Vol. 8, Supplement B (1992)

Digest of the 15th Chemical Sensor Symposium
September 24-25, 1992
Hokkaido University

Abstracts

1
高選択性薄膜CH4センサ

 大西久男・工藤周三・松本　毅・一本松正道

大阪ガス基盤研

THIN FILM CH4 SENSORS OF HIGH SELECTIVITY

Hisao OHNISHI, Shuzo KUDO, Takeshi MATSUMOTO and Masamichi IPPOMMATSU

Fundamental Research Laboratories, Osaka Gas Co., Ltd.
Konohana-ku, Osaka 554, Japan

We have developed high selectivity CH4 sensors based on SnO2 semiconductor thin films. The SnO2 thin films were deposited on sapphire substrate by the reactive RF magnetron sputtering method. And the gas selectivity was given by the laminating layer which have selective permeability of CH4 and the partial-oxidation activity of CH4. The selective permeability results from the selective-oxidation activity of H2, C2H5OH or CO.


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2
反応性RFスパッタ法による高感度ガスセンサ

 上野博信・松浦吉展・福岡　敦*・高橋夏樹*

フィガロ技研・東京ガスフロンティア研*

HIGH SENSITIVE GAS SENSOR USING RF REACTIVE SPUTTERING METHOD

 Hironobu UENO, Yoshinobu MATSUURA, Atsushi FUKUOKA* and Natsuki TAKAHASHI*

Figaro Engineering Inc.,
Minoo-shi, Osaka 562, Japan
*Frontier Technology Research Institute Tokyo Gas Co., Ltd.,
Tsurumi-ku, Yokohama 230, Japan

To improve sensitivity and selectivity to H2S, we have studied SnO2 thin film sensors prepared by RF reactive sputtering method. The influence of the preparation conditions such as film thickness, total pressure, oxygen partial pressure and calcination temperature on the sensitivity and the selectivity was clarified. The sensitivity and the selectivity to H2S were improved by decreasing the film thickness. As for the calcination temperature, the sensitivity and the selectivity increased with rising the temperature from 500℃ to 600℃. Furthermore, the sensitivity increased with increasing the total pressure or the oxygen partial pressure.


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3
ZnO系薄膜ガスセンサによるガス種の判別

 河合孝明・遠藤文孝・南戸秀仁

金沢工大デバイス研

GAS DISCRIMINATION USING ZINC OXIDE THIN FILM GAS SENSOR

 Takaaki KAWAI, Fumitaka ENDO and Hidehito NANTO

Electron Device System Research Laboratory, Kanazawa Institute of Technology
7-1 Oogigaoka, Nonoichimachi, P. O. Kanazawa-South, Ishikawa 921, Japan

Transient responses for exposure to gases such as trimethylamine (TMA), dimethylamine (DMA), hydrogen, aceton and ethanol are observed using sputtered zinc oxide (ZnO) thin film gas sensors. To disciminate among TMA, DMA and others, the pattern recognition analysis using neural network is carried out using parameters which characterize the transient responses. The recognition probability of neural network is about 90% and 75% for the discrimination using a constant amount of gases and different amount of gases, respectively.


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4
酸素雰囲気下で焼成したルチルの感湿特性

 友常茂宏・伊藤　滋・小浦延幸

東理大理工

HUMIDITY SENSITIVE CHARACTERISTICS OF RUTILE FIRED IN OXYGEN ATMOSPHERE

 Shigehiro TOMOTSUNE, Shigeru ITO and Nobuyuki KOURA

Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo
Noda-shi, Chiba 278, Japan

Rutile ceramics were prepared by firing at 800℃ for two hours under the atmosphere of oxygen. The impedance of the rutile, which was measured at 25℃ applying 50Hz of ac, decreased from 107.5 Ω to 105.5 Ω with an increase in relative humidity. The humidity sensitive characteristics of the rutile were comparable to that of 1 mol% V2O5 doped rutile. It seems that the addition of oxygen to rutile plays an important role in humidity sensitivity.


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5
チオラクトン環を有する色素―高分子複合膜を用いた光学的化学センサ（湿度およびアンモニアの検出）

 定岡芳彦・松口正信・酒井義郎・山田昌弘

愛媛大工

OPTOCHEMICAL SENSOR USING POLYMER COMPOSITE WITH DYE HAVING THIOLACTONE RING
-QUANTIFICATION OF HUMIDITY AND AMMONIA VAPOR-

 Yoshihiko SADAOKA, Masanobu MATSUGUCHI, Yoshiro SAKAI and Masahiro YAMADA

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

By using two types of dye-poly (methylmethacrylate) composite thin films, a optochemical sensor for quantification of humidity and ammonia was fabricated. The optical intensity at 475 nm for thymol blue composite was responsible to the humidity changes and was insensitive to the ammonia. The ammonia concentration could be determined from the optical intensity at 595 nm of bromocresol purple composite thin film and the determined humidity.


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受賞講演１
ガス分子認識のためのセラミックスの機能界面の設計と制御に関する研究

清水康博

長崎大工

CONTROL AND DESIGN OF INTERFACIAL PROPERTIES OF CERAMICS TO PROMOTE GAS-SENSING FUNCTIONS

 Yasuhiro SHIMIZU

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

This report reviews our latest studies aimed at promoting gas-sensing functions of ceramics. The objective gases to be dealt with here are water vapor, oxygen and trimethylamine. Preparation principles and methodology essential for creating high performance gas sensors are summarized. In addition to the reactivity of inflammable gases, emphasis is placed on the importance of controlling diffusion process of gases so as to create intelligent semiconductor gas sensors.


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受賞講演２
長寿命ガルバニ電池式酸素センサの開発と実用化

 藤田雄耕・工藤寿士・北村直也

日本電池

DEVELOPMENT OF LONG-LIFE GALVANIC-TYPE OXYGEN SENSOR AND ITS COMMERCIALIZATION

 Yuko FUJITA, Hisashi KUDO and Naoya KITAMURA

Japan Storage Battery Co., Ltd.,
Nshinosho Kisshoin, Minami-ku, Kyoto 601, Japan

A very long-life Galvanic-type oxygen sensor has been developed. The electrolyte of the sensor is weak acid buffer solution consisting 5 M/L AcOH-4 M/L AcOK-0.1 M/L (AcO)2 Pb (pH=6.1). The cathode is porous Au spattered on a surface of FEP membrane and the current collector of the cathode is carbon paper. This sensor has not only very stable out-put voltage, but also 10 to 20 times longer life than that of KOH electrolyte, and is not affected by acidic gas such as CO2 at all. The application of the sensor to a dissolved oxygen monitor is also described.


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受賞講演３
限界電流式ジルコニア酸素センサの開発

 佐治啓市・近藤春義・高橋英昭

豊田中研

DEVELOPMENT OF LIMITING CURRENT-TYPE ZIRCONIA OXYGEN SENSOR

 Keiichi SAJI, Haruyoshi KONDO and Hideaki TAKAHASHI

Toyota Central Research and Development Labs., Inc.
41-1 Yokomichi Nagakute Ngakute-cho, Aichi-gun, Aichi 480-11, Japan

For the past twenty years, social demands for improving fuel efficiency of automobiles, as well as for reducing pollutant exhaust emissions, have been increasing. In this situation, we have developed a limiting current-type zirconia oxygen sensor for lean combustion engines which aim at high fuel efficiency. Furthermore, the operation characteristics of the limiting current-type zirconia oxygen sensor was investigated. This investigation revealed that this sensor has the advantages of output linear to oxygen concentration, its weak temperature dependence and fast response, and the sensor proved suitable for controlling air-fuel ratio of the lean combustion engine. As the result, the oxygen sensor was put to practical use in 1984 and has been contributing to energy saving of automobiles.


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受賞講演４
限界電流式ジルコニア酸素センサの開発

中沢光博・浅田昭良

藤倉電線

DEVELOPMENT OF LIMITING CURRENT-TYPE ZIRCONIA OXYGEN SENSOR

 Mitsuhiro NAKAZAWA and Akiyoshi ASADA

Fujikura Ltd.
1-5-1 Kiba Koto-ku, Tokyo 135, Japan

A limiting current-type oxygen sensor using a zirconia solid electrolyte has been developed and used for various applications. The oxygen sensor has some excellent features such as no reference gas and a compact body compared to conventional ones. Recently, the sensor has been improved from the viewpoint of low temperature operation (low power consumption) and long term stability. In this sensor, a diffusion hole is placed in the zirconia electrolyte and a heater is attached on the top of the sensor cap. This sensor could realize the expected characteristics, without effecting the other properties. The basic properties including measurement principle and structure are introduced.


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6
水晶振動子ガスセンサとニューラルネットワークによる香りの判別

 河合孝明・村山和彦・南戸秀仁

金沢工大デバイス研

AROMA DISCRIMINATION USING A QUARTZ-RESONATOR GAS SENSOR IN CONJUNCTION WITH NEURAL NETWORK PATTERN RECOGNITION

 Takaaki KAWAI, Kazuhiro MURAYAMA and Hidehito NANTO

Electron Device System Research Laboratory, Kanazawa Institute of Technology
7-1 Oogigaoka Nonoichimachi, P. O. Kanazawa-south, Ishikawa 921, Japan

Transient responses for exposure to aromas which are generated by vaporizing different kinds of wine or dripped coffee on a heater are observed using quartz-resonator gas sensor which is coated with epoxy or vinyl-acetate resin. The pattern recognition analysis using neural network is carried out using parameters which characterize the transient response curves. The recognition probability of neural network is 80% and 90% for different kinds of aromas from wine and dripped coffee, respectively.


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7
ピエゾエレクトリックセンサ (1)イオン、バイオセンサへの応用

 丸山博文・本郷一隆・野上暁一

九工大工

PIEZOELECTRIC ION AND BIO SENSORS

 Hirofumi MARUYAMA, Kazutaka HONGO and Gyoichi NOGAMI

Department of Electrical Engineering, Kyushu Institute of Technology
Tobata-ku, Kitakyushu 804, Japan

Piezoelectric ion and bio sensors were developed. Piezoelectric material such as perovskite was deposited onto a metal substrate by Hydrothermal-Electrochemical method in an autoclave. The resultant electrode was paired with a counter electrode and immersed in solution. When an external step bias was applied, transient current was observed even in pure water, the electric conductivity of which was extremely small. The initial current was precisely proportional to the ionic concentration of the solution. A detection limit of the sensor depends on the purity of solvent. When extra pure water is used, its detection limit is about 10-7 M.
This sensor can be also used as a bio sensor. Since urea, for example, is converted to ammonium ion by enzime, its concentration can be easily measured.


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8
ピエゾエレクトリックセンサ (2)粘土、温度センサへの応用

 本郷一隆・丸山博文・野上暁一

九工大工

PIEZOELECTRIC VISCOSITY AND TEMPERATURE SENSORS

 Kazutaka HONGO, Hirofumi MARUYAMA and Gyoichi NOGAMI

Department of Electrical Engineering, Kyushu Institute of Technology
Tobata-ku, Kitakyushu 804, Japan

Piezoelectric viscosity and temperature sensors were fabricated by a piezoelectric sensor (BaTiO3 thin film electrode) shown in the preceding study. The initial current observed when an external step bias was applied decreased with increasing the viscosity of a solution. The initial current was precisely proportional to the reciprocal of kinematic viscosity which is defined as viscosity/density of a solution. Similarly, the initial current-temperature curves showed linearity. Since this sensor can monitor the information near the electrode, it can be used as a simple and sensitive sensor with the shortest response time.


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9
表面光電圧法を用いた集積化（味覚）センサ

 金井康通・内田秀和・清水正章・前川　仁・勝部昭明

埼玉大工

INTEGRATED SENSOR SYSTEM USING SURFACE PHOTOVOLTAGE TECHNIQUE

 Yasuyuki KANAI, Hidekazu UCHIDA, Masaaki SHIMIZU, Hitoshi MAEKAWA and Teruaki KATSUBE

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

A semiconductor ion sensor of integrated functions was developed by using a Surface Photo Voltage (SPV) Technique. The SPV method was successfully applied to the multiple sensors fabricated on a semiconductor that make it possible to measure surface potential without contact to each sensing site. Two dementional surface potential map, which was detected by sweeping the photon beam over the semiconductor surface, was used to identify the ion species in the electrolyte. The SPV method was also applied to immobilize the various kinds of ion sensitive membranes on a semiconductor surface combined with electrochemical polymerization method.


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10
固体電解質を用いたマイクロCOセンサの火災報知への応用

 渡部祥文・藤岡　透・山鹿範行・土井謙之・井上孝啓・幡井　崇・草薙繁量・佐藤晃由*・河関大祐*・細川直史*

松下電工中研・自治省消防庁消防研*

APPLICATION OF MICROELECTROCHEMICAL CO SENSOR USING SOLID ELECTROLYTE TO FIRE DETECTION

 Yoshifumi WATABE, Toru FUJIOKA, Noriyuki YAMAGA, Kenji DOI, Takahiro INOUE, Takashi HATAI, Shigekazu KUSANAGI, Kohyu SATOH, Daisuke KOUZEKI and Masafumi HOSOKAWA

Central Research Laboratory, Matsushita Electric Works. Ltd.
1048 Kadoma, Osaka, Japan
Fire Research Institute of Japan
3-14 Nakahara, Mitaka, Tokyo, Japan

The fundamental characteristics of microelectrochemical CO sensor were reported. In this paper, usefulness of CO sensor for fire detection was evaluated. The fire tests were conducted in a room simulated a guest room of a hotel. CO sensor, a photoelectronic smoke detector and a temperature sensor (C-C thermocouple) were attached on the ceiling in center of the room. Test fires were smoldering smoke, steam from a bath room and smoldering smoke from adjoining room. Consequently CO sensor detected smoldering smoke more rapid than the others and a smoke detector had a false alarm by steam but CO sensor didn't so.


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11
ガス濃淡電池式水素センサを用いた溶融アルミニウム中の水素濃度測定

 矢嶋　保・小出邦博・大島智子・武津典彦*・大橋昭男*・岩原弘育**

TYK 研・名工大工*・名大工**

MEASUREMENT OF HYDROGEN CONCENTRATION IN MOLTEN ALUMINUM ALLOYS USING GALVANIC CELL TYPE HYDROGEN SENSOR

 Tamotsu YAJIMA, Kunihiro KOIDE, Tomoko OSHIMA, Norihiko FUKATSU*, Teruo OHASHI* and Hiroyasu IWAHARA**

TYK Corporation, Research and Development Center
3-1 Ohbata-cho, Tajimi 507, Japan
*Department of Materials Science and Engineering, Nagoya Institute of Technology
Gokiso-cho, Showa-ku, Nagoya 466, Japan
**Synthetic Crystal Research Laboratory, School of Engineering, Nagoya University
Furo-cho Chikusa-ku, Nagoya 464-01, Japan

A galvanic cell type hydrogen sensor for molten aluminum alloys was developmed using CaZrO3-based proton conductor as a solid electrolyte in order to carry out the measurement of hydrogen concentration. This sensor stably worked in molten aluminum alloys and exhibited stable electromotive force corresponding to hydrogen concentration in molten metals. The hydrogen contents determined by this sensor was identified with the values by the other methods.


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12
リチウムイオン伝導体を用いた一端封止型炭酸ガスセンサ

 村田年秀・今中信人・足立吟也

阪大工

SINGLE SURFACE SEALED TYPE CARBON DIOXIDE GAS SENSOR BASED ON A LITHIUM IONIC CONDUCTOR

 Toshihide MURATA, Nobuhito IMANAKA and Gin-ya ADACHI

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

A carbon dioxide gas sensor was fabricated by combining a lithium conducting solid electrolyte of LiTi2(PO4)3+0.2Li3PO4 and an oxygen ionic conductor of (Bi2O3)0.75(Y2O3)0.25. One surface of the lithium conducting electrolyte was exposed to the ambient atmosphere, the other surface was sealed with the oxygen ionic conductor. The electromotive force obtained from the CO2 sensor at 650℃ coincided well with the Nernst equation. The variation of the partial pressure of oxygen in the atmosphere did not interfere with the sensor output. The single surface sealed type CO2 sensor demonstrated the ability to detect the CO2 gas continuously, accurately with a fast response under various oxygen contents.


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13
固体電解質(NASICON)を用いたNOxセンサの応答機構

 姚　勝・清水陽一・三浦則雄・山添　昇

九大総合理工

SENSING MECHANISM OF SOLID ELECTROLYTE NOX SENSOR

 Sheng YAO, Youichi SHIMIZU, Norio MIURA and Noboru YAMAZOE

Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

The solid electrolyte sensor device using a sodium ion conductor and NaNO3 or NaNO2 (auxiliary phase) was found to exhibit a remarkable feature that its EMF response to NO2 is totally independent of the concentration of coexistent oxygen. In the absence of NOx, the sensor EMF varied logarithmically with oxygen concentration, following the Nernst's equation for a 2-electron reaction of O2. Based on the results obtained, the sensing mechanism of solid electrolyte NOx sensor is proposed.


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14
ディスポーザブル乳酸センサの開発（第１報）

 吉岡俊彦・南海史朗

松下電器生活システム研

DEVELOPMENT OF DISPOSABLE LACTATE SENSOR (REPORT 1)

Toshihiko YOSHIOKA and Shiro NANKAI

Matsuhita Electric Industrial Co., Ltd.
Living Systems Research Center
3-1-1 Yagumo-nakamachi Moriguchi-shi, Osaka 570, Japan

A disposable lactate sensor, constructed from a carbon electrode and a reaction layer containing potassium ferricyanide as an electron mediator, lactate oxidase and a hydrophilic polymer, was investigated.
A L-lactate concentration could be measured up to ca. 160 mg/dl in 60 seconds and to 65 mg/dl in 25 seconds without dillution of a sample or stirring. Coefficients of variation were less than 3% for samples of L-lactate concentrations in the range of 24 to 105 mg/dl, and the sensor was considered to have a sufficient reproducibility. It was also confirmed that the initial response characteristics were retained for 30 days at 40℃ in dry condition.


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15
GOD/脂質コンプレックスを利用した迅速応答性グルコースセンサ

 水谷文雄・矢吹聡一・曽良達生

繊高研

AMPEROMETRIC SENSOR WITH FAST RESPONSE TO GLUCOSE BASED ON A GOD/LIPID-COMPLEX

 Fumio MIZUTANI, Soichi YABUKI and Tatsuo KATSURA

Research Institute for Polymers and Textiles
1-1-4 Higashi Tsukuba, Ibaraki 305, Japan

An amperometric enzyme electrode for glucose was prepared by using a lipid-modified glucose oxidase: a glassy-carbon electrode was first dipped into a benzene solution of the modified enzyme and then dried, and second, a Nafion coating was applied by dip-coating the electrode in a solution of the ionomer. The water-insoluble, modified enzyme was thus attached on the electrode surface with a strongly-adhered, thin Nafion overcoat. The anodic current (0.9 V vs. Ag/AgCl) increased immediately after the addition of glucose and the response time was lower than 2 s. A linear response to glucose was obtained up to 3 mM with a detection limit of 0.2 uM. The enzyme electrode could be used for more than a month.


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16
EEEセンサによる血糖値測定

 山内　繁・矢尾板仁・宇佐見将太*・碇山義人**

国立リハ研・埼玉工大*・東工大工**

GLUCOSE MEASUREMENT WITH ENZYME EMBODIED ELECTRODE (EEE) SENSOR IN WHOLE SERUM

 Shigeru YAMAUCHI, Masashi YAOITA, Shyouta USAMI* and Yoshihito IKARIYAMA**

Research Institute of National Rehabilitation Center for the Disabled
Tokorozawa, Saitama 359, Japan
*Dept. of Environmental Engineering, Saitama Institute of Technology
Okabe, Saitama 369-02, Japan
**Dept. of Bioengineering, tokyo Institute of Technology
O-okayama, Tokyo 152, Japan

When an enzyme embodied electrode for glucose measurement is used for a long period in whole serum its sensitivity decreases. This is mainly caused by coagulating protein at the platinum black surface. In order to overcome this difficulty surface of EEE sensor was coated with a Nafion film. Moreover, potentiostatic pulses of 0.5 V were employed, whereas pulses of 0.6 V are normally applied. In this condition a response current at 40 ms with the Nafion coated sensor for glucose was 2.25 and 2.19 μA in a serum containing 4.9 mM glucose and in phosphate buffered solution 5 mM glucose, respectively. From these results, we conclude that the pulse technique with the Nafion coated EEE sensor can be clinically used for whole serum without dilution.


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17
PREPARATION OF A MULTIFUNCTIONAL BIOCOMPATIBLE MEMBRANE AND ITS APPLICATION TO FABRICATE A NEEDLE-TYPE GLUCOSE SENSOR

 Chien-Yuan CHEN*,**, Eiichi TAMIYA*, Kazuhiko ISHIHARA***, Yuan-Chi SU**, Nobuo NAKABAYASHI***, Isao KARUBE*

*Research Center for Advanced Science and Technology, University of Tokyo
4-6-1 Komaba Meguro-ku, Tokyo 153, Japan
**Department of Agricultural Chemistry, National Taiwan University
1, Sec. 4, Roosevelt Rd., Taipei, Taiwan, R. O. C.
***Institute for Medical and Dental Engineering, Tokyo Medical and Dental University
2-3-10 Kanda-Surugadai Chiyoda-ku, Tokyo 101, Japan

A multifunctional membrane, MAC, with biocompatibility, diffusion-limiting effect and the ability to curtail the responses of a H2O2 electrode to ascorbate and urate was prepared. It was composed of MB, AB and CTA, where MB is the copolymer of 2-methacryloyloxyethyl phosphorylcholine (MPC) and n-butylmethacrylate (BMA); AB is the copolymer of acrylamide-2-methylpropane sulfonic acid (AMPS) and BMA; CTA is cellulose triacetate. The membrane was coated onto the working electrode of a needle-type glucose sensor on which immobilized glucose oxidase membrane has already been coated. The sensor did not respond to ascorbate and urate at their concentrations normally encountered in blood. It exhibited superior thermostability in addition to a rapid response (<90 sec. In batch operation), good reproducibility (RE<5%), good stability (more than 36 hours continuously in glycolyzed heparinized whole blood) and a wide dynamic range (5-600 mg/dl glucose). It was used to determine glucose in serum. The data obtained from the sensor showed good agreement with that from a clinical autoanalyzer (R= 0.973).


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18
GOD/POD/PPy膜電極における膜の導電性と感度の相関

 渡辺　毅・立間　徹・權平正幸・渡辺　正

東大生研

CORRELATION BETWEEN THE SENSITIVITY AND FILM CONDUCTIVITY FOR GOD/POD/PPy FILM ELECTRODES

 Tsuyoshi WATANABE, Tetsu TATSUMA, Masayuki GONDAIRA and Tadashi WATANABE

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

An amperometric glucose sensor was fabricated by controlled-current electropolymerization of pyrrole in the presence of glucose oxidase, peroxidase, and KCl. The electrode thus obtained responds to glucose cathodecally at +150 m V vs. Ag/AgCl or anodically at +700 mV. Polypyrrole is overoxidized and loses its conductivity at +700 mV so that the sensor sensitivity is lower than that at +150 mV, where polypyrrole is still conducting. The dependence of the sensor sensitivity on the film thickness is also examined.


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19
フェロセンを標識剤に用いたホモジニアス電気化学免疫測定

 碇山義人・小畠英理・須沢敏行・篠原寛明・相澤益男

東工大生命理工

A NEW ELECTROCHEMICAL IMMUNOASSAY OF HOMOGENEOUS FORMAT BASED ON THE REGENERATION OF FERROCENE LABEL

 Yoshihito IKARIYAMA, Eiry KOBATAKE, Toshiyuki SUZAWA, Hiroaki SHINOHARA and Masuo AIZAWA

Department of Bioengineering, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology
Nagatsuta Midori-ku, Yokohama 227, Japan

A new principle of electrochemical immunoassay with homogeneous format is proposed by employing ferrocene, hapten-conjugated proteins. The ferrocene label is undergone regeneration by coupling electrochemical oxidation and enzymatic reduction in the presence of glucose oxidase. The electroactive proteins, after immunoreaction with anti-digoxin antibody, become less accessable to electrode surface depending on the antibody concentration. Here, the authors would like to elucidate the proposed amplification technique for the development of a new homogeneous immunassay.


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20
食品鮮度の直接測定用センサ

 矢野幸男・横山憲二*・民谷栄一*・軽部征夫*

伊藤ハム中研・東大先端研*

DIRECT SENSING SYSTEM FOR MEAT FRESHNESS

 Yukio YANO, Kenji YOKOYAMA*, Eiichi TAMIYA* and Isao KARUBE*

Central research Institute, ITOHAM FOODS INC.
Moriya-machi Kitasouma-gun, Ibaraki 302-01, Japan
*Research Center for Advanced Science and Technology, University of Tolyo
Komaba Meguro-ku, Tokyo 153, Japan

A direct sensing system for monitoring meat freshness was developed. The sensor was composed of an Ag/AgCl electrode and a platinum electrode on which putrescine oxidase and xanthine oxidase were immobilized for putrefaction and aging, respectively. Potential-step method from 300 mV to 600 mV was applied to the measurement of substrates. These sensors showed good substrate specificity and pH specificity for direct sensing of meat. The putrescine sensor was applied to direct measurement of meat and was proved to be useful for non-destructive evaluation of bacterial putrefaction.


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21
A NOVEL BOD SENSOR BASED ON BACTERIAL LUMINESCENCE.

 C-K HYUN, K. NAKANISHI, K. YOKOYAMA, E. TAMIYA, I.KARUBE

Research Center for Advanced Science and Technology, The University of Tokyo
4-6-1 Komaba Meguro-ku, Tokyo 153, Japan

A reagent type BOD sensor with a new principle employing a luminous bacterium, Photobacterium phosphoreum, was developed. The increased intensity of luminescence resulting from the cellular assimilation of organic compounds in waste water was detected by a photodiode. The BOD response of the bacterial reagent could be obtained within 15 min. The temperature condition for optimal BOD response was 18-25℃ at pH 7-8, indicating that it is possible to measure BOD at room temperature without stabilizing the temperature of the measuring system. In comparison with conventional the 5-day BOD measurement for some waste water samples, BOD values estimated by the sensor showed a good agreement with those measured by 5-day method.


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特別講演１
膜蛋白質を用いる新しいバイオセンサの展開

 梅澤喜夫・菅原正雄

東大理・北大理

NEW APPROACHES FOR BIOSENSORS BASED ON MEMBRANE PROTEINS

 Yoshio UMEZAWA and Masao SUGAWARA

Department of Chemistry, Faculty of Science, The University of Tokyo
Hongo, Tokyo 113, Japan
Department of Chemistry, Faculty of Science, Hokkaido University
Sapporo 060, Japan

The potential use of membrane proteins Na+/D-glucose contransporter and Na+, K+-ATPase is described as the sensory elements for a new type of sensing system.


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22
螢光測定による抗真菌活性評価法の開発

 本間知夫・梁馨哲・松岡英明・根本泰行・澄田修生*・高鳥浩介**・倉田　浩***

東農工大工・バイオ技研*・食品薬品安全センター**・東京顕微鏡院***

DEVELOPMENT OF ANTIFUNGAL ACTIVITY EVALUATION METHOD BASED ON FLUORESCENCE MEASUREMENT

 Tomoo HOMMA, Hyeong Cheol YANG, Hideaki MATSUOKA, Yasuyuki NEMOTO, Osao SUMITA*, Kosuke TAKATORI** and Hiroshi KURATA***

Dept. Biotechnology, Tokyo Univ. Agricul. Technol.,
2-24-16 Nakamachi Koganei, Tokyo 184, Japan
*Research & Development Division, Bio-Giken Inc.,
1-5-8 Iwamotocho Chiyodaku, Tokyo 101, Japan
**Hatano Res. Inst., Food & Drug Safety Center,
729-5 Ochiai Hadano, Kanagawa 257, Japan
***The Tokyo Kembikyoin Foundation
4-8-32 Kudanminami Chiyodaku, Tokyo 101, Japan

Congo red (CR) showed an intense fluorescence at 614 nm when reacted with Aspergillus niger. This spectrum was assigned to the specific binding of CR with chitin. The fluorescence intensity (FI) at a fixed area (5 μm × 5μm) about 50 μm apart from the growing tip of a hypha was measured with a fluorescence microscopic image analyzing system. FI increased gradually and this increase suggested the increase in the CR binding site density (chitin or microfibril of chitin). On the other hand, FI at the growing tip was constant when the growing rate was constant (4 μm・min-1). When the growth was inhibited by N2 gas, FI increased immediately. Even after replacement of N2 gas by air, the growth rate further decreased and reached zero. About 4 min later, the growth rate began to increase again. FI changed in accordance with the growth rate change. In conclusion, the growth rate of a single hypha can be evaluated with use of CR.


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23
CCD素子を用いた大腸菌コロニーの連続観察

 宮本重幸・大橋昭王・木村　純・赤池敏宏*

日本電気資源研・東工大生命理工*

CONTINUOUS OBSERVATION OF E. Coli COLONY FORMATION USING A CCD

 Shigeyuki MIYAMOTO, Akio OHASHI, Jun KIMURA and Toshihiro AKAIKE*

Resources & Environment Protection Research Laboratories, NEC Corporation
Kawasaki, Kanagawa 216, Japan
*Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology
Yokohama, Kanagawa 227, Japan

A direct sensing equipment is improved to reduce heat from a CCD, and continuous long-term observation of E. coli propagation is accomplished by the equipment. A CCD, a video recorder and an LED, which construct the equipment, are periodically controlled by a personal computer. Possibility of continuous long-term observation is suggested when a control period is set up to four minutes. As a result of E. coli propagation observation, 70-hour continyous observation is achieved with no heat influence from the equipment.


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24
バイオサーモチップの開発

 下吹越光秀・中山千秋・横山憲二*・民谷栄一*・軽部征夫*

東陶機器・東大先端研*

DEVELOPMENT OF BIO-THERMOCHIP

 Mitsuhide SHIMOHIGOSHI, Chiaki NAKAYAMA, Kenji YOKOYAMA*, Eiichi TAMIYA* and Isao KARUBE*

Research & Development Division, TOTO LTD.,
Chigasaki, Kanagawa 253, Japan
*Research Center for Advanced Science and Technology, University of Tokyo
Meguro-ku, Tokyo 153, Japan

A new enzyme thermistor chip system was examined without using a highly temperature controlled thermostat. The heat capacity of this chip thermistor is very small and glucose oxidase is immobilized directly on the surface of the thermistor. The temperature difference between the enzyme immobilized thermistor and the reference thermistor were measured in the heat insulated cell. A linear calibration curve was obtained in the range from 1 mM to 5 mM. The dynamic range must be enhanced to put this system to practical use.


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