Vol. 11, Supplement A (1995)

Proceedings of the 20nd Chemical Sensor Symposium
April 3-4, 1995
The University of Tokyo

Abstracts


1.
Au, Fe ƒCƒIƒ“’“ü‚µ‚½ SnO2–Œ‚̃KƒXƒZƒ“ƒT[“Á«

–쑺‹M”üA‰–àV_–¾A‚“c@‹`AH. ƒƒCƒ^[

“ŒH‘åAVƒRƒXƒ‚ƒX“d‹@Aƒ[ƒ[ƒ“ƒhƒ‹ƒtŒ¤

GAS SENSOR PROPERTIES OF SnO2 FILMS IMPLANTED WITH Au AND Fe IONS

Kiyoshi NOMURA*1, Hiroaki SHIOZAWA*2, Tadashi TAKADA*2 and Helfried REUTHER*3

*1 Faculty of Engineering, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan
*2 New Cosmos Electric Co. Ltd.
2-5-4 Mitsuya-naka, Yodogawa-ku, Osaka-shi 532, Japan
*3 Forshungszentrum Rossendorfe, V. Institut fur Inonenstrahlphysik und Materialforschung
D-01314 Dresden, Germany

Gas sensor properties on SnO2 films are strongly dependent on the film preparation methods.@SnO2 films with 500 nm thickness were implanted with 40 keV Au and Fe ions. The implanted ions were located in the top 100 nm layers. Changes of gas sensitivity and morphology by Au and Fe ion implantions were investigated. The sensitivity to H2 and CO gas increased and the sensitivity to ethanol decreased relatively. However, thin SnO2 films with 100 nm thickness, implanted with Au and Fe ions, did not show sensitivity against any gas. Redox reaction in inner layers of thick SnO2 films was considered to contribute to the increase of selectivity of H2 gas.

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2.
ƒGƒsƒ^ƒLƒVƒƒƒ‹¬’·‚µ‚½ SnO2”––Œ‚Ìì»

¼“ˆ–ÎŒ›A–x@—z‰îA¬—ÑŒ’‹g˜YA‰ª“cŒ³ŽŸ

ˆ¤•Q‘åH

EPITAXIAL GROWTH OF SnO2 THIN FILMS

Shigenori MATSUSHIMA, Yousuke HORI, Kenkichiro KOBAYASHI and Genji OKADA

Department of Applied Chemistry, Faculty of Engineering, Ehime University
3-Bunkyo-cho, Matsuyama-shi 790, Japan

Tin oxide films have been prepared on single crystalline TiO2 (110) substrates by RF magnetron sputtering method. There was only the (110) reflection perk of SnO2 besides the (110) reflection of the TiO2 substrate. From rocking curve measurements, it was confirmed that a value of full width of half maximum (FWHM) of the rocking curve for SnO2 (110) reflection was 1.27 deg, which was comparable to that of TiO2 single crystal. A value of FWHM remained unchanged even after the sputtered films were annealed at 600Ž in air. Results of XPS measurements showed that binding energies (Sn3d5/2 and O1s) and O/Sn ratio of an as-deposited film were identical with those of SnO2, and that these values were not almost changed after calcination at 600Ž in air.

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3.
ƒ]ƒ‹‚æ‚è’²»‚µ‚½Ž_‰»ƒXƒY”––Œ‚Ì”÷×\‘¢‚Æ—°‰»…‘fŒŸ’m“Á«

™`@“sà\A‹Ê’u@ƒA–p@‡Žq*AŽO‰Y‘¥—YAŽR“Y@úf

‹ã‘呇—HAƒ\ƒEƒ‹‘åH–

MICROSTRUCTURE AND H2S SENSING PROPERTIES OF SnO2 THIN FILM PREPARED FROM SOL SOLUTION

Do Joon YOO, Jun TAMAKI, Soon Ja PARK*, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan
* Department of Inorganic Materials Engineering, College of Engineering, Seoul National University
Kawanak-ku, Seoul 151-742, Korea

The grain size of SnO2 (D) in the thin films prepared from sol solution decreased with decreasing film thickness when calcined at elevated temperature (800Ž) and D was kept to only ca. 6 nm in the thin film with 25 nm thick. Because of this notable phenomenon, the resistivity and H2S sensitivity of the films showed rather complex dependence on film thickness and calcination temperature. These characteristics could be reduced into either of two simple functions of D, depending on whether calcination temperature was lower (400 and 600 Ž) or higher (800Ž).

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4.
SnO2ÄŒ‹‘Ì‚ð—p‚¢‚½ NH3‘I‘ð«ƒZƒ“ƒT[ II |Ž¼“xˆË‘¶«‚̉ü‘P

‚“c@‹`A’O㔎‰ë

VƒRƒXƒ‚ƒX“d‹@

NH3 SELECTIVE GAS SENSOR USING SINTERED SnO2 - IMPROVEMENT OF ABSOLUTE-HUMIDITY DEPENDENCE OF THE SENSOR

Tadashi TAKADA and Hiromasa TANJOU

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

Absolute humidity dependence of NH3 selective sensor (Pd added-SnO2), in which Pd catalyst was distributed at high concentration on the sensor surface and at low concentration in the inner part of the sensor was improved by addition of metal-oxide, that is, Pb-oxide, La-oxide and so on, to SnO2 support on the sensor surface before Pd catalyst was distributed on the surface.

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5.
ZnO-SnO2 ”––ŒƒKƒXƒZƒ“ƒT‘fŽq‚̃KƒXŒŸ’m“Á«

“ìŒËGmAX“c@’A‰HŒ´³HA’Ö–ìŽj˜NA“ì@“àŽkA“›Œû‘P‰›*

‹à‘òH‘åƒfƒoƒCƒXŒ¤AÎ쌧H‹ÆŽŽŒ±ê*

GAS SENSING CHARACTERISTICS OF ZnO-SnO2 THIN FILM SENSORS

Hidehito NANTO, Takashi MORITA, Masaaki HABARA, Shiro TSUBAKINO, Tadatsugu MINAMI and Yoshiteru DOUGUCHI*

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

Gas sensing characteristics of sensors using zinc oxide thin films doped with SnO2 (ZnO-SnO2) were studied for exposure to various gases such as C2H5OH, CH3OH, CH3COCH3, (CH3)3N, CO, H2, C2H4, C3H8 and ((CH3)2CHCH2COOH). It was found that a sensor using ZnO-SnO2(78wt%) thin film exhibited a high sensitivity for exposure to C2H5OH gas.

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6.
WO3ŒnƒAƒ“ƒ‚ƒjƒAƒZƒ“ƒT

‘ºŽR‰p”üA¼‰Y‹g“W

ƒtƒBƒKƒ‹ZŒ¤

Ru-LOADED WO3 AMMONIA SENSOR

Hidemi MURAYAMA and Yoshinobu MATSUURA

FIGARO ENGINEERING INC.
1-5-3 Senbanishi, Minoo City, Osaka 562, Japan

Several kinds of sensing materials and dopants were examined for an ammonia sensor, and as a result, Ru-loaded WO3 was found to be very effective. The sensitivity to ammonia depended on the amount of loaded Ru and had the maximum value at 0.022 wt% to WO3. This sensor showed more superior characteristics in sensitivity, response, and selectivity than the ones of conventional SnO2 sensor.

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7.
RF ƒvƒ‰ƒYƒ} CVD ‚É‚æ‚è컂µ‚½ In2O3”––Œ‚̃KƒXŒŸo“Á«

‚”ö—Y“ñA–Ô“c_ˆêA´…N”ŽA]“ª@½

’·è‘åH

GAS-SENSING PROPERTIES OF In2O3 THIN FILMS PREPARED BY RF-PLASMA ASSISTED CHEMICAL VAPOR DEPOSITION

Yuji TAKAO, Kouichi AMITA, Yasuhiro SHIMIZU and Makoto EGASHIRA

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

Variations in H2, NO2 and O3 sensitivities with sensor thickness have been investigated by employing In2O3 thin films fabricated by RF-plasma assisted chemical vapor deposition. The sensitivities of a thermal decomposition film and spin-coating films were also studied as a function of their thickness. H2 sensitivity was found to be independent of the sensor thickness, but it was suggested that the resistance of films was more important factor than their thickness in the thickness range of the sensor tested. In the case of the oxidizing gases, the NO2 and O3 sensitivities increased with an increase in the sensor thickness up to 0.3ƒÊm and beyond that the sensitivities remained almost constant at 300Ž.

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8.
Ž_‰»•¨”¼“±‘Ì‚ð—p‚¢‚½”RÄ”rƒKƒX—p CO ƒZƒ“ƒT

ŽR‰YO”VA‹Ê’u@ƒAŽO‰Y‘¥—YAŽR“Y@úf

‹ã‘呇—H

OXIDE SEMICONDUCTOR GAS SENSOR FOR CO IN COMBUSTION EXHAUSTS

Hiroyuki YAMAURA, Jun TAMAKI, Norio MIURA and Noboru YAMAZOE

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

From a screening test of 26 single oxides for their sensing properties, In2O3 were found to exhibit rather high sensitivity to both CO and H2 in wet air at 300Ž. In order to improve the selectivity to CO against H2, In2O3 was added (5wt%) with each of 33 metal oxides. As a result, the addition of alkaline metal oxides was found to improve markedly both sensitivity and selectivity to CO. Particularly, Rb2O (5wt%)-In2O3 showed the highest CO selectivity, i.e., sensitivity to CO was about 9 times as high as that to H2. It could detect 500-4000 ppm CO in air at 300Ž satisfactorily.

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“Á•Êu‰‰ 1.
‚•ªŽqÞ—¿‚ւ̃KƒX‹z’…‚ƃZƒ“ƒT‚ւ̉ž—p

Žðˆä‹`˜Y

ˆ¤•Q‘åH

SORPTION OF GAS IN POLYMERIC MATERIALS AND IT'S APPLICATION TO SENSORS

Yoshiro SAKAI

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

Several equations have been proposed for the sorption of gases in polymers. The model of sorption depends on the phase of the polymer, that is, whether the polymer is in glassy state or rubbery state. It also depends on the affinity between the gas and the polymer. The dual mode sorption model (Henry type plus Langmuir type) proposed by Barrer et al. was applied to the sorption of acetic acid vapor in the copolymer of N,N-dimethylaminoethyl methacrylate (DMAEM) and methyl methacrylate (MMA). The sorption parameters of the dual mode equation were estimated from the data obtained by the quartz crystal microbalance method. It was found that the fraction of Henry type sorption is smaller as the mole fraction of DMAEM in the copolymer is smaller.

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ŽóÜu‰‰ 1.
”¼“±‘̃KƒXƒZƒ“ƒT‚Ì‘gD§Œä‚ƃjƒIƒCE‘N“x‘ª’è‚ւ̉ž—p

]“ª@½

’·è‘åH

FUNCTIONAL DESIGN OF SEMICONDUCTOR GAS SENSORS FOR ODORS/FRESHNESS MEASUREMENT

Makoto EGASHIRA

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 realizing semiconductor odor sensors: these include the temperature programmed desorption study of oxygen adsorbates, the gas sensing properties of oxide whiskers, control of gas permeability and reactivity in the porous sensing layer, and the gas response of the current-voltage characteristics of varistor-type sensors. Based on these fundamental approaches, sensors for trimethylamine, dimethylamine and ammonia have been developed to be applied to fish freshness detection.

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9.
Šó“y—Þ|“º‚Ì•¡‡Ž_‰»•¨‚ð—p‚¢‚½ NOxƒZƒ“ƒT

œA“c—m•½A¡’†MlA‘«—§‹á–ç

ã‘åH

NOx SENSOR WITH RARE EARTH-COPPER OXIDES

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 NOx (NO, NO2) sensing characteristics of rare earth copper oxides, Ln2Cu2O5 (Ln=Y, Dy, Yb etc.), were investigated. The electrical resistivity of the Dy2Cu2O5 oxide bulk decreased with the increase of the NO2 concentration at the temperatures below 600Ž. At 600Ž, the oxide showed such a peculiar characteristics to respond only to NO2 in NOx existing atmosphere. The response time to NO2 was within 10 min., which was faster than that of Yb2Cu2O5 and Y2Cu2O5 bulk.

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10.
ƒyƒƒuƒXƒJƒCƒgŒ^•¡‡Ž_‰»•¨‚ð—p‚¢‚½ NOxƒZƒ“ƒT

ŒIŒ´‹ÅA“c’†LˆêA™ŽR˜a•v

é‹Ê‘åH

NOx SENSOR USING PEROVSKITE-TYPE OXIDES

Yoshiaki KURIHARA, Shinichi TANAKA and Kazuo SUGIYAMA

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

NOx (NO, NO2) sensing properties of various perovskite-type oxide (ABO3: A=La3+, Nd3+, Sm3+; B=Cr3+, Mn3+, Fe3+, Co3+) thick films have been investigated in a stream of synthetic air at the temperature range of 300-550Ž. A superior ability to sense NOx, especially NO2 was observed in the use of perovskite samples consisting of a B site ion made up of Fe3+ ion. A SmFeO3 sample was the most sensitive to NO2 molecules at the optimum temperature of 500Ž and showed a linear sensitivity to the NO2 concentration in a range of 250-3000 ppm.

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11.
ƒ}ƒ‹ƒ`ƒZƒ“ƒT‚ÌŽº“à‹ó‹C‰˜õ•¨‚ɑ΂·‚éo—Í“Á«

‘å–÷‘½‰ÂŽuAÕ@šõçAÎ⺎OA–Ø‘ºt•F*A¼‰Y‹g“W**AŠŽR—T‹v**

•xŽR‘Û‘åŠwl•¶A‹à‘ò‘åH*AƒtƒBƒKƒ‹ZŒ¤**

OUTPUTS OF FIVE GAS-SENSORS FOR GASEOUS INDOOR-AIR POLLUTANTS

Takashi OYABU, CAI Kuiqian, Shozo ISHIZAKA, Haruhiko KIMURA*, Yoshinobu MATSUURA* and Yoshihisa KAJIYAMA*

Department of Sociology, Toyama University of International Studies
Oyama-cho, Toyama 930-12, Japan
* Department of Electrical and computer Engineering, Kanazawa University
Kanazawa, Ishikawa 920, Japan
** Figaro Engineering Inc.
Senbanishi, Minoo City, Osaka 562, Japan

Combustible gas (CGS), ammonia (AMS), carbon monoxide (COS), carbon dioxide (CO2S), nitrogen oxide (NXS), absolute humidity (AHS), relative humidity (RHS) and temperature (TMS) sensors are used to monitor indoor air-pollution. These sensors are connected to micro-computer through A-D converter. The system can measure the output of eight sensors for five gaseous indoor-air pollutants as a function of time. The pollutants are cigarette smoke, carbon dioxide gas, carbon monoxide gas, ethanol gas, commercial propane gas. CGS, AMS, COS, NXS are kinds of ceramic tin oxide gas-sensors. CO2S is electrolyte type. The daily periodical patterns of gas sensors are also measured in an experimental house and the pollutants are recognized by the system.

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12.
CO ƒZƒ“ƒT‚ɑ΂·‚éƒAƒ‹ƒR[ƒ‹–WŠQ‚Ìœ‹Ž

‹kìd˜YA’†ì‰pŒ³A’©‘qjŽ¡Ad·“OŽu*A•Ÿ“cŒ’ŽO

‰¡•l‘‘åHAVƒRƒXƒ‚ƒX“d‹@*

THE ELIMINATION OF ALCOHOL INTERFERENCE FOR A CO SENSOR

Shigeo KITSUKAWA, Hidemoto NAKAGAWA, Shukuji ASAKURA, Tesshi SHIGEMORI* and Kenzo FUKUDA

Department of Material Science and Chemical Engineering, Faculty of Engineering, Yokohama National University
Hodogaya-ku, Yokohama 240, Japan
* New Cosmos Electric Co., Ltd.
Yodogawa-ku, Osaka 532, Japan

The elimination method of alcohol interference for a sintered semiconductor CO sensor was explored. Nafion, known as a superacid, has been found to be a promising candidate. The ethanol interference was almost removed without sensitivity change to CO gas. This property was improved by the treatment to form the Nafion into complete H-type before measurement. The effective concentration range of this method covers a range in practical use.

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13.
ZnO ‚ð—p‚¢‚½”MüŒ^”¼“±‘ÌŽ®ƒKƒXƒZƒ“ƒT

—é–ØŒ’ŒáA‚“c@‹`

VƒRƒXƒ‚ƒX“d‹@

HOT WIRE SEMICONDUCTOR TYPE C2H4O SENSOR USING ZnO

Kengo SUZUKI and Tadashi TAKADA

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

The hot wire semiconductor type C2H4O (ethylene oxide) selective sensor was developed. ZnO resistivity was lowered by addition of Al2O3 or Ga2O3, and it was found that 2 mol% Ga2O3 doped ZnO was most adaptable to the hot wire semiconductor type sensor because of it's low conductivity. The present sensor had high sensitivity to sulfide compound gases or organic compound gases. For example, it was detectable to 1 ppm C2H4O. On the other hand the sensor had low sensitivity to hydrogen or hydrocarbon gases. It seemed that these sensing characteristics were dependent on oxidation activity of ZnO. The C2H4O selectivity was improved by formation of WO3-Al2O3 coating layer. The long term stabilities in the C2H4O sensitivity and the selectivity had been confirmed over 3 years.

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14.
CO ‘I‘ð«‚ð‰ü‘P‚µ‚½“d—¬ŒŸoŒ^ƒAƒ“ƒ`ƒ‚ƒ“Ž_Œú–ŒƒZƒ“ƒT

Œ´“c’B˜NA—ˆå‹M‹vAŽO‰Y‘¥—YAŽR“Y@úf

‹ã‘呇—H

IMPROVEMENT OF CO SELECTIVITY OF AMPEROMETRIC GAS SENSOR USING ANTIMONIC-ACID THICK FILM

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

An amperometric sensor using proton-conducting antimonic-acid thick-film can detect a small amount of H2 and CO in air at room temperature. However, it has rather low sensitivity to CO compared with that to H2, when attached with Pt electrodes. In order to improve the CO selectivity, the following two attempts were made. One was to use a couple of Pt-loaded oxide electrodes in place of the Pt electrodes. When 0.5 wt% Pt-WO3 and 0.5 wt% Pt-SnO2 were coupled, the CO sensitivity was found to be higher than the H2 sensitivity. Another was to disperse CO-active metal particles in the antimonic-acid film in the vicinity of Pt or Au electrodes. Among the colloidal noble metals tested, Ru was found to be the most effective for improving the CO selectivity.

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15.
Šó“y—ÞƒPƒCŽ_‰–‚Ì“±“d—¦‚ÆŽ_‘fƒZƒ“ƒT‚Ö‚Ì—˜—p

’†ŽR@‹A–ìG’Ê*A’艪–F•F**

•iì”’—ùŠ¢AV‹•l‚ê*Aˆ¤•Q‘åH**

OXYGEN IONIC CONDUCTORS BASED ON RARE EARTH-SILICATES, REx(SiO4)6Oy, AND APPLICATION TO O2 SENSORS

Susumu NAKAYAMA, Hiromichi AONO* and Yoshihiko SADAOKA**

Sinagawa Refractories Co. Ltd.
Bizen 705, Japan
* Department of Industrial Chemistry, Niihama National College of Technology
Niihama 792, Japan
** Department of Applied Chemistry, Faculty of Engineering, Ehime University
Matsuyama 790, Japan

Ionic conductivities were investigated for solid solutions of the rare-earth silicates RE10(SiO4)6O3 solid solutions and related compounds. The activation energy and conductivity at 500Ž estimated to be 69 kJ/mol and 1.8~10-4 S/cm for La10(SiO4)6O3 and 59 kJ/mol and 2.3~10-4 S/cm for Nd10(SiO4)6O3. The activation energy was increased and the conductivity was decreased by use of RE3+ with smaller ionic radius. The ionic transport number measured with an oxygen concentration cell was nearly 1 at 650Ž and the emf is sensitive to the oxygen partial pressure.

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16.
ƒiƒgƒŠƒEƒ€ƒCƒIƒ““`“±‘Ì‚ð—p‚¢‚½ CO2ƒZƒ“ƒT‚̉ž“š«

’艪–F•FAƒwƒ‹ ƒXƒvƒŠƒAƒgƒmAŽðˆä‹`˜YA¼Œû³M

ˆ¤•Q‘åH

A SOLID-STATE ELECTROCHEMICAL CO2 GAS SENSOR USING SODIUM IONIC CONDUCTORS

Yoshihiko SADAOKA, Heru SUPRIYATNO, Yoshiro SAKAI and Masanobu MATSUGUCHI

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

The response time is shortened by an increase in the flow rate of the test gases. Furthermore, the response time is prolonged when the working temperature decreased. Concentration dependence of the emf is expressed by emf (mV) = 547.5 - 74.0log[CCO2/ppm] at 470Ž when the flow rate of the test gases is set to 160 ml/min. The sensitivity, 74 mV/decade, fairly agrees with the theoretical value based on a two-electron electrochemical reaction.

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17.
ŒÅ‘Ì“d‰ðŽ¿Œ^ CO2ƒZƒ“ƒT‚Ì“Á«‰ü‘P

”g‘½–씎Œ›A—é–Ø—²”VA“ñ“c•äÏ

–îèŒvŠí

IMPROVEMENT OF SOLID ELECTROLYTE TYPE CO2 SENSOR

Hironori HADANO, Takayuki SUZUKI and Hozumi FUTATA

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

For the purpose of bringing a solid-electrolyte type carbon dioxide gas sensor into practical use, the said sensor should be capable of performing best under any condition and environment the sensor will undergo. Care must be taken not only for long-time stability but also for other characteristic properties of the sensor. Our study on this kind of sensor concentrated upon such problems as the characteristic sensitivity to miscellaneous gases, the initial stabilizing behavior, and sensitivity deterioration of the sensor laid in the high humidity atmosphere. Then we sought the best quality and performance. The sensitivity to miscellaneous gases has been much improved as the sensor is clad in an oxidizing catalyst, thus resulting in a fine quality of selectivity. Preparation of dense solid electrolyte makes for better initial stability of the sensor, and a replacement for the secondary electrode keeps the sensor from deterioration resulting from environmental exposure. Hence the sensor makes has been made more practical to use.

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18.
BaCe0.8Gd0.2O3-ƒ¿ŒÅ‘Ì“d‰ðŽ¿‚ð—p‚¢‚½Ž_‘fƒZƒ“ƒT“Á«

’JŒû@¸AˆÀ–{‰hˆêAŠ—¶FŽ¡

¼‰º“dŠíEŠÂ‹«ƒGƒlƒ‹ƒM[Œ¤‹†Š

SENSING PROPERTIES OF O2 SENSOR USING BaCe0.8Gd0.2O3-ƒ¿ CERAMICS AS ELECTROLYTE

Noboru TANIGUCHI, Eiichi YASUMOTO and Takaharu GAMO

Environment and Energy Res. Lab., Matsushita Electric Ind. Co., Ltd.
3-1 -1 Yagumo-nakamachi, Moriguchi, Osaka 570, Japan

In order to develop a new oxygen sensor in the place of zirconia type, limiting current-type oxygen sensors using BaCe0.8Gd0.2O3-ƒ¿(BCG) ceramics as electrolytes were constructed on traial and their sensing properties have been investigated. BCG ceramics exhibited high conductivities in the temperature range of 200Ž to 1000Ž and it was verified that the oxide ion could be conductive carrier in BCG under the oxygen existence at low temperature (400Ž). The oxygen sensors using BCGs worked and limiting currents increased linearly with increasing oxygen concentration in the range of 1-22% at 300Ž. They can respond within 30 sec, between 1% and 21% and humidity hardly affected the sensing performance. BCG seems to be a promissing electrolyte material for the oxygen sensor at low operating temperature (300Ž).

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19.
CoO-In2O3Œn•¡‡Ž_‰»•¨‚ð—p‚¢‚½—e—ÊŒ^ NOxƒZƒ“ƒT

ÎŒ´’BŒÈA²“¡‚µ‚Ì‚ÔA‘ê“c—Sì

‘啪‘åH

CoO-In2O3 MIXED OXIDE AS A CAPACITIVE TYPE NOx SENSOR

Tatsumi ISHIHARA, Shinobu SATO and Yusaku TAKITA

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

Mixed oxide of CoO and In2O3 was investigated as a capacitive type NOx sensor. Considering from the sensitivity and the period required for response and recover, the equimolar composition of CoO and In2O3 was the most suitable for the element of NOx sensor. It became evident that the element consisting of equimolar amount of CoO and In2O3 exhibit highly sensitive and selective for NO detection. In particular, the capacitance of CoO-In2O3 element was highly sensitive to NO but almost unaffected by NO2 provided that the element would be operated in the atmosphere without coexistence of oxygen. Consequently, there is a possibility that the concentration of NO and NO2 in NOx is separately determined from the capacitance of CoO-In2O3 element.

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20.
Œõ‰Ë‹´‚•ªŽq‚ð—p‚¢‚½—e—ÊŒ^Ž¼“xƒZƒ“ƒT i‹¤‘¶ƒKƒX‚̉e‹¿j

¼Œû³MAV–{ªŽjA’艪–F•FA•ŠâF˜N*AŽðˆä‹`˜Y

ˆ¤•Q‘åHAŽR•ƒnƒlƒEƒFƒ‹*

A CAPACITIVE-TYPE HUMIDITY SENSOR USING PHOTO-CROSS-LINKED POLYMER (EFFECT OF COEXISTENT ORGANIC VAPORS)

Masanobu MATSUGUCHI, Masafumi SHINMOTO, Yoshihiko SADAOKA, Takaaki KUROIWA* and Yoshiro SAKAI

Department of Applied Chemistry, Faculty of Engineering, Ehime University
Matsuyama, Ehime 790, Japan
* Fujisawa Factory, Yamatake-Honeywell Company, Limited
Fujisawa, Kanagawa 251, Japan

The cross-linked poly(vinyl cinnamate) was prepared by photoirradiation technique. The effect of irradiation condition on the degree of cross-linking and also on the sensing characteristics were examined. Further, the sorption behavior of various polar organic vapors, which had a different molecular size, in the cross-linked polymer was studied in order to examine a microstructure of the film and a cross sensitivity of this sensor. The cross-linked film was observed to behave like a molecular sieve. It was shown that higher cross-linking structure of the polymer evidently reduced the cross sensitivity, especially for large polar organic vapors.

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21.
ƒuƒƒ‚ƒNƒŒƒ][ƒ‹ƒOƒŠ[ƒ“/‚•ªŽq•¡‡–Œ‚ð—p‚¢‚½ŒõŠw“IƒAƒ“ƒ‚ƒjƒAƒZƒ“ƒT

’艪–F•FAƒj[ƒi ƒƒhƒŠƒQƒXAŽðˆä‹`˜Y

ˆ¤•Q‘åH

OPTICAL SENSOR FOR AMMONIA GAS IN AMBIENT USING BROMOCRESOL GREEN-ETHYLCELLULOSE COMPOSITE FILMS WITH ADDITIVES

Yoshihiko SADAOKA, Nena V.RODRIGUEZ and Yoshiro SAKAI

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

To detect ppm levels of ammonia in a dry ambient, optical changes in absorbance of bromocresol green dispersed in ethylcellulose with additives were examined. Without additives, the absorbance changes with ammonia gas were not so sensitive and recovery behaviour was not satisfactory. By using valinomycin as an additive, the response behaviour was drastically improved.

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22.
ƒ|ƒ‹ƒtƒBƒŠƒ“|‚•ªŽq•¡‡–Œ‚ð—p‚¢‚½‰–‘fA‰–Ž_ƒKƒX‚ÌŒõŠw“IŒŸo

’艪–F•FAƒj[ƒi ƒƒhƒŠƒQƒXAƒsƒGƒgƒ ƒ^ƒOƒŠƒAƒeƒXƒ^*

ˆ¤•Q‘åHA‘æ“ñƒ[ƒ}‘åŠw*

OPTOCHEMICAL HCl AND Cl2 SENSOR BASED ON IMMOBILIZED TETRA(PHENYL)PORPHYRINATES

Yoshihiko SADAOKA, Nena V. RODRIGUEZ and Pietro TAGLIATESTA*

Department of Applied Chemistry, Faculty of Engineering, Ehime University
Matsuyama 790, Japan
* Dipartiment di Scienze e Tecnologie Chimiche, II Universita degli di Roma
O0173, Italy

To detect sub-ppm levels of HCl and Cl2 gases, spectral changes in absorbance of some porphyrins and derivatives dispersed in ethylcellulose were examined. For Zn-tetraphenylporphyrin, the optical property is insensitive to HCl and sensitive to Cl2. The sensitivity to HCl and response behaviour are dramatically improved by bromination.

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23.
ƒ|ƒŠƒsƒ[ƒ‹–Œ‚ð—p‚¢‚½‘SŒÅ‘ÌŒ^ƒJƒŠƒEƒ€ƒCƒIƒ“‘I‘ð«“d‹É‚Ì“dˆÊƒhƒŠƒtƒg‹@\‚̉ðÍ

ŽR–{^—R”üA£ŽR—ÏŽqA‹îêTˆêA–åŠÔ‘”VAˆ§â“Nœ\

‘‘å—HEÞ—¿‹ZpŒ¤

ANALYSIS ON POTENTIAL DRIFT FOR ALL SOLID STATE POTASSIUM-SELECTIVE ELECTRODE USING POLYPYRROLE FILM

Mayumi YAMAMOTO, Michiko SEYAMA, Shin-ichi KOMABA, Toshiyuki MOMMA and Tetsuya OSAKA

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

All solid state potassium-selective electrodes were constructed by covering with a plasticized poly(vinyl chloride) (PVC) membrane containing valinomycin over the polypyrrole (PPy) film or the bare Pt electrodes. The electrode using PPy/poly(styrene sulfonate) composite underlayer indicated the Nernstian response and low drift of potential due to formation of stable concentration cell. The electrodes using the PPy doped with ClO4- or the bare Pt showed unstable potential. In this report, electrochemical characteristics of these systems were evaluated by ac impedance method with respect to the potential drift mechanisms.

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24.
e…«ƒ|ƒŠƒ`ƒIƒtƒFƒ“‚ð—p‚¢‚½ƒyƒ‹ƒIƒLƒVƒ_[ƒ[“d‹É‚É‚æ‚é
”ñ…—n”}’†‚Ì H2O2ƒZƒ“ƒVƒ“ƒO

—LŽR@ŒOA—§ŠÔ@“OA¬ŽR@¸

“Œ‹ž”_H‘åH

PEROXIDASE-INCORPORATED HYDROPHILIC PLOLYTHIOPHENE ELECTRODE FOR THE SENSING OF H2O2 IN NONAQUEOUS MEDIA

Kaoru ARIYAMA, Tetsu TATSUMA and Noboru OYAMA

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

Peroxidase-incorporated conducting polymer electrodes were examined as hydrogen peroxide sensors in acetonitrile. An aqueous solution containing horseradish peroxidase (HRP) and chemically polymerized poly(3-(3'-thienyl)propanesulfonic acid) (PTS) was cast on SnO2-coated glass plate to obtain HRP/PTS electrodes. The electrode exhibits cathodic current responses to hydrogen peroxide (†1ƒÊM) at +200-+500 mV vs. Ag/Ag+ in acetonitrile containing water (†l%) and 0.1 M supporting salt, NaClO4 or tetra-n-butylammonium perchlorate. The response was larger at a higher water content.

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25.
ƒyƒƒuƒXƒJƒCƒgŒ^Ž_‰»•¨’SŽƒJ[ƒ{ƒ““d‹É‚̉ߎ_‰»…‘fŒŸo‹““®

´…—zˆêA¬¼G‹IA“¹‰º‘ŽqAŽO‰Y‘¥—Y*AŽR“Y@úf*

H2O2 SENSING PROPERTIES OF CARBON ELECTRODE LOADED WITH PEROVSKITE-TYPE OXIDE

Youichi SHIMIZU, Hiroki KOMATSU, Satoko MICHISHITA, Norio MIURA*, and Noboru YAMAZOE*

Department of Chemistry, Faculty of Engineering, Kyushu Institute of Technology
Tobata, Kitakyushu-shi, Fukuoka 804, Japan
* Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

Carbon electrode loaded with perovskite-type oxide showed good properties of potentiometric as well as amperometric sensing to H2O2. EMF of the electrode using La0.6Ca0.4Ni0.7Fe0.3O3 was found to vary logarithmically with the H2O2 concentration between 10-5 and l0-3 M. The 90% response time was ca. 5 min at 25Ž. The electrodes loaded with large surface area perovskite-type oxides gave high activity to the electrochemical oxidation of H2O2. A Iimiting current was observed for most of the electrodes at the potential range between 0.6 and 1.0 V (vs. SCE) in the I-V characteristic curve. The sensing current of the electrode using La0.6Ca0.4MnO3 was found to be approximately proportional to H2O2 concentration up to 0.5 mM. The response time was as short as ca. 60 sec at 25Ž.

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26.
ƒ¿-ƒOƒ‹ƒRƒVƒ_[ƒ[/ƒsƒ‰ƒm[ƒXŽ_‰»y‘f‚ð—p‚¢‚½ƒ}ƒ‹ƒg[ƒXƒZƒ“ƒT

’h@‹à@AŽR–{MŽqA…’J•¶—Y*A–ê*

ƒeƒNƒmƒƒfƒBƒJŠJ”­ƒZA¶–½HŒ¤*

MALTOSE SENSOR WITH IMMOBILIZED BI-ENZYME MEMBRANE CONTAINING ƒ¿-GLUCOSIDASE AND PYRANOSE OXIDASE

Jinzong TAN, Shinko YAMAMOTO, Fumio MIZUTANI* and Soichi YABUKI*

Research and Development Center, Techno Medica Co. Ltd.. East Building 502 of Kanagawa Science Park (KSP), Takatsu-ku, Kawasaki, Kanagawa 213
* National Institute of Bioscience and Human-Technology. 1-1 Higashi, Tsukuba. Ibaraki 305

As the substitute for glucose oxidase, pyranose oxidase was used in fabricating maltose sensor. The sensor was constructed with a platinum base electrode and a bi-enzyme membrane containing ƒ¿-glucosidase and pyranose oxidase immobilized by polyvinyl alcohol having photosensitive stilbazolium group. The obtained sensor had a linear response to maltose up to I .5 mM with response time of 30 seconds and higher response current to maltose than to the same concentration of glucose, The sensor could be used for more than three months.

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27.
y‘fŒÅ’艻ƒ|ƒŠƒCƒIƒ“ƒRƒ“ƒvƒŒƒbƒNƒX–Œ‚ð—p‚¢‚½“ûŽ_ƒZƒ“ƒT

…’J•¶—YA–êA•½“c–FŽ÷

¶–½HŒ¤

L-LACTATE-SENSING ELECTRODE BASED ON A POLYION COMPLEX LAYER CONTAINING IMMOBILIZED LACTATE OXIDASE

Fumio MIZUTANI, Soichi YABUKI and Yoshiki HIRATA

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

An amperometric enzyme electrode for L-lactatic acid was prepared by immobilizing lactate oxidase (LOD) into a polyion complex membrane. First, an aqueous solution containing poly-L-lysine and LOD was placed on the surface of glassy carbon electrode, then an aqueous solution of poly(4-styrenesulfonate) was added to the solution and dried. The anodic current (at 1 V vs. Ag/AgCl) of this enzyme electrode increased immediately after the addition of L-lactic acid and the response time was shorter than 5 s. A linear response to L-lactic acid was observed up to 0.3 mM with a detection limit of 0.1ƒÊM. The enzyme electrode was applied to the determination of L-lactic acid in sera and sour milks: the polyion complex membrane showed permselectivity based on the solute size with the molecular cutt-off of ca. 100, which was very effective in supressing the electrochemical interference by L-ascorbic acid, uric acid and acetaminophen. The electrode could be used as least two months.

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28.
ƒvƒŒ[ƒiŒ^ƒAƒ“ƒyƒƒƒgƒŠƒbƒN“ûŽ_ƒZƒ“ƒT‚ÌŠJ”­

¼–{@’BAˆÉ“¡¬ŽjAŒy•”ª•v*

NEC Ž‘Œ¹Œ¤A“Œ‘åæ’[Œ¤*

A MICRO AMPEROMETRIC LACTATE SENSOR BASED ON A PLANAR PLATlNUM ELECTRODE

T. Matsumoto, N. Ito, I. Karube*
NEC Corporation
4-1-1 Miyazaki, Miyamae-ku, Kawasaki, Kanagawa 216, Japan
* University of Tokyo, RCAST
4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan

A micro planar amperometric biosensor has been developed for determining L-lactate concentrations. It consists of two platinum electrodes fabricated on a quartz substrate. The platinum electrodes are covered with an immobilized lactate oxidase membrane.
Hydrogen peroxide enzymatically produced from L-lactate in the enzyme immobilized membrane is electrochemically oxidized with the platinum electrode beneath the membrane. The oxidation current corresponds to lactate concentrations. L-lactate at concentrations from 0.05 to 1 mM can be measured with this biosensor. Interference substances at physiological concentrations have negligible effects on the biosensor. The biosensor output is stable for 150 days in storage at 2.5Ž.

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ŽóÜu‰‰ 2.
ƒfƒBƒXƒ|[ƒUƒuƒ‹ƒOƒ‹ƒR[ƒXƒZƒ“ƒT‚ÌŠJ”­‚ÆŽÀ—p‰»

“ìŠCŽj˜NA‹g‰ªr•FA‘«—§‹ÓˆêA’ç@Ž¡Š°*A¼–{M–ç*

¼‰º“dŠíŽY‹ÆA¼‰ºŽõ“dŽqH‹Æ*

DEVELOPMENT OF DISPOSABLE GLUCOSE SENSOR

Shiro NANKAI, Toshihiko YOSHIOKA, Kinichi ADACHI, Haruhiro TSUTSUMI* and Shinya NISHIMOTO*

Matsushita Electric Ind. Co., Ltd.
3-1-1 Yagumo-nakamachi Moriguchi-shi, Osaka 570, Japan
* Matsushita-Kotobuki Electronics Ind., Ltd.
2131-1 Minamikata, Kawauchi-cho, Onsen-gun, Ehime 791-03, Japan

A disposable glucose sensor based on amperometric enzyme electrode technology was developed and has been applied to blood glucose meter in diagnostic field. This sensor was constructed from a carbon electrode and a reaction layer containing hexacyanoferrate(III) as an electron mediator, glucose oxidase, a hydrophilic polymer and a cover. The sample is aspirated by capillary action into a chamber formed above the electrodes by the cover, and then measurement commences automatically, which limit user-induced variability. A glucose concentration in whole blood could be measured up to 500 mg/dl in 60 seconds. It was also confirmed that the initial response characteristics were retained for 18 months at 30Ž under dry condition.

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“Á•Êu‰‰ 2.
ƒAƒŒƒ‹ƒM[ƒZƒ“ƒT‚ÌŠJ”­

¼‰i@¥

“Œ‹ž”_H‘åH

RESEARCH AND DEVELOPMENT OF ALLERGY SENSOR

Tadashi MATSUNAGA

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

Many immunoassay methods have been developed for detecting allergens. A safe, simple and rapid method for detecting allergen is required in the clinical and food industry fields. We have developed a method for the electrochemical detection of allergen using RBL-1 cells and leukocytes based on cyclic voltammetry. In this paper, the electrochemical detection of allergen using human whole blood by microelectrode is reported. Serotonin, a mediator in allergic reaction, was used as a marker because it is electrochemically oxidized by applying constant potential at 0.35 V vs. Ag/AgCl. The detection of allergen was carried out by measuring the current after 40 min of incubation with allergen.

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29.
ƒVƒ…ƒEƒhƒ‚ƒiƒXƒtƒ‹ƒIƒŒƒZƒ“ƒX TN5 ‹Û‘̌Œèy‘f‹@”\“d‹É‚ð—p‚¢‚½
ƒjƒRƒ`ƒ“Ž_’è—Ê–@‚ÌŒ¤‹†

‚ŽRŸŒÈA’r“c“ÄŽ¡*A’·‘ò@“§**

•Ÿˆä‚êA‹ž‘å”_*A–¼‘å”_**

MEDIATED AMPEROMETRlC BIOSENSOR FOR NICOTINIC ACID ASSAY BASED ON WHOLE-CELLS OF PSEUDOMONAS FLUORESCENS TN5

Katsumi TAKAYAMA, Tokuji IKEDA and Toru NAGASAWA

Department of Industrial Chemistry, Fukui National College of Technology
Geshi-cho, Sabae-shi. Fukui 916, Japan
* Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University
Sakyo-ku, Kyoto 606, Japan
** Department of Agricultural Chemistry, Faculty of Agriculture, Nagoya University
Tigusa-ku, Nagoya 646-01, Japan

Whole cells of Pseudomonas fluorescens TN5 were immobilized on carbon paste electrodes containing p-benzoquinone by several methods using different kinds of membranes or not using a membrane. The electrodes with immobilized cells responded selectively to nicotinic acid, producing an anodic current when measured at 0.5 V with a responce time of about 2 min. Experimental results revealed that the reproducibility and the stability depend on the method of immobilization of the cells.

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30.
ŒÅ’艻ƒ¿-ƒAƒ~ƒ‰[ƒ[[“UƒJƒ‰ƒ€‚ð—p‚¢‚½ƒtƒ[ƒCƒ“ƒWƒFƒNƒVƒ‡ƒ“ƒJƒƒŠƒƒgƒŠ[

²“¡¶’jA—é–Ø’q°

_“ÞìH‰È‘åŠwEH‹Æ‰»ŠwHŠw‰È

FLOW-INJECTION CALORIMETRY USING A COLUMN PACKED WITH IMMOBILISED ƒ¿-AMYLASE

Ikuo SATOH and Tomoharu SUZUKI

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

Performance of a calorimetric flow injection system with use of ƒ¿-amylase covalently immobilized on porous glass beads was tested. The sensing system was assembled with the beads-containing column mounted in a flow-through type of calorimetric device for monitoring the enzyme activity. Change in temperature at the outlet of the column in an aluminum constant temperature bath was successively detected by a temperature probe. A fixed amount of l% starch solution was injected into the system, and then the effect of flow variables on the temperature response was investigated.

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31.
QCM ‚ð—p‚¢‚½ƒrƒIƒ`ƒ“‚̃oƒCƒIƒAƒtƒBƒjƒeƒB‘ª’è

›š@šõAANasson MarA¬”©‰p—AtŽR“N–çA‘ŠàV‰v’j

“ŒH‘嶖½—H

MEASUREMENT OF BIOAFFINITY OF BIOTIN BY QUARTZ CRYSTAL MICROBALANCE

Kyusik YUN, Mar MASSON, Eiry KOBATAKE, Tetsuya HARUYAMA and Masuo AIZAWA

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

The bioaffinity sensor was complexed between avidin and immobilized desthiobiotin onto the gold layer surface of a quartz crystal. The crystal was placed in a quartz crystal microbalance (QCM) flow cell. When a sample solution containing biotin was injected, the avidin was released from the surface to form a more stable complex with biotin in solution. The biotin concentration corresponded to the weight change on the crystal surface that occurred when avidin desorbed. Measurements were done in the stop-flow mode and in the continuous-flow mode. The sensor was regenerated without any loss in activity by readsorbing avidin.

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32.
…»U“®Ž® HSA ƒZƒ“ƒT‚ð—p‚¢‚½RŒ´R‘Ì”½‰ž‚Ì‘¬“x‰ðÍ

Žðˆä@„A²”Œ‹MLA‰F“c‘׎O*AŽO‰Y‘¥—YAŽR“Y@úf

‹ã‘呇—HAL“‡Œ§—§‘å*

KINETIC STUDY OF IMMUNOREACTIONS USING PIEZOELECTRIC HSA SENSOR

Go SAKAI, Takahiro SAIKI, Taizo UDA*, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan
* School of Bioresources, Hiroshima Prefectural University
Shoubara, Hiroshima 727, Japan

Binding of HSA (human serum albumin) to a monoclonal- and polyclonal-antibodies was examined by using a quartz resonator immunosensor on which immobilized monoclonal antibody was contacted to HSA and polyclonal antibody stepwise. The rate constants and association constants of both immunoreactions were obtained respectively from the initial rates and steady values of resonant frequency changes. The binding of HSA to the polyclonal antibody was shown to be much slower and weaker than that to the monoclonal antibody, probably owing to the steric hindrance and orientation effects of HSA already bound to the immobilized monoclonal antibody.

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