Vol. 16, Supplement B (2000)

Proceedings of the 31st Chemical Sensor Symposium
September 12-13, 2000

Abstracts

1.

DNA/ポリカチオン累積膜を感応素子とする酵素センサ

長谷部 靖、最上　博考、内山 俊一

埼玉工大・工

AN ENZYME SENSOSR USING DNA/POLYCATION FILMS AS SENSING ELEMENTS

Yasushi HASEBE, Hirotaka MOGAMI and Shunichi UCHIYAMA

Department of Applied Chemistry, Faculty of Engineering, Saitama Institute of Technology
1690, Fusaiji, Okabe, Saitama 369-0293, Japan

A second generation reagentless H2O2 biosensor was prepared by immobilizing horseradish peroxidase (HRP) on a polyion complex membrane consisted of double stranded DNA (dsDNA) and polyallylamine (PAA). Cyclic voltammetry (CV) indicated that the electron-transfer mediator, meldola's blue (MdB) which was intercalated with dsDNA in the film efficiently mediates electrons from the Au electrode to the redox active center of the HRP. The resulting electrode (HRP/DNA-MdB/PAA exhibited amperometric responses to H2O2 with the relatively fast response time of ~10 s in the concentration range from 1x10-6 M to 5x10-4 M (M = mol dm-3) with a detection limit of 5x10-7 M H2O2 in 0.1 M phosphate buffer (pH 7.0).

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2.

尿素検出を目的としたpHスタット型フローアンペロメトリックセンシングシステムの開発

米山健司，山田祐規子，小岩一郎，逢坂哲彌，佐藤生男*

早稲田大学理工，早稲田大学材料技術研，神奈川工科大工*

THE CONSTRUCTION OF THE pH STAT FLOW AMPEROMETRIC SENSING SYSTEM FOR THE DETECTION OF UREA

Kenji YONEYAMA, Yukiko YAMADA, Ichiro KOIWA, Tetsuya OSAKA, Ikuo SATOH*

Department of Applied Chemistry, School of Science and Engineering; Kagami Memorial Laboratory for Materials and Technology, Waseda University
Shinjuku-ku, Tokyo 169-0051, Japan
*Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute of Technology
Atsugi-shi, Kanagawa-ken, 243-0292, Japan

A novel flow cell using ion sensitive field effect transistor (ISFET), we just call FET cell in the following parts, was fabricated. It is used for mixing the sample solution with the generated hydrogen ion solution and used for the pH detection. An amperometric sensing system based on the pH-stat method and flow injection analysis (FIA) was constructed using the fabricated FET cell. In this study, alkaline sample was used as a simulate conditions of urea hydrolysis for the confirmation of the function of the constructed system. The linear calibration between the alkaline sample and the current response was obtained up to 600 μM. The relative standard deviation for thirty amperometoric measurements of standards alkaline sample was 4.35 %. It exhibited the long-term operational stability of the constructed system.

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3.

pHスタット型フローアンペロメトリックセンシングシステムの尿素分析への応用

米山健司，山田祐規子，小岩一郎，逢坂哲彌，佐藤生男*

早大理工，早大材研，神奈川工大工*

APPLICATION OF THE pH-STAT FLOW AMPEOMETRIC SENSING SYSTEM FOR UREA DETECTION

Kenji YONEYAMA, Yukiko YAMADA, Ichiro KOIWA, Tetsuya OSAKA, and Ikuo SATOH*

Department of Applied Chemistry, School of Science and Engineering; Kagami Memorial Laboratory for Materials Science and Technology, Waseda University
Shinjuku-ku, Tokyo 169-0051 , Japan
*Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute of Technology
Atsugi-shi, Kanagawa-ken 243-0292, Japan

We investigated the long-term operational stability (long-term stability of immobilized urease and reproducibility of amperometric urea response) and the influence of the interfering substance (i.e. ascorbic acid: AA ) using the constructed amperometric urea sensing system based on the pH-stat method and flow injection analysis (FIA). A linear calibration was obtained between urea concentration(100～800 μM) and current response. The relative standard deviation for fifteen amperometric measurements of 100 μM urea sample was 5.64 %. Then the influence of AA on urea response was investigated using two different concentrations of phosphate buffer solution;10 and 50 mM PBS. In the case of 10 mM PBS, no potential response was obsereved in 50 μM AA. On the other hand, in the case of 50 mM PBS, it was confirmed that 90 μM AA did not cause any potential response. Therefore, it was proved that AA did not influence the current response until 50 μM in 10 mM PBS and 90 μM in 50 mM PBS.

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4.

耐熱性酵素を用いたグルコース、スクロース及びマルトースの表面光電圧法による同時 計測特性

青木一仁、内田秀和、勝部昭明、石丸雄大、飯田武揚

埼玉大工

CHARACTERIZATION OF THE INTEGRATED SURFACE PHOTOVOLTAGE SENSOR FOR THE SIMULTANEOUS DETECTION OF GLUCOSE, SUCROSE AND MALTOSE USING THERMOSTABLE ENZYMES

Kazuhito AOKI*, Hideaki UCHIDA**, Teruaki KATSUBE**,Yoshihiro ISHIMARU*, and Takeaki IIDA*

* Department of Functional Materials Science ,** Department of Information and Computer Sciences ,Faculty of Engineering, Saitama University
255 Shimo-okubo, Urawa-shi, Saitama-ken 338-8570, Japan

Surface photovoltage (SPV) technique was applied to the integrated saccharide sensor. The thermophilic glucokonase was immobilized with BSA and glutaraldehyde on the SPV chip as glucose sensor, which responded to glucose at the pH of 6.4-9.1 and there was few influence on the salt concentration. The SPV glucose sensor was constructed for some saccharide sensors using the various hydrolases. The integrated saccharide sensor was able to detect simultaneously glucose, sucrose and maltose using immobilization of thermostable hydrolases such as invertase andα-glucosidase. The detection limits for each saccharide were improved by the increase in the LED current. In the detection of mixture sample, it was found that few inhibition was observed between sucrose and maltose.

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5.

耐熱性プロテアーゼ：サーモリシンを用いたタンパク質測定用バイオセンサ

的場 孝盛、石丸 雄大、飯田 武揚

埼玉大工

CHARACTERISTICS OF A PROTEIN SENSOR FOR MONITORING VARIOUS PROTEINS USING THERMOPHILIC PROTEASE：THERMOLYSIN

Takamori MATOBA, Yoshihiro ISHIMARU, and Takeaki IIDA

Department of Functional Materials Science, Faculty of Engineering,Saitama University
Shimo-okubo, Urawa-shi, Saitama-ken 338-8570, Japan

An ion sensitive field effect transistor (ISFET) type protein sensor was studied using a thermophilic protease：thermolysin. The sensor was able to monitor various proteins e.g. casein，gluten，et al.，each concentration was 0.05wt%(5mg/10ml) and 0.01wt%(1mg/10ml) at 35℃. It was found that hydrogen ions were released when the thermolysin hydrolyzes the peptide bonds. In this report，the characteristics of the thermolysin based sensor were investigated.

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6.

大腸菌を用いた微生物チップによるバイオアッセイ

彼谷高敏，西澤松彦，安川智之，丹羽和裕*，西口昌志*，小野内　徹*，末永智一

東北大院工，松下精工*

BIOASSAY USING MICROBIAL CHIP WITH E.COLI SPOTS

Takatoshi KAYA, Matsuhiko NISHIZAWA, Tomoyuki YASUKAWA, Kazuhiro NIWA, Masashi NISHIGUCHI, Tooru ONOUCHI, and Tomokazu MATSU

Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University
AramakiAoba07, Aoba-ku, Sendai 980-8579, Japan

Microbial chips for bioassay were fabricated and their performance was characterized by scanning electrochemical microscopy (SECM). The microbial chips were prepared by spotting E.coli or S.aureus suspension onto a polystyrene substrate, followed by treated with immobilization reagents. The respiration activity of the microbial spots at the chip was imaged with SECM based on oxygen reduction current. The images of the microbial chips clearly showed spots with lower reduction currents, indicating that E.coli or S.aureus in the spots actively uptake oxygen by respiration. The bactericide effects of ethanol, ampicillin, and streptomycine were estimated using these microbial chips.

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7.

フェロセン標識抗体を用いた免疫センサの開発

◯安澤幹人、三井　光、大賀敬介、椚　章

徳島大工

DEVELOPMENT OF IMMUNOSENSOR USING FERROCENE-LABELED ANTIBODIES

Mikito YASUZAWA, Hikari MITSUI, Keisuke Oga and Akira KUNUGI

Department of Chemical Science and Technology, Faculty of Engineering, The University of Tokushima
2-1 Minamijosanjima, Tokushima 770-8506, Japan

An amperometric immunosensors for the quantification of transferrin was fabricated using two monoclonal IgG class anti-rat transferrin antibodies, 15C2H3 and 22A06D2. The former was immobilized on a gold electrode (gold=antibody) while the latter was conjugated with the positively charged polymers containing ferrocenyl groups (antibody=ferrocene). The quantitative analysis of transferrin was investigated by measuring the electrooxidation current of ferrocene, which is proportional to the transferrin concentration for the equivalently observed sandwich formation (gold=antibody-antigen-antibody=ferrocene). The deposition of electroconductive polymer, poly[ferrocenylmethyl-3-(pyrrol-1-yl)propyldimethylammonium bromide] (poly-FP), on the surface of gold=antibody before the sandwich formation not only increased the sensor response, but also eliminated the nonspecific binding of antibody=ferrocene by a mutual repulsion. The sensitivity of the prepared sensors was 15 times higher than that of monomers conjugated sensors.

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特別講演

電流検出型の酸センサ

楠　文代

東薬大薬

AMPEROMETRIC ACID SENSOR

Fumiyo KUSU

School of Pharmacy, Tokyo University of Pharmacy and Life Science
1432-1,　Horinouchi, Hachioji, Tokyo 192-0392, Japan

Amperometric acid sensors of three-electrode type were developed, based on measurement of reduction prepeak current of quinone in the presence of acid in an unbuffered solution. A handy-type acid sensor, composed of small electrolytic equipment, electrode, and quinone solution containing 3,5-di-t-butyl-1,2-benzoquinone (DBBQ), could be applied to monitoring total acid concentration in orange juice or wine. A flow-type acid sensor was used for measuring acid value of fats and oils by flow injection analysis and for determining free higher fatty acids by high-performance liquid chromatography. The sensors are superior to the conventional titration method with respect to a sensitive, rapid, and simple means for acid assay.

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清山賞受賞講演

新型イムノセンサに向けた抗体酵素の作製と今後の展望

宇田 泰三

広島県立大生物資源

Design and view of catalytic antibody for the development of new immunosensor

Taizo UDA

School of Biosciences, Hiroshima Prefectural University
Shoubara-shi, Hiroshima 727-0023, Japan

A novel antibody whose light chain could enzymatically decompose the antigenic peptide (gp41 peptide of HIV-1) was obtained by the immunization of ground state-peptide molecule. The unique antibody light chain (41S-2-L:super catalytic antibody), exhibited to destroy the targeted intact gp41 molecule, too. This is the first case that the catalytic antibody decomposed the targeted protein. The 41S-2-L showed a protease like feature for the destruction of the targeted antigens. The enzymatic activity of 41S-2-L displayed a high kcat/Km value as being 2.8 x 105/M/min, which is comparable to the activity of trypsin (a natural protease). This method is very superior compared with the transition state analogue method for the production of the novel and characteristic catalytic antibody. As the 41S-2-L converted the antigenic peptide amino acids and small peptides, the detection of the converted amino acids is one of the candidates in order to fabricate a new immunosensor using the super catalytic antibody.

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清山賞受賞講演

迅速クーロメトリックセンサの実用化と新規バイオセンシング法の開発

内山俊一

埼玉工大工

DEVELOPMENT OF RAPID COULOMETRIC SENSOR AND NOVEL BIOSENSING METHODS

Shunichi UCHIYAMA

Department of Applied Chemistry，Faculty of Engineering, Saitama Institute of Technology
1690 Fusaiji, Okabe, Saitama 369-0293, Japan

Most of the conventional chemical sensors need calibration curve to calculate the analytical values of chemical species. On the other hand, coulometry using carbon felt electrode impregnated with an electrolyte can get analytical values rapidly without calibration, because the absolute determination of the sample is easily possible. This research focuses on development of commercial available rapid coulometric chemical sensor. Moreover, our trials to enhance the sensitivity of enzyme electrode and other our researches on novel biosensing method using biological tissues as biological catalysts are described.

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8.

水晶振動子の溶液中での共振特性に関する研究

黒澤　茂、猿楽善己*、愛澤秀信、吉本　稔*、平川廣満*

物質研・鹿児島大院理工*

STUDY OF THE CHARACTERISTICS OF THE RESONANCE ON THE QUARTZ CRYSTAL MICROBAL ANCE IN A SOLUTION

Shigeru KUROSAWA， Yoshimi SARUGAKU， Hidenobu AIZAWA， Minoru YOSHIMOTO， and Hiromitsu HIRAKAWA

National Institute of Materials and Chemical Research
1-1 Higashi，Tsukuba，Ibaraki 305-8565, Japan

We examined in the sucrose solution the characteristics of the resonance on the AT-cut quartz crystals on the fundamental frequencies 5MHz, 9MHz, 15MHz and 30MHz. We especially studied the characteristics of the resonance on the overtone m ode of 5MHz and 9MHz. These results showed that the sensitivity increased with the resonance frequ ency and that the shift of the resonance frequency in the N times overtone m ode was √N times lager than that in the fundamental mode.

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9.

超高周波水晶振動子の溶液中での共振特性に関する研究

黒澤　茂、中島範昭*、愛澤秀信、韓　大相、吉本　稔*

物質研・鹿児島大院理工*

STUDY OF THE CHARACTERISTICS OF THE RESONANCE ON THE QUARTZ CRYSTAL MICROBALANCE WITH ULTRAHIGH FREQUENCY IN A SOLUTION

Shigeru KUROSAWA， Noriaki NAKASHIMA， Hidenobu AIZAWA， Dae-Sang HAN, and Minoru YOSHIMOTO

nal Institute of Materials and Chemical Research
1-1 Higashi， Tsukuba， Ibaraki 305-8565, Japan

The measurement of the viscosity useful for checking the purification of oil. We studied the viscosity of a sucrose solution using the fundamental and the overtone modes of the AT-cut quartz crystals with ultrahigh frequencies. As results, it became clear that these quart crystals were available to the viscosity sensor.

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10.

超高周波数水晶振動子の質量感度に関する研究

黒澤　茂、東　昇平1、愛澤秀信、韓　大相、吉本　稔1

物質研、鹿児島大院理工1

STUDY OF THE MASS SENSITIVITY OF THE QUARTZ CRYSTAL MICROBALANCE WITH THE UL TRAHIGH FREQUENCY

Shigeru KUROSAWA, Shohei HIGASHI, Hidenobu AIZAWA,Dae-Sang HAN , and Minoru YOSHIMOTO

National Institute of Materials and Chemical Research
1-1 Higashi，Tsukuba，Ibaraki 305-8565, Japan

We investigated the fundamental and the overtone modes of the AT-cut quartz crystals with ultrahigh frequencies. These experiments indicated that, in th e same frequency, the fundamental mode was more sensitive than the overtone mode. It became clear that the fundamental mode of the AT-cut quartz crystal with a ultrahigh frequency was suitable for the mass sensor with the high r esponse.

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11.

アポ酵素活性化法によるフェムトモーラーレベルの亜鉛(II)イオンの計測

佐藤生男・亀山雅之・有賀貴子・飯田泰広

神奈川工科大学・応用化学科

BIOSENSING OF ZINC(II) IONS AT FEMTOMOLAR LEVELS BASED ON AN APOENZYME REACTIVATION METHOD

Ikuo SATOH, Masayuki KAMEYAMA, Takako ARIGA, and Yasuhiro IIDA

Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute of Technology
1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken, 243-0292, Japan

Ultrasensitive method for detecting heavy metal ions was demonstrated by using an apoenzyme reactivation method. Alkaline phosphatase immobilized onto porous glass beads was packed into a small polymer column and then used as a recognition element for zinc(II) ions in flow streams. The biosensing system was assembled with a small column containing the immobilized preparations mounted in a water-jacketed holder and a flow injection photometric device. The catalytic activity was assessed by injecting 0.1 ml of 2 mM p-nitrophenyl phosphate (pH 8.0). The column could be regenerated by introducing 100 mM 2,6-pyridine dicarboxylate solution to remove zinc(II) ions complexed in the active site of the enzyme molecules. Zinc(II) ions in femtomolar levels were photometrically determined through its reactivation of the apoenzyme, i.e., metal-free enzyme. Performance of the system was examined.

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12.

トリエチルアンモニウム電極を用いた細胞内外pH差の測定

岡山大・薬、北海道大・院・薬*

勝 　孝、中川幸毅、金盛竜朗*、加茂直樹*、土屋友房

NEW METHODOLOGY FOR DETERMINING THE pH DIFFERENCE ACROSS A CELL MEMBRANE USING A TRIETHYLAMMONIUM-SENSITIVE MEMBRANE ELECTRODE

Takashi KATSU, Hideki NAKAGAWA, Tatsuaki KANAMORI*, Naoki KAMO*, and Tomofusa TSUCHIYA

Faculty of Pharmaceutical Sciences, Okayama University
Tsushima, Okayama 700-8530, Japan
*Graduate School of Pharmaceutical Sciences, Hokkaido University
Sapporo, 060-0812, Japan, Japan

We constructed a triethylammonium-sensitive membrane electrode using sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate as an ion-exchanger and benzyl 2-nitrophenyl ether as a solvent mediator in a poly(vinyl chloride) membrane matrix and applied it for the determination of the pH difference across a cell membrane. The method is based on monitoring of the pH gradient-induced uptake of triethylammonium in situ. In experiments using liposomes, the uptake of triethylammonium into liposomes was quantitatively induced according to the pH difference across the liposomal membrane. The transmembrane pH difference in Escherichia coli cells and the light-induced formation of the pH difference across the envelope vesicles of Halobacterium halobium were successfully determined by the present method.

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13.

新しいMolecular Imprinting手法に基づくイオンセンサの開発

Bhavana A. Deore, 長岡　勉

山口大工

A NOVEL MOLECULAR IMPRINTING TECHNOLOGY FOR RECOGNITION OF IONIC COMPOUNDS

Bhavana A. DEORE, and Tsutomu NAGAOKA

Division of Applied Chemistry, Graduate School of Science and Engineering, Yamaguchi University
2-16-1 Tokiwadai, Ube 755-8611, Japan

Overoxidized polypyrrole films templated with L-glutamate have been utilized for enantiomeric separation of L- and D-glutamic acid. Various important fabrication factors controlling the performance of the overoxidized polypyrrole films have been investigated using fluorescence spectrometry in conjugation with the electrochemical quartz crystal microbalance technique. The measured fluorescence intensity was related to the concentration of glutamate taken up into the films. It was found that L-glutamate was inserted 10 times as much into the film as D-glutamate. Several key parameters such as applied potential, and pH of amino acid solution were varied so as to achieve the optimum sensor response.

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14.

酸化物薄膜系エレクトロクロミックデバイスによるリン酸イオンセンシング

塩塚政行、高瀬聡子、清水陽一

九工大工

ELECTROCHROMIC HYDROGEN-PHOSPHATE ION SENSOR USING SPINEL-TYPE METAL-OXIDE T HIN-FILM

Masayuki SHIOTSUKA, Satoko TAKASE, and Youichi SHIMIZU*

Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology
1-1 Sensui-cho, Tobata, Kitakyushu 804-8550, Japan

High-sensitive hydrogen-phosphate ion sensor based on electrochromism of spi nel-type oxide thin-film electrode was developed. Among the oxide thin-film s tested, a MnCo2O4 thin-film electrode showed a remarkable change of absor bance at 400-800 nm, under applying anodic potential at +0.8V vs. Ag/AgCl, w hich was depending on HPO42- concentration. The change of the absorbance at 500 nm, the sensor signal, was almost linear to the logarithm of the HPO42- concentration between 1.0×10-6 and 1.0×10-2M. The 90% response time, whe n the electrode potential was changed from +0.8 V to 0 V vs. Ag/AgCl at 1.0 ×10-2 M, was about 40s at room temperature. The MnCo2O4-based opto-electro chemical sensor hardly responded to NO3-, Cl- or SO42- at the sensing condi tion.

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15.

薬物代謝機能を利用したにおいセンサに関する研究

橋本祐樹、三林浩二

東海大工

STUDY OF A BIOELECTRONIC NOSE WITH A DRUG METABOLIZING SYSTEM

Yuki HASHIMOTO and Kohji MITSUBAYASHI

Department of Electrical Engineering, School of Engineering, TOKAI University
1117 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292, Japan

A biosensor and a bioelectronic nose for trimethylamine (TMA) in the liquid- and gas- phases were constructed using a flavin-containing monooxygenase 3 (FMO3) and a substrate regeneration cycle with reducing agents, respectively. The TMA biosensor in the liquid phase was calibrated against TMA solutions from 0.17 to 3.07 mmol/l, covering the concentration range encountered in the corrupt fish-flesh. The TMA bioelectronic nose using a reaction cell with both gas- and liquid-phase compartments could be used to continuous measure TMA vapor with high selectivity from 0.5 to 105 ppm, covering the maximum permitted concentration as defined by ACGIH.

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16.

金属電極を用いたチッソ酸化物の電気化学応答

谷口　功、宅島健次、古賀哲舟、稲田和文

熊本大工

ELECTROCHEMICAL RESPONSE OF NOx BY USING METAL ELECTRODES

Isao TANIGUCHI, Kenji TAKUSHIMA, Tessyu KOGA and Kazufumi INADA

Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University
2-39-1, Kurokami, Kumamoto 860-8555, Japan

Au, Cu, Pt and Ni electrodes have been investigated for detection of NOx. Cathodic peak was observed at ca. -0.5 and ca. -0.6 V vs. Ag/AgCl on Pt and Ni electrodes, respectibely, when nitrite was added to the solution. A Pt coated glassy carbon electrode gave clear reduction peak when 1 μM nitrite was added to the solution, while no response was observed on Au and Cu electrode for nitrite. Interstingly, on Cu electrode, cathodic peak current was observed at ca. -0.5 V due to nitric oxide reduction.

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17.

ポリジメチルシロキサン被覆電極によるNOの測定－生体試料への応用の可能性－

水谷文雄、平田芳樹、澤口隆博、矢吹聡一

生命工研

AMPEROMETRIC DETERMINATION OF NO (NITRIC OXIDE) USING AN ELECTRODE COATED WITH POLYDIMETHYLSILOXANE -THE POSSIBLE APPLICATION OF THE ELECTRODE TO MONITORING NO IN BIOLOGICAL SYSTEMS-

Fumio MIZUTANI, Yoshiki HIRATA, Takahiro SAWAGUCHI and Soichi YABUKI

National Institute of Bioscience and Human-Technology
1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan

Dip-coating of a platinum electrode from an aqueous dispersion of polydimethylsiloxane provided an amperometric nitric oxide (NO) sensor with high performance characteristics. The electrode gave rapid response (100% response time, 3 s), high sensitivity (detection limit, 20 nM), high stability (usable for more than a month) and high selectivity (e.g., the ratio of response for uric acid to that for the same concentration of NO, less than 10-4).

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18.

Iron / polyion complex被覆電極の特性と細胞NOセンシング

春山哲也＊、飯島誠一郎＊＊、相澤益男＊

東工大・院 生命情報＊、工技院生命研＊＊

CELLULAR NO SENSING USING IRON / POLYION COMPLEX COATED ELECTRODE

Tetsuya HARUYAMA*, Seiichiro IIJIMA** and Masuo AIZAWA*

*Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology
Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
**National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology
Higashi, Tsukuba, Ibaraki 305-8566, Japan

Nitric oxide (NO) is enzymatically synthesized from arginine in mammalian cells, and functions as a molecular messenger in various living systems. NO may therefore work as a probe in some cellular responses. For example, endothelial cells regulated NO production in response to chemical and physical vasodilatation factors. The cellular response may be evaluated by in situ NO monitoring. Although the authors have developed electrochemical NO sensors with various NO affinity sensor materials, a higher selectivity is required in cellular sensing. In this study, the authors employed a Iron / polyioncomplex as the sensor material. The authors found that the Fe2+ coordinated NO could be oxidized on an electrode at about 0 mV vs. Ag/AgCl. The iron-poly histidine / poly styrene complex is employed as a sensor material for electrochemical NO sensing. The sensor determines NO in the concentration range from 5 nM to 50μM in buffer solution when the potential is set at 0 mV vs. AgAgCl. As the NO sensing can be performed with very low potential application, endothelial cells can be cultured on a sensor device surface. The sensor output showed a NO production profile that was induced by vasodilator chemicals.

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19.

環境モニタリング用マイクロ電気泳動チップ(IV):有機汚染のハイスループットスクリーニングの予備的検討

脇田慎一、竹田さほり、千葉篤志*、福士惠一**、中西博昭***、松田十四夫*

大工研、立命館大理工*、神戸商船大**、島津製作所***

MICRO CHIP BASED CAPILLARY ELECTROPHORESIS FOR ENVIRONMENTAL MONITORING (IV): PRELIMINARY STUDY ON HIGH THROUGHPUT SCREENING FOR ORGANIC POLLUTION

Shin-ichi WAKIDA, Sahori TAKEDA, Atsushi CHIBA*, Keiichi FUKUSHI**, Hiroaki NAKANISHI*** and Toshio MATSUDA*

Department of Energy and the Environment, Osaka National Research Institute, AIST
Ikeda, Osaka 563-8577, Japan
*Department of Chemistry, Faculty of Science and Technology, Ritsumeikan University
Kusatsu, Shiga 525-8577, Japan
**Research Institute for Marine Cargo Transportation, Kobe Univ. of Mercantile Marine
Higashinada, Kobe 658-0022, Japan
***Technology Research Laboratory, Shimadzu Corp.
Soraku, Kyoto 619-0237, Japan

We preliminarily studied high throughput screening (HTS) for organic pollution in waters using microchip based capillary electrophoresis with laser-induced fluorescence (LIF) detection. The applied voltage was investigated to control the gated-valve injection and separation using self-made PC based controller for voltage supply. We obtained much improved HTS data for the reproducible separation of fluoresceinisothiocyanate (FITC) labeled river-water samples using zwitter-ion based buffer solution (Tris-CHES) to avoid the adsorption of the labeled sample to the channel of microchip. We applied the HTS for the real samples of Hino River, which flows in Lake Biwa, at the ten sampling points and obtained the reproducible several peaks for each sample within 2 min.

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20.

微小センシングモジュールによる血液ガスの測定

鈴木博章、平川大志、星　拓男*、豊岡秀訓*

筑波大物質工、筑波大臨床医*

DETERMINATION OF BLOOD GAS LEVELS USING A MINIATURIZED SENSING MODULE

Hiroaki SUZUKI, Taishi HIRAKAWA, Takuo Hoshi, and Hidenori TOYOOKA

Institute of Materials Science, University of Tsukuba,
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
Institute of Clinical Medicine, University of Tsukuba
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan

A sensing module for blood gasses was used to measure pO2, pCO2 and pH levels in human whole blood. In order to examine the effect of oxygen consumption, oxygen electrodes with cathodes of different dimensions were prepared and their performance was compared. Flow dependence was reduced to 1～3% by using a cathode of 25 mm × 25 mm. Also, the lifetime of the on-chip reference electrode was elongated to approximately 18 h by modifying the structure of the liquid junction. The pO2, pCO2 and pH values were measured using the sensing module and a commercial blood gas analyser and were compared. Deviation of the pH and pO2 values was 0.06 pH unit and 15 mmHg for the worst case respectively. On the other hand, a substantial deviation was observed with the pCO2 values.

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21.

インテリジェントモスキート（１）

小林邦幸、鈴木博章

筑波大物質工

INTELLIGENT MOSQUITO (1)

Kuniyuki KOBAYASHI and Hiroaki SUZUKI

Institute of Materials Science, University of Tsukuba
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan

Realization of a miniaturized analysis system imitating a mosquito has been a long-standing dream in clinical diagnosis. Once it is realized, sampling of blood and following analysis can be conducted without any physical pain. In constructing such a mosquito, three of the most essential components will be 1) microsensors, 2) a sampling mechanism, and 3) a microneedle. The sampling mechanism has been constructed employing the phase transition of poly(n-isopropylacrylamide) gel, which functions in response to the change in temperature. The microneedle was formed by electroplating platinum on an Al-1% Si wire and dissolving the wire. The sampling mechanism and the microneedle were incorporated in a micro analysis system which had a micro glucose sensor. After the gel was shrunk at 40℃making contact with a buffer solution, the inlet of the sampling mechanism was made in contact with a sample solution at 30℃. A current increase was observed following the sampling. The 90% response time was from 1 min to 4 min. A linear calibration curve was obtained for glucose concentrations less than 5 mM.

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22.

電気化学的手法を用いたキャピラリーフロー型検出システムの作製

林　泰圭、今井郷子、竹山春子、松永　是

東京農工大工

CONSTRUCTION OF ELECTROCHEMICAL FLOW IMMUNOASSAY SYSTEM USING CAPILLARY COLUMNS

Tae-Kyu LIM, Satoko IMAI, Haruko TAKEYAMA, Tadashi MATSUNAGA

Department of Biotechnology, Tokyo University of Agriculture and Technology
Koganei, Tokyo 184-8588, Japan

Ferrocenecarboxylic acid (Fc) conjugated with anti-HCG immunoglobulin G (IgG) antibody (Fc-IgG) was prepared and used as a novel analytical reagent. The system consists of the immunoreaction part, the capillary column packed with cation exchange resin, and the flow cell for electrochemical detection of Fc-IgG. The assay yielded a linear relationship between signal and HCG concentration in the range of 0 - 2000 mIU/mL. This simple technique permits the assay of HCG within 2 min. This electrochemical flow immunoassay requires minute quantities of serum and generates highly reproducible results.

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23.

ヘテロコア型光ファイバセンサの化学センサへの応用に関する基礎研究

平間恭子, *関篤志，渡辺一弘

創価大学工

APPLICATIONS OF A HETERO-CORE FIBER OPTIC SENSOR TO CHEMICAL SUBSTANCE DETECTION

Kyouko HIRAMA, *Atsushi SEKI, Kazuhiro WATANABE

Dept. of Information Systems Science. *Dept. of Bioengineering, Faculty of Engineering,SOKA University
Hachiouji-shi,Tokyo 192-8577, Japan

A new type of fiber optic sensor has been developed for liquid detection. This sensor makes possible an interaction between confined optical signals in an optical fiber and liquid adhesion around outer cladding region because of its novel hetero-core splicing structure. The sensor utilizes a short-length, different core-size fiber insertion in a multi-mode-fiber as a transmission line. The results obtained in the experiments show that the hetero-core fiber optic would be applied to chemical sensors for liquid detection and acid concentration.

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24.

pH応答を利用した電流検出型NH3,CO2ガスセンサの反応機構解析

今屋浩志、石地 徹

理研計器

DETECTION MECHANISM OF AMPEROMETRIC SENSOR BASED ON pH-DEPENDENT REDOX REACTION OF METAL OXIDE FOR NH3 AND CO2

Hiroshi IMAYA and Toru ISHIJI

Riken Keiki Co., Ltd.
2-7-6 Azusawa Itabashi-ku, Tokyo 174-8744, Japan

An amperometric sensor based on pH dependent redox reaction of RuO2 electrode for the detection of NH3 and CO2 gases has been developed. The sensor shows good characteristics of the response and stability for the sensing. The detection mechanisms of the sensing reactions were studied by using different pH solutions and buffer solutions. The oxidation and reduction mechanisms induced by NH3 and CO2, respectively, were explained by pH dependent electrode reactions.

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25.

安定化ジルコニアとSnO2系電極を組み合わせた混成電位型N2Oセンサ

釘島裕洋、金沢英一、島ノ江憲剛、上村裕一＊、寺岡靖剛＊＊、三浦則雄＊＊＊、 山添　曻

九大院総理工、鹿児島大医＊、長崎大工＊＊、九大先端センター＊＊＊

MIXED-POTENTIAL TYPE SENSOR BASED ON STABILIZED ZIRCONIA AND SnO2 ELEC TRODE FOR DETECTION OF N2O

Masahiro KUGISHIMA, Eiichi KANAZAWA, Kengo SHIMANOE, Yuichi KANMURA ＊, Yasutake TERAOKA＊＊, Norio MIURA＊＊＊, and Noboru YAMAZOE

Department of Molecular and Material Sciences, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan
＊Faculty of Medicine, Kagoshima University
Sakuragaoka, Kagoshima 890-8520, Japan
＊＊Faculty of Engineering , Nagasaki University
Bunkyo-machi, Nagasaki 852-8521, Japan
＊＊＊Advanced Science and Technology Center for Cooperative Research, Kyushu University
Kasuga-shi, Fukuoka 816-8580

A stabilized-zirconia based electrochemical device attached with oxide electrode was developed for the detection of N2O. Among the eleven kinds of oxides tested, SnO2 was found to be best suited for the sensing electrode of a tubular zirconia device, giving relatively high sensitivity to N2O in air at 475℃. The EMF value of the device was almost linear to the logarithm of N2O concentration in the range of 50-200 ppm. The addition of foreign oxides (e.g. Bi2O3, SrO, CaO, Pr6O11, Nd2O3, Sm2O3) to SnO2 was effective for improving the N2O sensitivity. Especially the element using 0.5wt%Sm2O3-SnO2 electrode exhibited the N2O sensitivity about 1.5 times as high as that of pure SnO2 element. Furthermore, a compact planar device was fabricated. The lower detection limit of the device was found about 35 ppm. A sensing mechanism involving mixed potential was confirmed based on the mesurments of polarization curves.

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26.

酸化物電極を用いた混成電位式ＮＯxセンサの検知性能

小野 敬、長谷井政治、厳　永鉄、高　云智、三浦　則雄＊、国元 晃

株式会社リケン、＊九州大学先端研

SENSING PERFORMANCE ON THE MIXED POTENTIAL TYPE NOx SENSOR USING OXIDE ELECTRODE

Takashi ONO, Masaharu HASEI, Yongtie YAN, Yunzhi GAO, Norio MIURA*, and Akira KUNIMOTO

R & D Division, Riken Corporation
Kumagaya-shi, Saitama 360-8522, Japan
*Advanced Science and Technology Center for Cooperative Reserch, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan

The NOx Sensor based on Mixed Potential was made by laminating YSZ green sheets, on which electrodes including an NOx sensing electrode consisting of metal-oxide (NiCr2O4), an NOx conversion electrode, a Pt heater and a pair of thermocouples were printed and sintered. The sensor was greatly capable of detecting low concentrations of converted NO2 as a total-NOx concentration. Interference from HC, CO and H2O was comparatively small, and fairly independent on oxygen concentration.

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特別講演

協奏反応場での特異化学ポテンシャルの解明とガスセンシングへの展開

◯水崎　純一郎、八代　圭司，川田　達也

東北大科研

CHEMICAL POTENTIAL ANOMALY AT CONCERTED REACTION SITES AND ITS APPLICATION TO GAS SENSING

Junichiro MIZUSAKI, Keiji YASHIRO, and Tatsuya KAWADA

Research Institute for Scientific Measurements, Tohoku University
2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan

Discussion is made on the concerted reactions at the electrochemical interface of potentiometric zirconia sensors and at the surface of mixed-conductor sensors involving gas and solid phases in the electrochemical or chemical potential field. The response rate of potentiometric sensors is determined by the electrode properties. The EMF is determined by the oxygen chemical potential at the zirconia / electrode interface and its relaxation process accompanies the gas electrode reaction at the triple phase boundary of zirconia / electrode /gas. The EMF of zirconia sensor in nonequilibrium gas mixtures of O2, CO and H2 is not determined by a simple mixed-potential theory. A mechanism of the cross effect between CO and H2 is discussed. Small amount of NO2 in O2 rich atmospheres causes variations in conductivity and oxygen nonstoichiometry of oxide mixed-conductors. The decomposition of NO2 on the oxide surface enhances the surface oxygen potential and the bulk of oxide is equilibrated to the surface.

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27.

小型・低消費電力固体電解質型ＣＯ2センサの開発

フィガロ技研・トクヤマ*

真鍋太祐、兼安一成、中原毅、佐井正和*、池谷拓速*、山本信幸*、松井光彦*

DEVELOPMENT OF CO2 GAS SENSOR WITH LOW POWER CONSUMPTION AND COMPACT SIZE

Taisuke MANABE, Kazunari KANEYASU, Takeshi NAKAHARA, Masakazu SAI*, Hirotoshi IKEYA*, Nobuyuki YAMAMOTO* and Mitsuhiko MATSUI*

FIGARO Engineering Inc.
1-5-11 Senbanishi, Mino-city, Osaka 562-8505, Japan

Solid-state electrochemical sensor device with sodium super ionic conductor (NASICON:Na3Zr2Si2PO12) chip was fabricated on alumina substrate with RuO2 heater. We have developed a new solid electrolyte type sensor which offers miniaturization and low power consumption. The power consumption to maintain the device temperature of 450℃ was about 250mW. The EMF (Electromotive force) was linear to the logarithm of CO2 concentration and hardly depended on interfering gases. The sensor shows excellent CO2 sensing properties.

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28.

Liイオン伝導体を用いた固体電解質型CO2センサの開発

〇張　益燦1、　金子　稔1、木村　滋行1、荻原　長雄1、内田　清1、水崎　純一郎2、田川　博章3、井上　邦弘4、　濱田　友孝4

曙ブレーキ中研1、　東北大科研2、　横浜国大学環境研3、科学技術振興事業団4

DEVELOPMENT OF SOLID ELECTROLYTE CO2 SENSOR USING LI-ION CONDUCTORS

Y. C. ZHANG1, M. KANEKO1, S. KIMURA1, O. OGIWARA1, K. UCHIDA1,　J. MIZUSAKI2, H. TAGAWA3, K. INOUE4, and T. HAMADA4

1Akebono R/D Center,LTD. Hanyu, Saitama 348-8501, Japan
2Research Institute for Scientific Measurements, Tohuku University, Sendai 980-8577, Japan
3Institute of Environmental Science and Technology, Yokohama National University, Yokohama 240, Japan
4Japan Science and Technology Corporation, Tokyo 102-0081, Japan

Solid electrolyte CO2 sensors comprising Au+Li2CO3∥Li-ion conducting glass-ceramics(Ohara Inc.) ∥LiFeO2-LiFe5O8+Au have been developed, where Li2CO3 works as a lithium-ion solid electrolyte and a sensing electrode material, and the two phase mixture LiFeO2-LiFe5O8 is used as the reference electrode material. Electromotive force (EMF) of the sensor depend logarithmically on the CO2 partial pressure in CO2/O2 gas mixtures at temperatures above 450℃ while it is independent of the O2 partial pressure. The EMF of the sensors were reproducible within ±3mV　on a continuous operation for more than 340 days at 95%RH. This result shows that the developed CO2 sensors have high humidity-resistance and good stability. The sensing mechanism of CO2 was also discussed.

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29.

水素の電解排出を利用した起電力式高温水素センサ

片平幸司、松本広重、岩原弘育、岩元孝史*

名大理工総研, 株式会社TYK*

HIGH TEMPERATURE GALVANIC CELL TYPE HYDROGEN SENSOR WITH ELECTROCHEMICAL HYDRO GEN EVACUATION

Koji KATAHIRA, Hiroshige MATSUMOTO, Hiroyasu IWAHARA, and Takashi IWAMOTO *

Center for Integrated Research in Science and Engineering, Nagoya University
Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan
*TYK Corporation, Advanced Materials Research & Development Center
3-1, Ohbat a-cho, Tajimi, 507-8607, Japan

Galvanic cell type high temperature hydrogen sensor with electrochemical hydro gen evacuation was constructed using a proton conducting CaZr0.9In0.1O3-α cera mic as a solid electrolyte. The sensor consists of two electrochemical cells which contact tightly with each other. One cell with constant voltage is for a hydrogen pump to decrease hydrogen activity in the contact interface and the other cell is for a sensing of hydrogen activity in the test gas, based on th e hydrogen at the contact interface. EMF of the sensor showed good response t o hydrogen at elevated temperature with pumping currents as little as a few mA . In addition to the hydrogen sensing, this sensor can also work as the steam sensor.

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30.

Na+導電体を用いた電流検出型 NO2 センサのクロノポテンシオメトリー法による検知極反応解析

小野正樹、島ノ江憲剛、三浦則雄*、山添　曻

九大院総理工、九大先端センター*

ANALYSIS ON SENSING ELECTRODE REACTIONS OF AMPEROMETRIC NO2 SENSOR BASED ON Na+ CONDUCTOR BY USING CHRONOPOTENTIOMETRY

Masaki ONO, Kengo SHIMANOE, Norio MIURA* and Noboru YAMAZOE

Department of Molecular and Material Sciences, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan
*Advanced Science and Technology Center for Cooperative Research, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan

Galvanostatic chronopotentiometry was performed to identify the reaction products formed on the sensing electrode for an amperometric NO2 sensor based on NASICON (Na+ conductor). The products after the NO2 sensing operation at 150。C were confirmed to be NaNO2 and NaNO3. The amount of NaNO2 (and NaNO3) formed increased with increasing sensor operating time in the NO2-containing air. On the other hand, NaOx (presumably Na2O2) was formed on the sensing electrode through the cathodic reaction of O2. To clarify the mechanism of NaNO3 formation, the sensor was subjected to treatments under various conditon. Consequently, it is concluded that NaNO2 is formed as a primary product of the cathodic reaction of NO2, while NaNO3 is formed as a secondary product of the chemical reaction between NaOx and NaNO2 under the dry condition.

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31.

超高周波水晶振動子を用いたガスセンサーに関する研究

黒澤　茂、田知行　大輔1、韓　大相、愛澤　秀信、吉本　稔1

物質研、鹿児島大院理工1

STUDY TO INCREASE THE SENSITIVITY OF QCM GAS-SENSOR COATED WITH PLASMA POLYM ERIZATION FILM

Shigeru KUROSAWA, Daisuke TACHIYUKI, Dae-Sang HAN, Hidenobu AIZAWA, Minoru Y OSHIMOTO

National Institute of Materials and Chemical Research
1-1 Higashi，Tsukuba，Ibaraki 305-8565, Japan

Fundamental and overtone modes of quartz resonators with high frequencies ha ve been studied to increase the sensitivity of QCM gas-sensor. Polystyrene f ilm was plasma-polymerized onto the electrode surface of an AT-cut quartz re sonator and then used as a molecular recognition membrane to detect gas-phas e analytes. In this study, handmade oscillators with superior stability were used to vibrate each mode of AT-cut quartz resonators. Deriving the theoret ical mass sensitivity of an AT-cut quartz resonator vibrating at the overton e mode, confirmed the fact that the theoretical value was the same as the re sult obtained from the experiments.

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32.

フラーレン膜を用いたガスセンサ

香田弘史、中島広哉、櫻井芳昭*、岡本昭夫*、野坂俊紀*

エフアイエス、大阪産技総研*

GAS SENSOR USING FULLERENE FILM

Hiroshi KODA, Hiroya NAKAJIMA, Yoshiaki SAKURAI*, Akio OKAMOTO*, and Toshikazu NOSAKA*

FiS Inc.
3-36-3 Kitazono, Itami, Hyogo 664-0891, Japan
*Technology Resarch Insitute of Osaka Prefecture
2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan

It is known that‘fullerene' is a carbon isotope which has a soccer ball crystal structure, and that fullerene adsorb polarized gases such as ammonia, nitrogen oxides selectively but not non polarized gases such as methane, CO and hydrogen. We have studied the gas sensing characteristics of fullerene with the following two methods. 1) measuring the electric conductivity changes of a fullerene film formed on an alumina substrate, 2) using the frequency modulation of a fullerene film formed on the surface of quartz crystal oscillator. In both cases, the signals from fullerene showed a reversible and fast response with the gas concentration changes. This result suggests that there is a possibility of developing a new gas sensor which works at room temperature. Using this feature, the most simple and low cost solid state gas sensor requiring no complicated heating system can be realised.

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33.

縮合多環炭化水素の蛍光消光現象を利用した酸素センサ

安部隆志、松口正信、酒井義郎

愛媛大工

OPTICAL OXYGEN SENSOR BASED ON FLUORESCENCE QUENCHING OF POLYCYCLIC AROMATIC HYDROCARBONS

Takashi ABE, Masanobu MATSUGUCHI, and Yoshiro SAKAI

Department of Applied Chemistry, Faculty of Engineering, Ehime University
3 Bunkyo, Matsuyama, Ehime 790-8577, Japan

Various blended films were prepared by the combination of eight kinds of polycyclic aromatic hydrocarbons and thirteen kinds of polymers for the use of fluorescence quenching oxygen sensors. The fluorescence quenching of these sensors by oxygen obeys Stern-Volmer equation. The sensor, which was prepared by the combination of organically modified polysiloxane and 1-pyrenebutyric acid, shows the highest sensitivity, the shortest response time, and good reproducibility among the prepared sensing films.

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34.

高分子複合膜CO2センサにおける共存ガスによる影響

椎木　弘，大穂隆博，外崎　剛，中山雅晴，小倉興太郎

山口大工

EFFECT OF VARIOUS GASES ON THE RESPONSE OF POLYMER COMPOSITE TO CO2 GAS

Hiroshi SHIIGI, Takahiro OHO, Tsuyoshi TONOSAKI, Masaharu NAKAYAMA and Kotaro OGURA

Faculty of Engineering, Department of Applied Chemistry, Yamaguchi University
Tokiwadai, Ube 755-8611, Japan

The composite film consisting of base-type polyaniline (PAn) and poly(vinyl alcohol) (PVA) responds to CO2 at room temperature, and the electrical resistance is linearly related with CO2 concentration in a wide range from 50 ppm to 10 %. The decrease in resistance of the composite film in proportion to the CO2 concentration is attributed to the transformation of the base-type PAn to the salt-type, which is caused by the incorporation of carbonate ions formed by the hydrolysis of CO2 into the base type-PAn. In the present report, the effects of various gases including N2O, O2, alcohol, HCl and NH3 on the response of the composite film to CO2 gas have been investigated.

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35.

表面修飾されたSnO2系ガスセンサのCOガス感度と経時安定性および温湿度依存性との関係

盛満正嗣、尾崎康隆*、鈴木祥代*、松永守央

九州工業大学工学部・フィガロ技研*

CO SENSITIVITY OF SURFACE MODIFIED SnO2-BASED GAS SENSORS AND ITS RELATIONSHIP TO LONG-TERM STABILITY AND TEMPERATURE-HUMIDITY DEPENDENCE

Masatsugu MORIMITSU, Yasutaka OZAKI*, Sachiyo SUZUKI*, and Morio MATSUNAGA

Department of Applied Chemistry, Kyushu Institute of Technology
Tobata, Kitakyushu 804-8550, Japan
*Figaro Engineering Inc.
Minoo, Osaka 562-8505, Japan

The long-term stability and temperature-humidity dependence of SnO2-based CO gas sensors modified with sulfuric acid, thiourea, and platinum group metals were discussed in regard to their relationships to the sensitivity to CO. The resistance change with temperature and humidity was highly dependent of the CO sensitivity; the resistance change at varied temperature and humidity conditions was more reduced with increasing sensitivity for the modified sensors. A major dependency of the long-term stability of the sensor resistance on the CO sensitivity was not confirmed. The effects of the surface modifications on the sensor resistances in CO and air, governing the CO sensitivity, were also argued.

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36.

半導体ガスセンサ基板の多孔質化

〇川原昭彦、勝木宏昭、江頭　誠*

佐賀県窯業技術センター・長崎大工*

EMPLOYMENT OF POROUS CERAMICS AS THE SUBSTRATES OF SEMICONDUCTOR GAS SENSORS

Akihiko KAWAHARA, Hiroaki KATSUKI, and Makoto EGASHIRA*

Fine Ceramic Division, Saga Ceramics Research Laboratory
Arita-machi, Nishimatsuura-gun, Saga 844-0024, Japan
* Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan

Porous needle-like mullite and porous alumina ceramics were employed as the substrates of semiconductor gas sensors. Gas-sensing characteristics to n-C4H10 and NOx of thick film sensors using the porous substrates were investigated. A sensor in which a SnO2 layer was prepared on a porous mullite layer showed the maximum sensitivity of S=6.3 to 425 ppm n-C4H10 at 550℃. Another sensor, fabricated by stacking slide-off transfer sheets of porous alumina, Pt electrode and SnO2 layers in a pile on a dense alumina substrate, showed the maximum sensitivity of S=186 to 88 ppm NO2 at 300℃. In this sensor, the porous alumina layer had a porosity 56.2%. The sensors using porous substrates thus showed high sensitivity compared with the sensors fabricated directly on dense substrates. The variations in the gas-sensing properties have been discussed in terms of the conduction pass of the thick films and the permeation properties of the related gases.

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37.

転写印刷法によるヘテロ積層型NOxセンサの開発

兵頭健生、冨永義明、山口　崇、川原昭彦*、勝木宏昭*、清水康博、江頭　誠

長崎大工、佐賀県窯技センター*

DEVELOPMENT OF HETEROLAYER NOx SENSORS BY SLIDE-OFF TRANSFER PRINTING

Takeo Hyodo, Yoshiaki Tominaga, Takashi Yamaguchi, Akihiko Kawahara, Hiroaki Katsuki, Yasuhiro Shimizu, Makoto Egashira

Department of Materials Science & Engineering, Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan

NOx sensing properties of semiconductor heterolayer sensors fabricated by slide-off transfer printing were investigated. A WO3 single layer sensor showed much higher sensitivity to NO2 than that to NO. Loading of Ru or Pt on pure WO3 led to slight improvement of both the sensitivity and the response speed to NO, but the response speed to NO2 was decreased especially by the Ru loading. In contrast, loading of Au largely improved the sensitivity and the response speed to both NO2 and NO. The stacking of an 0.5Pt-Al2O3 layer over the Au-WO3 layer showed little effect on the NOx sensitivities, whereas double or triple stacking resulted in a remarkable enhancement of NOx sensitivities at 350℃. On the other hand, the NO2 sensitivity of WO3-based heterolayer sensors decreased with an increase in the loading amount of Pt in the Pt-Al2O3 stacking layer, while the NO sensitivity increased. Especially, it was found that the 1.0Pt-Al2O3/WO3 heterolayer sensor exhibited comparable sensitivity to both NO2 and NO at 350℃.

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38.

ナノホールを有する陽極酸化膜の水素ガス検出特性

桑野直樹、兵頭健生、清水康博、江頭　誠

長崎大工

H2 GAS SENSING PROPERTIES OF AN ANODICALLY OXIDIZED FILM WITH NANOHOLES

Naoki KUWANO, Takeo HYODO, Yasuhiro SHIMIZU and Makoto EGASHIRA

Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan

H2 sensing properties of TiO2 films prepared by air oxidation and anodic oxidation of Ti metal have been investigated at 250 - 500°C. Both the film sensors showed apparently little sensitivity to 1.0% H2 in air under forward bias voltage in the whole temperature range studied, but showed high sensitivity at temperatures lower than 400°C under reverse bias voltage. The sensitivity of the anodically oxidized TiO2 sensor (A-TiO2) was much superior to the air oxidized TiO2 sensor (R-TiO2). The A-TiO2 sensor also showed certain sensitivity to H2 balanced with N2 even at a temperature of 500°C under reverse bias voltage, and the sensor resistance recovered quickly to the original N2 level after removal of H2. These results implied that the sensitivity was due to the change in work function of Pd induced by the dissolution of atomic hydrogen into Pd, in addition to that induced by the consumption of oxygen adsorbates on Pd by the reaction with H2. The current-voltage characteristics of the A-TiO2 sensor in both air and 1.0% H2 revealed that the sensor was also a diode type H2 sensor.

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39.

単一の半導体ガスセンサを用いた混在ガスの識別・定量

◯加藤　陽、加藤喜美子、瀬戸口泰弘、中原　毅

フィガロ技研株式会社

DISCRIMINATION AND QUANTIFICATION OF MIXED GASES BY A SINGLE SEMICONDUCTOR GAS SENSOR

Yo KATO, Kimiko KATO, Yasuhiro SETOGUCHI, Takeshi NAKAHARA

Figaro Engineering Inc.
Senbanishi 1-5-11, Mino, Osaka 562-8505, Japan

We propose a method of discrimination and quantification of mixed gases by a single semiconductor gas sensor, based on the information embedded in a nonlinear dynamic response. By applying a sinusoidal voltage to a heater attached to SnO2, a characteristic time-dependent trace of the sensor resistance is obtained as a response to environmental gases. In order to evaluate the characteristic response in a quantitative manner, Fast Fourier Transform (FFT) is performed for the dynamic response. Higher harmonics, obtained by performing the FFT, were processed using a　discrimination method and a multiple regression. For instance, we show that mixture of ethanol and carbon monoxide (CO) gases can be identified both components and also be quantified.

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40.

酸化スズ系ガスセンサを用いた悪臭ガスとしての脂肪族カルボン酸の検知

林　知範、玉置　純、山本善史、松岡政夫

立命館大理工

DETECTION OF ALIPHATIC CARBOXYLIC ACIDS AS OFFENSIVE ODORS USING TIN OXIDE BASED SENSORS

Tomonori HAYASHI, Jun TAMAKI, Yoshifumi YAMAMOTO, and Masao MATSUOKA

Department of Applied Chemistry, Faculty of Science and Engineering, Ritsumeikan University
Kusatsu-shi, Shiga 525-8577, Japan

Sensing properties to aliphatic carboxylic acids (C2～C8) have been investig ated using SnO2-based sensors in order to develop highly sensitive sensors to offensive odors. Among 18 kinds of modified SnO2 sensors tested, the addition of MoO3 or WO3 improved the sensitivities to aliphatic carboxylic acids. For the MoO3-SnO2 sensor, the sensitivity to C2～C8 carboxylic acid decreased with increasing carbon number. On the other hand, the WO3-SnO2 sensor showed the maximum sensitivity to butyric acid (C4) . These differences in sensing properties were related with the catalytic properties of sensing materials.

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41.

分解熱検知型高濃度オゾンセンサの特性評価

岡崎慎司，中川英元，朝倉祝治，清水博則*，岩本　勇*

横浜国大工・荏原実業（株）*

EVALUATION OF A NEW OZONE SENSOR USING COMBUSTION-TYPE GAS SENSOR DEVICES FOR AN OZONE GENERATOR

S.Okazaki, H.Nakagawa, S.Asakura, H.Shimizu, and I.Iwamoto

Department of Materials Science and Chemical Engineering, Yokohama National University
Tokiwadai 79-5 Hodogaya-ku, Yokohama 240-8501, Japan

A stable ozone sensor for quantitative analysis, targeted to be a monitor for an ozone generator, is proposed. The operation principle of the sensor is similar to that of a catalytic combustion sensor. The proposed sensor uses two thermal devices of physically and chemically identical characteristics. The first device, a detecting device, is operated well above the thermal decomposition temperature of ozone, whereas the second device, a reference device, is operated near room temperature to avoid thermal decomposition. The detecting device detects the ozone by temperature rise of ozone decomposition origin, and the reference device compensates ambient temperature drift. The reference signal is amplified with appropriate gain and is subtracted from the signal of the detecting device to form temperature-compensated output signal. The proposed sensor exhibited excellent sensing characteristics with good reproducibility and long-term stability. Effect of ambient temperature drift was suppressed almost completely. Other sensing characteristics, such as effect of source gas composition, humidity, and pressure is also discussed.

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42.

シリコン薄膜LAPSの検討

伊藤　善孝

新電元工業株式会社　研究開発センター

BEHAVIOR OF ULTRA-THIN LAYER LAPS

Yoshitaka Ito

Research & Development Center, Shindengen Kogyo
10-13 Minamicho, Hanno-shi, Saitama-ken, 357-8585, Japan

The thinner Si on transparent substrates will have the advantages over the thicker Si wafer sensor when we realize the high spatial resolution in pH imaging sensor system. The aim of this study is to provide a theoretical and practical basis for a Light-Addressable Potentiometric Sensor (LAPS) devices. The calculated absorption was the same profile as the measured spectral photo-current response. To compute the Finite Element Modeling (FEM) simulation the 2-D and 3-D models were proposed. FEM results showed a good resemblance with the measured data.

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