Vol. 12, Supplement A (1996)

Vol. 12, Supplement A (1996)

Proceedings of the 22nd Chemical Sensor Symposium
April 3-4, 1996
Tokyo University of Agriculture and Technology

Abstracts

1. SnO₂厚膜センサのエタノール感度特性に及ぼす拡散の影響

中川英元、土屋雅裕、作本弘司、朝倉祝治、福田健三、重盛徹志^*

横浜国大工、新コスモス電機^*

EFFECTS OF DIFFUSION ON ETHANOL GAS SENSING PRORERTIES OF SnO₂-BASED THICK FILM GAS SENSORS

Hidemoto NAKAGAWA, Masahiro TSUCHIYA, Koji SAKUMOTO, Shukuji ASAKURA, Kenzo FUKUDA and Tessi SIGEMORI^*

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

Effects of diffusion on gas sensing properties of SnO₂-based thick film gas sensors were investigated by measuring the resistance change with ethanol concentrations at various operating temperatures. SnO₂-based thick film sensors were fabricated by a screen printing method on alumina substrates. Ba was chosen to enhance catalytic activity for ethanol selectivity. The concentration dependence of the resistance was investigated at several temperatures. At 300℃ and 500℃, the resistance decreases almost linearly on a logarithmic scale, whereas at intermediate temperatures the concentration dependences showed non-linear character. The phenomenon suggested two different processes were dominating according to concentration ranges. The dependences may be elucidated by the competitive processes of surface consumption and diffusion.

To Japanese Contents

To English Contents

2. 半導体式ガスセンサの感ガス時におけるセンサ温度の低温へのシフト

高田　義

新コスモス電機

LOWER TEMPERATURE SHIFT OF SEMICONDUCTOR GAS SENSOR WHEN EXPOSED TO SAMPLE GASES
-Simultaneous Measurements of Sensor Temperature and Semiconductor Resistance Changes-

Tadashi TAKADA

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

Simultaneous measurements of sensor temperature change (△T) and semiconductor resistance change (△R) were carried out using SnO₂ based semiconductor gas sensor. The sensor structure used in the present study is illustrated in Fig.1. The alumina substrate is equipped with a pair of comb-type Pt film electrodes on the face and Pt film heater on the back. The heater simultaneously serves as a Pt film thermometer to measure the sensor temperature change. SnO₂ based semiconductor layer is formed over electrodes. Fig.1 also shows electrical circuit for the simultaneous measurements. Two reaction are important in considering reduced gases sensing characteristics of semiconductor gas sensor. One is the reaction of reduced gases on the semiconductor surface (and the interface between the semiconductor and Pt electrodes), which results in semiconductor resistance decrease, and the other reaction is the catalytic combustion on catalysts (exothermic reaction). It was found that the former reaction causing semiconductor resistance change gave rise to a lower temperature shift of the sensor temperature, that is, it was psued-endothermic. Therefore, psued-endothermic reaction always proceeds on the real sensors following catalytic combustion at the same time.

To Japanese Contents

To English Contents

3. 尿素均一沈殿法により調整した SnO₂のガス感度特性

松田大輔、松浦吉展、麻生　功

フィガロ技研

GAS SENSING CHARACTERISITICS OF SnO₂ PREPARED BY THE UREA HOMOGENEOUS PRECIPITATION METHOD

Daisuke MATSUDA, Yoshinobu MATSUURA and Isao ASO

Figaro Engineering Inc.
Mino-city, Osaka 562, Japan

The SnO₂ prepared by the urea homogeneous precipitation method (U1) showed higher sensitivity to CH₄ than the one prepared by the conventional method (A1). No differences were observed between U1 and A1 from the characterization by XRD, SEM and particle distribution measurement. However, the following points were clarified from the characterization of the Sn hydroxides of U1 and A1 (U1H and A1H, respectively) by XRD and XPS.

²⁺

_total

To Japanese Contents

To English Contents

4. NH₄⁺-Ga₂O₃を用いたアンモニアセンサ

今中信人、田村真治、足立吟也

阪大工

AMMONIA SENSOR BASED ON NH₄⁺-Ga₂O₃ SOLID ELECTROLYTE

Nobuhito IMANKA, 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 fabricated with the combination of NH₄⁺-Ga₂O₃ and rare earth (Pr, Nd) ammonium sulfate applied as a solid electrolyte and a reference electrode, respectively. The sensor output was consistent with the relation derived from Nernst equation. The sensor response was accurate and reversible with the NH₃ variation. Any interference with water vapor coexistence toward the sensing performance was not found at all even in a 4 vol% water vapor existing atmosphere.

To Japanese Contents

To English Contents

5. Ir/WO₃系素子におけるアンモニア昇温脱離スペクトルとガス応答

川副貴士、高尾雄二^*、清水康博、江頭　誠

長崎大工、長崎大海洋^*

TPD SPECTRA OF NH₃ FROM Ir/WO₃-BASED SPECIMENS AND THEIR AMMONIA SENSING PROPERTIES

Atsushi KAWASOE, Yuji TAKAO^*, Yasuhiro SHIMIZU, Makoto EGASHIRA

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

Temperature programmed desorption (TPD) spectra of gaseous species from NH₃-preadsorbed WO₃-based specimens have been investigated. Among WO₃-based specimens, 0.5Ir/WO₃ exhibited the smallest NH₃, and the largest N₂ and NO₂ desorption peaks. Thus, 0.5Ir/WO₃ was suggested to exhibit the highest activities for NH₃ oxidation as well as NO_x reduction under the atomosphere containing gaseous NH₃. When WO₃-based specimens was used as sensor materials, 0.5Ir/WO₃ single layer sensor exhibited the highest NH₃ sensitivity, as expected from the results of TPD spectra. The double layer sensor consisting of In₂O₃-MgO (5 mol%) sensing layer and 0.5Ir/WO₃ catalyst layer exhibited almost the same NH₃ sensing property as that of 0.5Ir/WO₃ single layer sensor.

To Japanese Contents

To English Contents

6. SnO₂系バリスタ型ガスセンサの H₂ガス検出特性に及ぼす貴金属の添加効果

金沢英一、高尾雄二^*、清水康博、江頭　誠

長崎大工、長崎大海洋^*

EFFECTS OF NOBLE METAL ADDITION ON H₂ SENSING PROPERTIES OF SnO₂-BASED VARISTOR GAS SENSORS

Eiichi KANAZAWA, Yuji TAKAO^*, Yasuhiro SHIMIZU and Makoto EGASHIRA

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

Current(I)-voltage(V) characteristics of SnO₂-based varistors have been investigated in air as well as in 0.2-2.0% H₂ at 300-600℃. SnO₂-based varistors exhibited a nonlinear I-V characteristic at temperatures less than 500℃ and a shift in breakdown voltage to a lower electric field in the presence of H₂. Addition of noble metals to SnO₂ resulted in a shift in breakdown voltage to a higher electric field in air. It was revealed that addition of Au to SnO₂ led to an increase in H₂ sensitivity, irrespective the amounts of Au up to 1.0 wt%. On the other hand addition of Pt or Pd to SnO₂ resulted in a decrease in H₂ sensitivity, and this behavior was much pronounced by the addition of lager amounts of metals.

To Japanese Contents

To English Contents

7. ハイシリカゼオライト被覆層を有する La₂O₃・Au-SnO₂系 CO センサ

福井　清、西田幸子

新コスモス電機

CO GAS SENSOR BASED ON La₂O₃-Au ADDED SnO₂ CERAMIC WITH SILICEOUS ZEORITE COAT

K. Fukui and S. Nishida

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

The CO selective gas sensor based on La₂O₃-Au/SnO₂ ceramic reported previously had a high selectivity to CO among H₂, CH₄, i-C₄H₁₀ and C₂H₄, but a high sensitivity to C₂H₅OH. In order to reduce the sensitivity to C₂H₅OH, an acidic catalyst layer converting C₂H₅OH into C₂H₄ by dehydration was formed on the sensing layer of the La₂O₃-Au/SnO₂ ceramic. The one of the siliceous zeorites was found to have a prominent ethanol filtering effect. The siliceous zeorite has hydrophobic property, a large specific area and thermal stability. Thus, a CO selective gas sensor with the sensitivity ratios over ten times high to the other gases was obtained under a steady operation.

To Japanese Contents

To English Contents

8. 電池駆動微小熱線型半導体式ガスセンサ

高田　義、塩沢浩明、小林博樹、丹上博雅

新コスモス電機

MINIATURIZED HOT WIRE TYPE SEMICONDUCTUOR GAS SENSOR OPERATED WITH A BATTERY

Tadashi TAKADA, Hiroaki SHIOZAWA, Hiroaki KOBAYASHI and Hiromasa TANJYOU

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

Miniaturized hot wire type semiconductor gas sensors (shown in Fig.1) have been developed to obtain various kinds of sensors with different gas selectivities operated with a small battery for a long term. The sintered SnO₂ bead of 150μm in diameter had a small power consumption of 60 mW at 500℃ of sensor temperature and also showed a sufficiently prompt response, and the response reached at a constant value within 200 msec when exposed to detected gases. The extremely lower power level operation (600μW of mean power consumption) was performed using a temperature pulse method (500℃ pulse of 200 mesc duration applied every 20 sec). More then 400 days have elapsed in this operation mode without any visible sensitivity-deterioration. The gas sensing characteristics of the miniaturized sintered SnO₂ bead became somewhat similar to that of thin film sensor, that is, high sensitivities to H₂, C₂H₅OH and organic solvent vapours. CH₄-selective and alkane-selective sensors were obtained by forming a Pd catalyst thin layer on the bead surface with electrodeposition method. These sensors would be possible to operate 666 days with two alkaline in series with 6.15 W/hour×2 (100 days have elapsed up to now).

To Japanese Contents

To English Contents

特別講演 1. 固体電解質ガスセンサの新展開

三浦則雄、山添　曻

九大総合理工

RECENT EVOLUTION OF SOLID ELECTROLYTE GAS SENSORS

Norio MIURA and Noboru YAMAZOE

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

The potentiometric solid-electrolyte gas sensors can be classified into three groups. Among them, the third group (Type III) sensor using an auxiliary phase is highly potential for constructing new type sensing devices. Recently we have been intensively focusing our efforts on developing high-performance sensors based on Type III for detecting environment-related gases, such as CO₂, NO_x, SO_x and so on. As a result, we have found that the selection of the auxiliary phase as well as the structure of the interface between the solid electrolyte used and the auxiliary phase are very important for the gas-sensing characteristics. The fabrication of new type sensors including "heterojunction" of an anion conductor and a cation conductor has also been shown to be possible. These achievements in Type III sensors will be introduced here, together with up-to-date results on new amperometric sensors as well as mixed-potential type sensors using oxide electrodes.

To Japanese Contents

To English Contents

9. 酸化インジウム系センサの二硫化ジメチル検知特性

阿部裕一、玉置　純、浅野泰一^*、林　研司^**、三浦則雄、山添　曻

九大総合理工、DKK^*、ニチレイ^**

SENSING PROPERTIES OF INDIUM OXIDE-BASED SENSORS FOR DIMETHYLDISULFIDE

Yuichi ANNO, Jun TAMAKI, Yasukazu ASANO^*, Kenji HAYASHI^**, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan
^* Research Center, DKK Corporation
Musashino, Tokyo 180, Japan
^** NICHIREI Corporation
Chuo-ku, Tokyo 101, Japan

Indium oxide-based sensors have been investigated for detecting dimethyldisulfide which is one of representative flavor components of beef consomme soup. It was found that the sensor element fabricated from the In₂O₃ powder calcined at 850℃ showed fairly good sensitivity and response rates to dimethyldisufide in wet air. In order to improve the sensing properties further, modification of the In₂O₃ powder with metal oxides and metal sulfates was attempted. Among the metal oxide additives tested, CuO brought about the highest sensitivity but small response rates to dimethyldisulfide at 200℃. On the other hand, metal sulfates were found to improve the sensitivity at higher temperatures. In particular, Na₂SO₄(5wt%)-In₂O₃ element gave satisfactory sensing characteristics to dimethyldisulfide in sensitivity, selectivity and response kinetics at 400℃.

To Japanese Contents

To English Contents

10. SnO₂(110)表面のエネルギーバンド計算

松嶋茂憲、小林健吉郎、岡田元次、白方　祥、香川正憲^*

愛媛大工、大工研^*

ELECTRONIC STRUCTURE OF THE (100) SURFACE OF TIN DIOXIDE

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

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

The electronic structure of the SnO₂ (110) surface with slab structure is calculated using a semiempirical tight-binding method. Surface states appear in the valence and the conduction bands. These states are strongly localized. Although the DOS (density of state) curve of the surface is broader than that of the bulk, some peaks and shoulders can be found in both the valence and the conduction bands. From the PDOS (partial density of state) analysis, it is found that the bound states in the valence-band region mainly arise form O2p orbitals and the bound states in the conduction-band region are mainly Sn5s orbitals.

To Japanese Contents

To English Contents

11. BaCe_0.8Gd_0.2O_3-αを用いた酸素センサの電極特性

中桐康司、谷口　昇、蒲生孝治

松下電器生活環境研究所

CHARACTERISTCS OF ELECTRODES FOR OXYGEN SENSOR USING BaCe_0.8Gd_0.2O_3-α CERAMICS

Yasushi NAKAGIRI, Noboru TANIGUCHI and Takaharu GAMO

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

Using BaCe_0.8Gd_0.2O_3-α(BCG) electrolyte which has higher ionic conductivity than Y₂O₃ stabilized ZrO₂ (YSZ), the limiting-current type oxygen sensors with various sintered metal electrodes were constructed and were examined as electrode materials for low temperature (300℃) operating sensors. Pt electrode had high activity but degraded quickly, on the other hand Au electrode was low active for oxygen but the sensor using it worked stably at 400℃. Furthermore, it is showed that Ag mixed with Pt electrode had high activity for oxygen. It is suggested that Au is a promising electrode material for BCG type oxygen sensor from the point of view of performance and durability when the activity is improved.

To Japanese Contents

To English Contents

12. NDV値によるガス状室内空気汚染物の同定

小野寺武^*1、大藪多可志^*1、蔡　奎千^*2、松浦吉展^*3、麻生　功^*3、木村春彦^*4

富山国際大人文^*1、富山大工^*2、フィガロ技研^*3、金沢大工^*4

INDENTIFICATION FOR GASEOUS INDOOR AIR-POLLUTANTS USING NDV

Takeshi ONODERA^*1, Takashi OYABU^*1, CAI Kuiqian^*2, Yoshinobu MATSUURA^*3, Isao ASO^*3 and Haruhiko KIMURA^*4

^*1 Toyama Univ. of International Studies
Oyama-cho, Toyama 930-12, Japan
^*2 Toyama Univ.
Gofuku, Toyama 930, Japan
^*3 Figaro Engineering
Senbansnishi, Minoo-shi, Osaka 562, Japan
^*4 Kanazawa Univ.
Kodatsuno, Kanazawa 920, Japan

Four kinds of tin oxide gas sensors are used to identify a kind of indoor air-pollutant in a domestic environment. They are combustible gas, ammonia gas, carbon monoxide gas and nitrogen oxide gas sensors. Eight pollutants are investigated using these sensors. This system can identify one kind of pollutant out of these pollutants. Three NDVs are adopted to identify a pollutant. NDV is a value which an output of a gas sensor is divided by the output of combustible gas sensor, namely NDV=V(a sensor)/V(combustible gas sensor). The characteristic of NDV varies with a pollutant. It becomes clear that three types of NDVs are effective in identifying one of these eight indoor air-pollutants.

To Japanese Contents

To English Contents

13. CeO₂/BaCO₃/CuO 混合粉末を用いた静電容量型炭酸ガスセンサ

松原正吾、金子信一郎、森本信司、志水章一、石原達巳^*、滝田祐作^*

九州松下電器、大分大工^*

CAPACITIVE TYPE CO₂ SENSORS USING CeO₂/BaCO₃/CuO MIXED POWDER

Shogo MATSUBARA, Shinichiro KANEKO, Shinji MORIMOTO, Shoichi SHIMIZU, Tatsumi ISHIHARA^* and Yusaku TAKITA^*

Material ＆ Component Research Laboratory, Kyushu Matshshita Electric Co., LTD.
Fukuoka 812, Japan
^* Faculty of Engineering, Oita University
Dannoharu 700, Oita 870-11, Japan

Mixed powder of CeO₂/BaCO₃/CuO, at a typical molar ratio of 63/6/31, have been investigated as a capacitive type CO₂ sensor. The sensitivity of C[in air]/C[at 2%-CO₂] at 550℃ was measured to bo 2.5 dB, and was not degraded in a reliability test in which the sensor without heating was kept at 85℃ under 90%RH for 1000 hr. Results of thermogravimetry and FT-IR suggested that CeO₂ played an important roll as catalysis to decompose BaCO₃ to BaO and CO₂.

To Japanese Contents

To English Contents

14. 金属炭酸塩補助相を有する固体電解質 CO₂センサの応答特性と界面構造

木田哲也、島ノ江憲剛、三浦則雄、山添　曻

九大総理工

GAS SENSING BEHAVIOR AND INTERFACIAL STRUCTURE OF SOLID ELECTROLYTE CO₂ SENSOR ATTACHED WITH METAL CARBONATE AUXILIARY PHASE

Tetsuya KIDA, Kengo SHIMANOE, Norio MIURA and Noboru YAMAZOE

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

CO₂ sensing behavior and interfacial structure were examined for the solid electrolyte CO₂ sensor which combined a NASICON based electrochemical cell with a metal carbonate (Na₂CO₃ or Na₂CO₃-BaCO₃). It was found that the Na₂CO₃-attached device had two gas sensitive interfaces, i.e., NASICON/Au electrode (O₂-sensitive) and Na₂CO₃/Au electrode (CO₂-sensitive). The latter interface dominated the sensing electrode potential in the high temperature region, which the former became dominant in the lower temperature region, leading to a complete loss in CO₂ sensitivity. The use of a binary carbonate, e.g., Na₂CO₃-BaCO₃, improved the CO₂ sensing properties especially at lower temperature. Such behavior could be well-understood through an analysis of the interfacial structure between NASICON and the metal carbonates.

To Japanese Contents

To English Contents

15. 安定化ジルコニアと酸化物電極を用いた混成電位型 NO_xセンサ

黒沢秀幸^*、廬　革宇、長谷井政治^*、三浦則雄、山添　曻

リケン^*、九大総理工

MIXED-POTENTIAL-TYPE NO_x SENSOR USING STABILIZED ZIRCONIA AND OXIDE SENSING ELECTRODE

Hideyuki KUROSAWA^*, Geyu LU, Masaharu HASEI^*, Norio MIURA and Noboru YAMAZOE

^* Riken Corporation
4-14-1 Suehiro, Kumagaya-shi, Saitama 360, Japan
Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

New type NO_x sensors ware designed by using stabilized zirconia and oxide sensing electrode. Among the various oxides examined, CdMn₂O₄ was found to be the most excellent material for the sensing electrode. Both planar and tubular device attached with a sputtered CdMn₂O₄ layer could respond well to NO₂ as well as NO in air at higher temperature such as 500℃. The EMF values of the devices were almost linear to the logarithm of NO_x concentration with a positive slope for NO₂ and a negative slope for NO. A NO_x sensing mechanism involving mixed potential was proposed based on the measurements of polarization curves.

To Japanese Contents

To English Contents

16. 電流検出型アンモニアガスセンサ

飯島鉄也、石地　徹

理研計器

AMPEROMETRIC AMMONIA GAS SENSOR BASED ON ELECTRODE OXIDATION OF RUTHENIUM OXIDE

Tetsuya IIJIMA and Toru ISHIJI

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

An amperometric sensor for NH₃ detection has been developed based on pH sensitive anodic reaction of RuO₂. The gas-permeable PTFE electrode with RuO₂ screen-printed responds to OH^- dissociated from the dissolved NH₃ into the solution (0.1 M KCl). The sensor could detect low concentration of NH₃ in the atmosphere, which sill be useful for NH₃ monitoring.

To Japanese Contents

To English Contents

17. 光学式酸性ガスセンサの開発－ポルフィリン－高分子複合膜の光学的性質

田中一成、五十嵐千秋、定岡芳彦^*、酒井義郎^*

（株）荏原総合研究所、愛媛工大^*

OPTOCHEMICAL ACIDIC GAS SENSOR BASED ON TETRAPHENYLPORPHYRINATES DISPERSED IN ETHYLCELLULOSE

Kazunari TANAKA, Chiaki IGARASHI, Yoshihiko SADAOKA^* and Yosiro SAKAI^*

Center for Environmental Engineering, Ebara Research Co., Ltd.
Fujisawa 251, Japan
^* Department of Applied Chemistry, Faculty of Engineering, Ehime University
Matsuyama 790, Japan

It is possible to detect sub-ppm levels of HCl gas with reversibility at room temperature for optochemical sensor based on tetraphenylporphine dispersed in ethyl cellulose film. The Soret and Q-bands of tetraphenylporphine are sensitive to HCl. The sensing characteristics were uninfluenced by coexistence of 2000 ppm H₂ or CO₂. For the element stored in ambient for 2 months no deterioration was detected. Substituent groups (-Br, -OH, etc.) replaced the hydrogen para to the phenyl group influence the sensitivity and response behavior.

To Japanese Contents

To English Contents

18. 高感度複合導波路の開発と応用

陳　暁民、卿　徳奎、伊藤公紀、村林眞行

横浜国大環境研

A HIGHLY SENSITIVE COMPOSITE OPTICAL WAVEQUIDE (TiO₂ FILM/K⁺ ION-EXCHANGE) AND ITS APPLICATION TO A REFRACTIVE INDEX SENSOR

Xiaomin CHEN, Dekui QING, Kiminori ITOH and Masayuki MURABAYASI

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

A highly sensitive composite optical waveguide was developed for sensor use by forming a thin TiO₂ film onto a K⁺-doped glass optical waveguide surface. The electric field of the evanescent wave on the film surface became stronger when the adiabatic transition was successfully operated. Furthermore, the intensity of the electric field was associated with the change of refractive index of clad layer (n_c). With this principle, the refractive index of the clad layer can be sensitivity monitored, and the sensitivity was estimated to be △n_c=10^-4-10^-3.

To Japanese Contents

To English Contents

19. 光架橋 PVCA を用いた容量型湿度センサ特性への膜厚の影響

松口正信、箕村雅巳、定岡芳彦、黒岩孝朗^*、酒井義郎

愛媛大工、山武ハネウェル^*

EFFECT OF THE FILM THICKNESS ON THE HUMIDITY SENSING CHARACTERISTICS OF THE CROSSLINKED PVCA FILM

Masanobu MATSUGUCHI, Masami MINOMURA, 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

Effect of the film thickness on the humidity sensing characteristics of the highly crosslinked PVCA film was examined. The thinner the film thickness, the higher the sensitivity. This is derived from the variation of water adsorption ability with the film thickness. The adsorption ability of the larger polar organic vapors on the film was considerably small because of the molecular sieve effect of the film. The thinner film was expected to be a selective humidity sensor from the standpoint of adsorption behavior. On the other hand, the dimensions of the thinner film were changed by exposing acetone vapor in the humid atmosphere. The film thickness determined as optimum for preparing a selective humidity sensor was 2μm.

To Japanese Contents

To English Contents

20. NO_xセンサ用銅フタロシアニン薄膜の表面形態とガス応答特性

竹内信弘、長沢　忠、村上健司、渡邉健蔵

静岡大電子研

SURFACE MORPHOLOGY AND GAS SENSITIVITY OF COPPER PHTHALOCYANINE THIN FILMS FOR NO_x GAS SENSOR

Nobuhiro TAKEUCHI, Tadashi NAGASAWA, Kenji MURAKAMI and Kenzo WATANABE

Research Institute of Electronics, Shizuoka University
3-5-1 Johoku, Hamamatsu 432, Japan

The copper phthalocyanine (CuPc) is the organic semiconductor which has higher thermal and chemical stability among other organic materials. The CuPc has been applied to gas sensor because its electrical conductivity is sensitive to absorption of various gases. Thin films of CuPc was deposited by the vacuum sublimation on glass substrates at different temperatures in order to realize the NO_x sensor which has a high sensitivity to the low gas concentration and operates at low temperatures.
In this paper, the crystalline structure and the surface morphology are analyzed by X-ray diffraction and scanning electron microscopy for thin CuPc films deposited at different temperatures (room temp., 70℃, 100℃, and 130℃). Furthermore, we discuss the relationship between above properties and the sensitivity to oxidizing gases such as NO₂, NO and O₂.

To Japanese Contents

To English Contents

21. プラズマ有機薄膜による化学センシング

杉本岩雄、中村雅之、桑野博喜

NTT 堺界領域研究所

CHEMICAL SENSING USING PLASMA ORGANIC FILMS

Iwao SUGIMOTO, Masayuki NAKAMURA and Hiroki KUWANO

NTT Interdisciplinary Research Laboratories
Musashino-shi, Tokyo 180, Japan

Plasma organic films produced by radio-frequency sputtering have great promising potentials in chemical sensing on the basis of their high solvation capacities for volatile organic compounds. Quartz crystal microbalances coated with plasma organic films show reliable mass transduction performance. The sputtered amino acid films have dipole-driven sorption characteristics, which are remarkable for phenylalanine and tyrosine films keeping their original structure substantially. Both of the amino acids containing benzene ring are resistive against carbonization decomposition induced by reductive elimination in plasmas. Conversely, the sputtered fluoropolymer films have polarizability-driven sorption characteristics, which are revealed by the sorption capacities for the simple hydrocarbons changing their molecular parameters systematically.

To Japanese Contents

To English Contents

22. 漆膜を塗布した水晶振動子式アルコールガスセンサ

南戸秀仁、近藤浩一、羽原正秋、森田　崇、山本　創、ルース・ウエイト^*1、筒口善央^*2、中澄博行^*3

金沢工大デバイス研、ローズ・ハルマン工科大学^*1、金沢工業試験場^*2、大阪府大^*3

GAS SENSING SYSTEMS FOR AROMAS OF ALCOHOLS USING JAPANESE-LACQUER-FILM-COATED QUARTZ-RESONATOR IN CONJUNCTION WITH PATTERN RECOGNITION ANALYSIS

H. NANTO, K. KONDO, M. HABARA, T. MORITA, H. YAMAMOTO, Ruth I. WAITE^*1, Y. DOUGUCHI^*2 and H. NAKAZUMI^*3

EDS Research Laboratory, Kanazawa Institute of Tech.
7-1 Oogigaoka, Nonoichi-machi, P.O. Kanazawa-South, Ishikawa 921, Japan
^*1 Rose-Hulman Institute of Tech.
5500 Wabash Avenue, Terre Haute, IN 47803, USA
^*2 Indust. Res. Institute of Ishikawa
1 Tomizu-machi, Kanazawa 920-02, Japan
^*3 Department of Applied Chemistry, University of Osaka Prefecture
4-804 Mozu-umemachi, Sakai, Osaka 591, Japan

The purpose of our research is to demonstrate a new aroma sensing method using Japanese-lacquer-film-coated quartz-resonator gas sensors in conjunction with associated pattern recognition technique to discriminate among different kinds of alcohol.

To Japanese Contents

To English Contents

23. 走査型微小電極を用いた水晶振動子の開発

山口秀一郎^*、塚原正紀、立間　徹、小山　昇
　
東京農工大工、（テルモ^*）

DEVELOPMENT OF SCANNING MICROELECTRODE QUARTZ CRYSTAL ANALYSIS SYSTEM

Shuichiro YAMAGUCHI^*, Masanori TSUKAHARA, Tetsu TATSUMA and Noboru OYAMA

Department of Applied Chemistry, Faculty of Technology, Tokyo University of Agriculture and Technology
Koganei, Tokyo 184, Japan
(^* Permanent Address: R & D Center, Terumo Co.; Nakai-machi, Ashigarakami-gun, Kanagawa 259-01, Japan)

Principles and methods for scanning electrode quartz crystal analysis (SEQCA) as a technique for mapping distribution of mass and interfacial rheology is described. In SEQCA, quartz crystal resonates in a region between a normal electrode and a microelectrode scanned over the opposite side of the normal electrode. The surface of the quartz crystal plate just below the scanning electrode is monitored. A prototype system for the scanning electrode quartz crystal analysis is constructed. Dependence of the resonance properties on the location of the scanning electrode is studied. As a result, it was found that the qualitative mapping of the mass distribution is possible in the resolution of 1 (9 MHz quartz) to 2 (5 MHz) mm. Viscoelastic properties of the load on the quartz surface are also measured qualitatively.

To Japanese Contents

To English Contents

24. GOx/AOx累積膜グルコースセンサー：アスコルビン酸による妨害の除去

竹下浩生、安斉順一、長　哲朗

東北大薬

GOx/AOx MULTILAYER-MODIFIED GLUCOSE SENSORS: ELIMINATION OF ASCORBATE INTERFERENCE

Hiroki TAKESHITA, Jun-ichi ANZAI and Tetsuo OSA

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

Glucose sensors are prepared by coating the surface of Pt electrode with enzyme multilayers composed of glucose oxidase (GOx) and ascorbate oxidasd (AOx), using an avidin-biotin technique. The GOx-AOx multilayer-modified glucose sensors which have 10-layer GOx and 5- or 10-layer AOx can be used for the determination of 3 μm - 10 mM glucose. A normal level of ascorbate in blood (ca. 0.1 mM) does not interfere with the measurement by the glucose sensor. The results are explained based on the fact that the immobilized AOx decomposes ascorbate effectively in the enzyme multilayers.

To Japanese Contents

To English Contents

25. ピラノースオキシダーゼ膜電極を用いたフローアンペロメトリックバイオセンサ

佐藤生男、佐藤高遠、栗原潤也

神奈川工科大学応用化学科

FLOW-AMPEROMETRIC BIOSENSOR WITH USE OF A PYRANOSE OXIDASE-MEMBRANE ELECTRODE

Ikuo SATOH, Takatoh SATOH and Jun-ya KURIHARA

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

Flow-amperometric biosensing of D-glucose was investigated with use of pyranose oxidase covalently immobilized onto a porous polymer membrane. The biosensing system was assembled with the membrane-covered polarographic oxygen electrode housed in a flow-through cell. Change in oxygen consumption was successively monitored at the outlet of the cell. The calibration graph was linear from 50μM (M=mol dm^-3) to 2.0 mM for 0.1 mL samples. The assay took within 2 min or shorter. The relative standard deviation for 2.0 mM D-glucose was found to be 0.2% (n=10). When stored at 4℃, the enzyme-membrane retained about 80% of its initial activity after 14 months.

To Japanese Contents

To English Contents

26. 電解重合ポリピロール/ポリイオンコンプレックス複合膜を用いた尿素センサ

駒場真一、瀬山倫子、田辺克久、逢坂哲彌、横田美穂^*、中村節子^*

早大理工・早大材料技術研、日本女子大理^*

UREA SENSOR BASED ON COMPOSITE FILM OF ELECTROPOLYMERIZED POLYPYRROLE AND POLYION COMPLEX

Shinichi KOMABA, Michiko SEYAMA, Katsuhisa TANABE, Tetsuya OSAKA, Miho YOKOTA^* and Sadako NAKAMURA^*

Department of Applied Chemistry, School of Science and Engineering; Kagami Memorial Laboratory for Materials Science and Technology, Waseda University
Shinjuku-ku, Tokyo 169, Japan
^* Department of Chemical and Biological Science, Faculty of Science, Japan Womens University
2-8 Mejirodai, Bunkyo-ku, Tokyo 112, Japan

A polyion complex film which consisted of polyacrylic acid, poly-L-lysine and urease (EC 3.5.1.5) was coated on the substrate platinum electrode, and the electropolymerization of pyrrole with a nucleophilic supporting electrolyte was performed and it showed a good urea response with the Nernstian slope of 98.1 mV decade^-1. Then this sensor was applied to flow injection analysis to attain a sequential and fast measurement.

To Japanese Contents

To English Contents

27. バイオセンサのための表面プラズモン共鳴センサの素子の基礎的研究

鈴木正康、森　悠丞、中島祐一

九州工業大学情報工学部

BASIC STUDY ON THE SENSING ELEMENT OF BIOSENSOR-AIMED SURFACE PLASMON RESONANCE SENSOR

Masayasu SUZUKI, Yusuke MORI and Yuichi NAKASHIMA

Department of Biochemical Engineering and Science, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology
Iizuka-shi, Fukuoka 820, Japan

Surface plasmon resonance (SPR) sensors are expected as real-time affinity sensors including immuno sensors. In this study, preparation procedures for the sensing element of SPR sensor aimed at biosensor applications were investigated. The adhesive layer between the gold layer and the glass substrate was investigated for aqueous phase applications. By the use of photoresist polymer as the adhesive layer, good adhesion was achieved and sharp SPR absorption peaks could be obtained. This sensing element was applied to the antigen-antibody reaction measurement. Human IgG could be determined by the use of the sensing element that anti human IgG antibodies were immobilized by the mercaptide formation.

To Japanese Contents

To English Contents

28. SPR方式免疫センサの開発と基本特性（I）

市川幸子、金岡智己^*、外山　滋、山内　繁、碇山義人

国立リハビリ研、東洋大工^*

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

Sachiko ICIKAWA, Tomoki KANAOKA^*, Shigeru TOYAMA, Shigeru YAMAUCHI and Yoshihito IKARIYAMA

National Rehabilitation Center for the Disabled
4-1 Namiki, Tokorozawa 359, Japan
^* Department of Applied Chemistry, Faculty of Engineering, Toyo University
2100 Kujirai, Kawagoe 350, Japan

Realtime and nonlabelled detection of antigen/antibody are described by a surface plasmon resonance(SPR)-based optical biosensor. SPR signal was drastically sensitized by improving software. For the detection of large immunoresponse by the SPR sensor, it is necessary to immobilize antigen/antibody as much as possible into polymer matrix having low refractive index. Covalent binding of oxidized hydroxyethylstarch polymer was performed onto thin gold film surface via self-assembled monolayer of aminoethanethiol.

To Japanese Contents

To English Contents

29. 表面プラズモン共鳴を利用するエイズウイルスコアータンパクp24抗体の測定

窪田就彦、西村知晃、一二三恵美、清水浩輔、宇田泰三

広島県立大生物資源

SENSING OF THE ANTIBODY AGAINST AIDS VIRUS CORE PROTEIN p24 USING SURFACE PLASMON RESONANCE

Naruhiko KUBOTA, Tomoaki NISHIMURA, Emi HIFUMI, Kousuke SHIMIZU and Taizo UDA

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

One of the AIDS virus core protein, p24, and its antibody were employed in a study on the AIDS sensor using surface plasmon resonance. Gold surface of the sensor chip was treated with 3-carboxypropyl disulfide, N-hydroxysuccinimide and EDC and then the antigen, p24, was chemically fixed. In the sensor, anti p24 antibody could be detected ranging from 0 to 40μg/ml. The influence of serum on the reflectance was examined for the purpose of practical application. Human serum influenced both the sensitivity to and the detection range for the antibody in SPR measurement. However, when the human serum is treated under the condition of 56℃-30 min, non-specific reaction was considerably eliminated. The antibody in the human sera samples could be quantitatively detected and the sensitivity was increased one and half times as compared with by using the non-inactivated serum.

To Japanese Contents

To English Contents

受賞講演． アンペロメトリックバイオセンサの高機能化の研究

矢吹聡一

工技院生命研

DEVELOPMENT OF AMPEROMETRIC BIOSENSORS WITH HIGH-PERFORMANCE

Soichi YABUKI

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

This paper reviews our latest studies on the development of amperometric biosensors with high-performance: we used i) the electro-conductive materials for immobilization matrixes of enzyme, ii) enzymes which was modified with polyethylene glycol, and iii) novel electron mediator for development of biosensors. In this paper, these three points is explained by giving examples.

To Japanese Contents

To English Contents

特別講演 2. 医療と化学センサー：臨床検査領域からの開発ニーズを巡って

戸谷誠之

国立健康栄養研

EXPECTATION OF CHEMICAL SENSING SYSTEMS FOR LABORATORY MEDICINE

Masayuki TOTANI

Division of Material and Child Health Science, National Institute of Health and Nutrition
Shinjyuku-ku, Tokyo 162, Japan

Electric Chemical Sensor is useful technical seeds for the assay of human biological constituent for vital sign. It has already passed more than 30 years since the practical use of chemical sensor was first published for the determination of blood glucose. However any remarkable progress has not been made in this technique in spite of the great needs in the field of chemical laboratory. What kind of the development of the sensor would be desired by laboratory workers? I would like to clarify the history of medicine and the progress of the scientific method and to comment the future prospect.

To Japanese Contents

To English Contents

30. コレステロールセンサの開発（I）

山本智浩、池田　信、吉岡俊彦、南海史郎、岩田潤子^*、上甲茂樹^*

松下電器、松下寿電子工業^*

DEVELOPMENT OF CHOLESTROL SENSOR (REPORT I)

Tomohiro YAMAMOTO, Shin IKEDA, Toshihiko YOSHIOKA, Shiro NANKAI, Junko IWATA^* and Shigeki JOKO^*

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

In this study, we characterized the cholesterol assay system using cholesterol dehydrogenase (CDH) for development of O₂-insensitive disposable cholestrol sensor.
In the case of Fe(CN)₆^3- as an electron mediator, the steady-state current response due to oxidation of cholestrol via CDH, NADH and Fe(CN)₆^3- was observed. The effect of diaphorase on the assay system was also examined. It could be found that the introduction of diaphorase to the system contributes to promotion of the mediated enzyme reaction. It showed a relatively rapid response time, reaching 80% of the steady-state current within a minute.
Capability of mediator was also studied for other redox compounds. The current response due to mediated enzyme reaction was observed using thionine, 1-methoxy-5-methylphenazinium methyl sulfate, 2,6-dimethyl-p-benzoquinone and so on, as an electron mediator.

To Japanese Contents

To English Contents

31. ポリイオンコンプレックス担体を利用したアルコールセンサ

水谷文雄、矢吹聡一、平田芳樹

生命工研

ALCOHOL-SENSING ENZYME ELECTRODE USING POLYION COMPLEX SUPPORT

Fumio MIZUTANI, Shoichi YABUKI and Yoshiki HIRATA

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

An amperometric enzyme electrode for alcohol was prepared by immobilizing alcohol oxidase in a polyion complex membrane. An aqueous solution containing poly(4-styrenesulfonate), that containing alcohol oxidase and that containing poly-L-lysine were successively placed on a platinum electrode and then dried. The anodic current (at 0.7 V vs. Ag/AgCl) of this enzyme electrode increased immediately after the addition of alcohol (methanol or ethanol) and the response time was <5 s. A linear response to ethanol was observed up to 0.4 mM with a detection limit of 0.05μM. The polyion complex membrane showed permselectivity based on the solute size with the molecular cut-off of ca. 100, which was effective in suppressing the electrochemical interference by L-ascorbic acid. The enzyme electrode was applied to the determination of ethanol in alcoholic drinks. The electrode could be used for two weeks.

To Japanese Contents

To English Contents

32. 印刷法によるグルコースセンサの作製プロセス

新井潤一、日野好弘、相澤益男^*

凸版印刷　東工大生命理工^*

Production Process of Glucose Sensor by Printing Method

Junichi ARAI, Yoshihiro HINO and Masuo AIZAWA^*

Toppan Printing Co., Ltd.
4-2-3 Takanodaiminami, Sugito-mati, Kitakatsushika-gun, Saitama 345, Japan
^* Department of Bioengineering, Tokyo Institute of Technology
4259 Nagatsuta, Midori-ku, Yokohama 226, Japan

A production process of an enzyme sensor for glucose has been developed on the basis of the printing method. The electrode was constructed by a single layer of printed ink containing carbon, glucose oxidase, and ferrocene as an electron mediator. The sensor responded linearly in output current to glucose concentration in the range to 500 mg/dl. This method seems feasible in mass production.

To Japanese Contents

To English Contents

33. 低電位作動型血糖値センサに関する研究

外山　滋、千須和幸直^*、山内　繁、碇山義人

国立リハビリ研、埼玉工大工^*

LESS POSITIVE POTENTIAL WORKABLE BLOOD GLUCOSE SENSOR

Shigeru TOYAMA, Yukinao CHISUWA^*, Shigeru YAMAUCHI and Yoshihito IKARIYAMA

Research Institute, National Rehabilitation Center for the Disabled
4-1 Namiki, Tokorozawa 359, Japan
^* Department of Environmental Engineering, Saitama Institute of Technology
1690 Fusaiji, Okabe, Saitama 369-02, Japan

Glucose sensor based on carbon paste containing nickelocene, glucose oxidase, and platinum particle is reported. The sensor response depended on glucose concentration in serum. The working potential was -200 mV vs. Ag/AgCl, much lower than that of conventional ones. Also, the sensor response was unaffected by ingredients in blood, such as ascorbic acid. The sensor output current suffered no effect under nitrogen bubbling, but it decreased under air bubbling. However, it was shown that the oxygen dissolved in a sample has no influence as long as the sample volume was small.

To Japanese Contents

To English Contents

To On-line Chemical Sensors Index Page (Japanese)

To On-line Chemical Sensors Index Page (English)