAMAURA, Jun TAMAKI, Koji MORIYA, Norio MIURA and Noboru YAMAZOE

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

From a screening test of single oxides for their sensing properties, In₂O₃ was found to exhibit rather high sensitivity to CO as well as H₂ in wet air at 300℃. In order to improve the selectivity to CO over H₂, In₂O₃ was impregnated with various metal oxides. As a result, some of transition metal oxides were found to improve markedly both sensitivity and selectivity to CO. Particularly, Co₃O₄ (0.5 wt%)-In₂O₃ element showed quite high selectivity to CO, i.e., the sensitivity to CO was 7 times as high as that to H₂. The element could detect 500-4000 ppm CO in wet air at 250℃ satisfactorily.

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23. 安定化ジルコニアと酸化物電極を組み合わせた混成電位型ガスセンサ

来仙貴久、廬　革宇、三浦則雄、山添　曻

九大総合理工

MIXED-POTENTIAL-TYPE GAS SENSOR COMBINING STABILIZED ZIRCONIA WITH OXIDE ELECTRODE

Takahisa RAISEN, Geyu LU, Norio MIURA and Noboru YAMAZOE

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

A zirconia-based electrochemical device attached with an oxide electrode was developed for the detection of H₂ (or CO) in air. Among the oxides tested, ZnO was found to be best suited for the H₂ sensing electrode, giving sharp and selective response to 50-500 ppm H₂ in air at rather high temperature, such as 500 and 600℃. The H₂ sensing mechanism was confirmed to involve a mixed potential at the sensing oxide electrode, on the basis of the polarization measurements. For the CO detection, an Mn₂O₃-attached device was found to give selective response to CO over H₂ in the CO concentration range of 100-1000 ppm at such medium temperature as 300℃.

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24. 安定化ジルコニアディスクを用いた固体電解質センサの SO₂応答特性

武藤行弘、三浦則雄^*、山添　曻^*

福岡県工技セ、九大総合理工^*

SO₂ SENSING PROPERTIES OF SOLID-STATE ELECTROCHEMICAL SESOR USING DISC OF MgO-STABILIZED-ZIRCONIA

Yukihiro MUTO, Norio MIURA^* and Noboru YAMAZOE^*

Fukuoka Industrial Technology Center
332-1 Kamikoga, Chikushino-shi, Fukuoka 818, Japan
^* Department of Materials Science and Technology, Graduate Sciencs, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

Solid-state electrochemical SO₂ sensors were fabricated by using a disc of MgO stabilized zirconia (MSZ) and an auxiliary phase of Li₂SO₄-CaSO₄-SiO₂ (4:4:2 in molar ration). It was found that the amounts of MgO doped in MSZ influenced the morphology as well as Mg distribution of the surface of the MSZ discs obtained and then the EMF responses of the resulting devices. Among the various discs tested, the 15 mol% MgO doped one gave the best sensing characteristics to SO₂ in air at 600℃, following Nernst's equation for the 2-electron reduction of SO₂. Based on these results, the SO₂ sensing mechanism was briefly discussed.

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25. NH₄⁺を伝導種とする固体電解質型 NH₃センサの選択的ガス検出特性

今中信人、田村真治、足立吟也

阪大工

SELECTIVE AMMONIA SENSING CHARACTERISTICS OF SENSOR WITH NH₄⁺ ION CONDUCTING SOLID ELECTROLYTES

Nobuhito IMANAKA, Shinji TAMURA and Gin-ya ADACHI

Department of Applied Chemistry, Faculty of Engineering, Osaka University
2-1 yamadaoka, Suita, Osaka 565, Japan

An ammonia sensor was set up with combination of NH₄⁺-Ga₂O₃ and praseodymium ammonia sulfate applied as a solid electrolyte and a reference electrode, respectively. The sensor output was coincided with the relation derived from Nernst equation. Any interference with the coexistence of other gasses such as CO₂, NO, NO₂, and H₂O was not observed. The excellent performance in sensing ammonia was demonstrated not only with rapid and accurate response but also with high selectivity.

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26. 塩化バリウム系固体電解質を用いた塩素ガスセンサにおける酸化バリウムの影響

青野宏通、杉本榮佑、山林亜矢子、森　芳秋^*、定岡芳彦^**

新居浜高専、住友金属鉱山^*、愛媛大工^**

INFLUENCES OF BARIUM OXIDE CONTAMINATION FOR Cl₂ GAS SENSOR USING BaCl₂-KCl SOLID ELECTROLYTE

Hiromichi AONO, Eisuke SUGIMOTO, Ayako YAMABAYASHI, Yoshiaki MORI^*, and Yoshihiko SADAOKA^**

Department of Industrial Chemistry, Niihama National College of Technology
7-1 Yagumo-cho, Nihama, Ehime 792, Japan
^* Niihama Research Laboratory, Sumitomo Metal Mining Company, Limited
3-5-3, Nishibara-cho, Niihama, Ehime 792, Japan
^** Department of Materials Science and Engineering, Faculty Engineering, Ehime University
Matsuyama 790-7, Japan

The influences of BaO contamination on the behavior of a Cl₂ gas sensor using a 0.97BaCl₂-0.03KCl solid electrolyte were investigated. The addition of BaO to the electrolyte was found to produce unfavorable effects on both the measuring electrode and the reference through a side reaction. The presence of BaO in the vicinity of the measuring electrode result in decreases in the EMF and rate of response especially by lowering the Cl₂ gas concentration below a few tens ppm. Its presence near the barium oxides on the reference electrode, on the other hand, resulted in the upward deviation of the EMF over the entire range of Cl₂ concentration. The probe prepared in vacuo, free of such BaO contamination, gave EMFs in good agreement with the theoretical ones for Cl₂ gas concentrations between 10 ppm and 1000 ppm. In contrast, the probe prepared in air, showed a slower response and more extensive deviation to Cl₂ below 10 ppm, suggesting that the electrolyte near the measuring electrode was contaminated with BaO.

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27. 塩化鉛（II）系固体電解質を用いた常温型塩素ガスセンサ

新関良夫、柴田茂雄

東北工大

ORDINARY TEMPERATURE TYPE Cl₂ GAS SENSOR USING PbCl₂ SOLID ELECTROLYTE

Yoshio NIIZEKI and Shigeo SHIBATA

Faculty of Engineering, Tohoku Institute of Technology
Yagiyama Kasumi-cho, Taihaku-ku, Sendai 982, Japan

A new ordinary temperature type chlorine gas sensor of a galvanic cell type, Pb | PbCl₂ + 10 mol% K₂SO₄ + 10mol% Al₂O₃ | Cl₂ (x %), RuO₂, has been made. The sensing characteristics of the sensor followed Nernst's equation very well in the concentration range of 0.01 to 100 % of chlorine in air at ordinary temperature. The 90 % response times were less than ca. 10 sec for 0.1 to 100 % of the chlorine concentrations.

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28. Li₂O-SiO₂ガラス薄膜を用いた薄膜 CO₂センサ

進藤清孝、平井知子、望月重樹

三井石化

THIN FILM CO₂ SENSOR USING Li₂O-SiO₂ GLASS FILMS

Kiyotaka SHINDO, Tomoko HIRAI, Shigeki MOCHIZUKI

High Performance Materials And Products Research Laboratories, Mitsui Petrochemical Industries, Ltd.
Nagaura, Sodegaura-shi, Chiba 299-02, Japan

A thin film type CO₂ sensor using a Li₂O-SiO₂ glass film as a solid electrolyte layer and Li₂O₃ film as a sensing electrode layer was fabricated by RF-magnetron sputtering on a yttria-stabilized zirconia (YSZ) substrate. The electromotive force (EMF) of the sensor linearly depends on the logarithm of CO₂ concentration, following the Nernst's equation in the range of 200 ppm-1 % at 400℃ and 450℃. The 90 % response time was within 10 sec during increasing and decreasing CO₂ concentration.

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特別講演 2. 自動車用の新規な化学センサのニーズ

清田文夫

リケン

UP-COMING NEED FOR THE CHEMICAL SENSORS IN AUTOMOTIVE USE

Fumio KIYOTA

R&D Division, Riken Corporation

Predicted the up-coming need for the chemical sensors in point of the progress of automotive engines to cope with the environmental demands and the improvement of compartment amenity (air quality). NO_x sensor and HC sensor are suggested to be used for the applications of the engine combustion control, and the diagnosis of the emission clarification system. Also, an application of NO_x sensor to the compartment amenity control is considered.

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