Abstracts

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気液反応を利用したマイクロ化学分析チップの基礎検討

マイクロ化学プロセス技術研究組合＊，東大院工＊＊

○八谷宏光＊，吉田佳一＊，北森武彦＊,＊＊

STUDY OF MICRO CHEMICAL ANALYSIS CHIP USING GAS-LIQUID REACTION

Hiromitsu HACHIYA＊, Yoshikazu YOSHIDA＊, Takehiko KITAMORI＊,＊＊

The Research Association of Micro Chemical Plant Technology＊
KSP-Bldg., 3-2-1, Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa, 213-0012, JAPAN
Department of Applied Chemistry, School of Engineering, The University of Tokyo＊＊
7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, JAPAN

The micro chemical analysis chip using gas-liquid reaction was studied. The micro chips that had 3-flow or 2-flow micro channels were tested their performances, for example the stability of gas-liquid interfaces. Both of 3-flow and 2-flow type chips showed the possibility for gas-liquid analysis. The response for ammonia gas was also examined. A standard thermal lens microscope (TLM) was used as a detector in this study. The good sensibility for ammonia gas in ppm level was observed.

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チャンバーアレイPCRによる複数種同時遺伝子検出法の開発

○松原泰孝、小林正昭、森田資隆、高村 禪、民谷栄一

北陸先端大院材料

DEVELOPMENT OF SILICON MICROCHAMBER ARRAY FOR MULTIPLE DNA AMPLIFICATION AND DETECTION

Yasutaka MATSUBARA, Masaaki KOBAYASHI, Yasutake MORITA, Yuzuru TAKAMURA and Eiichi TAMIYA

School of Materials Science, Japan Advanced Institute of Science and Technology
Tatsunokuchi, Ishikawa 923-1292, Japan

This paper describes on-chip DNA amplification in a highly integrated microchamber array. The 40 nL of PCR mixture was introduced into each chamber of the microarray precisely by using nL dispensing system through the oil layer that served as a converlid. The amplified DNA was then detected with CCD camera built-in fluorescence microscope by using SYBR Green and TaqMan chemistry. Three different target DNA samples were amplified and detected in the same microchamber array for the first time. Therefore, this system proves to be a promising divice for the low-cost high-throughput DNA amplification and detection for point-of-care clinical diagnosis, which can also be handled by non-specialist users.

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電気泳動および誘電泳動を利用したマイクロチャンネル内における微粒子の流動制御

東北大院環境・院工

○尾形幸子，安川智之，珠玖　仁，末永智一

ELECTROPHORETIC AND DIELECTROPHORETIC CONTROLE OF MICROPARTICLES IN THE MICROFLUIDIC CHANNEL

Sachiko OGATA, Tomoyuki YASUKAWA, Hitoshi SHIKU, Tomokazu MATSUE

Graduate School of Environmental Studies, Tohoku University, 07 Aoba,
Aramaki, Aoba, Sendai 980-8579, Japan

Electrophoretic manipulation of microparticles was performed using a microfluidic device with two electrodes. The structure of microfluidic device was fabricated using a positive photoresist and PDMS. The center part of the device contained two electrodes on both sides of the fluidic channel to generate an electrophoretic force. Microfluidic features included three inlet/outlet channels, respectively. Electrolyte solutions including microparticles were introduced from the center inlet. Particles flowing in the electrolyte solution with laminar and sheath flow, when arriving at the position near the electrodes, were immediately manipulated and captured at the electrode which was applied a positive potential by an electrophresis. After switching off, microparticles were withdrew to an edge outlet. Dielectrophoresis, the movement of particles in non-uniform ac electric field, has also been used to manipulate microparticles by using polynomial type electrodes and to decide the direction of movement by utilizing the difference in the distribution of an electric field.

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半導体化学イメージセンサによるマイクロ流路内のイオン濃度分布測定

阪大産研

○宇井靖人、吉信達夫、岩崎裕

LIGHT-ADDRESSABLE POTENTIOMETRIC SENSOR FOR DETECTION OF ION DISTRIBUTION IN MICRO FLUIDIC CHANNEL

Yasuhito UI, Tatsuo YOSHINOBU, Hiroshi IWASAKI

The Institute of Scientific and Industrial Research, Osaka University, 8-1
Mihogaoka, Ibaraki, Osaka 567-0047

Light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor with an electrolyte-insulator-semiconductor (EIS) structure. As is suggested by its name, an arbitrary point on LAPS surface can be selected for measurement by illuminating the point with a focused laser beam. In this study, we fabricated micro fluidic channels on the sensing surface of LAPS by photolithography using the SU-8 and PDMS (polydimethylsiloxane) technology, and investigated the possibility of its application as a component in integrated micro chemical analysis systems similar to Lab-on-a-chip and micro-TAS. The design and fabrication of the device and the results of measurement will be reported.

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環境モニタリング用マイクロ電気泳動チップ（XV）：環境水中の低濃度溶存有機物の迅速キャラクタリゼーション

産総研、神戸商船大＊

○脇田慎一、申　双竜、黒澤　茂、福士惠一＊、竹田さほり

MICRO CHIP BASED CAPILLARY ELECTROPHORESIS FOR ENVIRONMENTAL MONITORING (XV):
HIGH THROUHUPUT CHARACTERIZATION FOR DISSOLVED ORGANIC CARBON AT LOW LEVEL IN ENVIRONMENTAL WATERS

Shin-ichi WAKIDA, Shuanglong SHEN, Shigeru KUROSAWA, Keiichi FUKUSHI*and Sahori TAKEDA
National Institute of Advanced Industrial Science and Technology (AIST),
Ikeda, Osaka 563-8577
*Research Institute for Marine Cargo Transportation, Kobe Univ. of Mercantile Marine,
Higashinada, Kobe 658-0022

We studied on high throughput characterization for dissolved organic carbon (DOC) at low level concentration in waters using microchip based capillary electrophoresis (CE) with laser induced fluorescence (LIF) detection. The applied voltage and the running buffer were investigated to control the simple floating injection and CGE separation for convenient cross type microchips made from PMMA. We obtained high throughput data within 2 min for the reproducible separation of fluorescein isothiocyanate (FITC) labeled water samples at a few ppm level without pre- concentration process. We applied for real samples of the Lake Biwa, which was used good for drinking-water source because of excellent water quality, at two sampling points (12B and 17B) of the north part of the Lake. We discussed the results of seasonal DOC behavior in the Lake Biwa.

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疎水性架橋高分子を用いた容量式湿度センサの研究・開発

株式会社　山武

黒岩　孝朗

DEVELOPMENT OF CAPACITIVE HUMIDITY SENSORS WITH HYDROPHOBIC CROSS-LINKED POLYMERS AS SENSING MATERIAL

Takaaki KUROIWA

Research & Development Headquarters, Yamatake Corporation
1-12-2，Kawana, Fujisawa, Kanagawa, 251-8522, Japan

Humidity sensors with capacitive output have been widely adapted to the measurement of relative humidity in a variety of applications, for example, building controls, plant automation, semiconductor clean room, food industry, pharmaceutical industry, bio-clean room, hospital, agriculture, horticulture and so on. Most of the capacitive sensors now in the market utilize commercially available engineered plastics. In this development direct cross-linking process of the thin spin-coated polymers on a substrate has been developed utilizing a series of tailor- made monomers and oligomers. Newly developed hydrophobic cross-linked polymers have been applied and have been proved to show long term stability over 15 years of sensor life under indoor and outdoor environments.
This paper describes the basic approaches to develop capacitive humidity sensors having both superior initial performance and long term performance with thin film technology.

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微小電極及びマイクロ分析チップの開発と生体、環境センシングへの応用

NTT MI研

○丹羽　修

DEVELOPMENT OF MICROELECTRODES AND MICROANALYTICAL DEVICES TO APPLY FOR BIOLOGICAL AND ENVIRONMENTAL SENSING

Osamu NIWA

NTT Microsystem Integration Laboratories, NTT Corporation,
3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198

Miniaturization of analytical instrument is now of great interest and various kind of microsensors and microanalytical devices have been developed. We have been studied microarray electrodes fabricated with photolithograpy and dry-etching to improve the sensitivity of biomolecules. The thin film biosensors are incorporated in the microfluidic devices and applied for monitoring secretion of neurotransmitters and hormones from cultured cells. The optical detection method is also employed to develop miniaturized chemical sensors. For example, small biomolecules can be detected by surface plasmon resonance sensor combined with microfluidic device. This enables us to image various reactions for enzyme sensors which are very important for multi-channel detection. We also developed microfluidic device to detect air pollutants such as benzene, toluene and xylene (BTX) by UV spectroscopic measurment after pre-concentration of each gas molecule in the adsorbent.

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血液ガス分析を目的とした微小センシングシステム

筑波大物質工

○小島慎平、鈴木博章

A MICRO SENSING SYSTEM FOR BLOOD GAS ANALYSIS

Shimpey KOJIMA, Hiroaki SUZUKI

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

An on-line micro system for the analysis of blood gases was developed. It consists of a reference electrode module, a sensing module with integrated electrodes for pO₂, pCO₂, pH, and a sampling module. Thin-film Ag/AgCl elements used in these electrodes feature a polyimide protecting layer and AgCl layers grown from pinholes formed in the protecting layer. The potential of the reference electrode module was very close to that of a macroscopic commercial reference electrode (<5 mV), and a stable potential level could be maintained for 80 h. A standard solution could be withdrawn into the system successfully. The respective electrodes showed clear responses. Linear relationship was observed in their respective calibration plots.

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界面張力の制御による微小送液システム

筑波大物質工

○佐藤　航、鈴木博章

MICRO FLUIDIC TRANSPORT SYSTEM WHICH OPERATES　VIA MANIPULATION OF INTERFACIAL TENSION

Wataru SATOH, Hiroaki SUZUKI

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

An on-chip microfluidic system was constructed which transports a liquid in a micro flow channel by deliberately controlling interfacial tension by electrode potential. It features low driving voltage and power consumption. The system consists of a flow channel, a reservoir, and a three-electrode system. By setting the potentials of the working electrodes at appropriate values, the interfacial tension between the electrolyte solution and the working electrodes changed, resulting in the movement of the liquid. The liquid was transported in a space between the flow channel and the working electrode. Velocity of the liquid increased as the height of the flow channel decreased and applied potential became more negative. Generated current was on the order of tens of μA and accompanying power consumption was on the order of tens of μW.

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微小重金属分析システム

筑波大物質工

○川床理、長岡真吾、鈴木博章

MINIATURIZED ANALYSIS SYSTEM FOR HEAVY METAL IONS

Osamu KAWATOKO, Shingo NAGAOKA, Hiroaki SUZUKI

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

A miniaturized analysis system for the detection of trace heavy metal ions was　developed. The system was constructed with a reference electrode module and a working electrode chip. To minimize the effusion of Cl- ions, a double - junction structure was used for the reference electrode module. Heavy metal ions were detected by anodic stripping voltammetry (ASV). By using a square wave in stripping the deposited heavy metals on a mercury microelectrode array, distinct stripping peaks were observed for Cd2+, Pb2+, and Cu2+ ions. Peak currents were proportional to the concentrations of the respective ions. For Pb2+ ions, a linear relationship was observed between the peak current and the concentration in a range of concentration between 50 nM and 500 nM.

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ダイヤモンド電極を用いたプリンおよびピリミジンの連続的検出

○T. A. IVANDINI, H. OLIVIA, 本多謙介 、藤嶋　昭

SIMULTANEOUS DETECTION OF PURINE AND PYRIMIDINE BASES BY HPLC WITH ELECTROCHEMICAL DETECTION USING HIGHLY BORON DOPED DIAMOND ELECTRODES

T. A. IVANDINI, H. OLIVIA, K. HONDA and A. FUJISHIMA

Department of Applied Chemistry, School of Engineering, The University of Tokyo,
7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656

Highly boron-doped diamond (BDD) electrodes have been examined for simultaneous detection of purine and pyrimidine bases in mild acidic media by using HPLC with amperometric detection. At oxidized BDD electrodes, due to its higher overpotential for oxygen evolution reaction, well-defined anodic peaks were observed for both purine and pyrimidine bases. The chromatograms of adenine, guanine, cytosine, thymine and 5-methylcytosine mixture were well resolved by using silica-based column in a 100 mM ammonium acetate buffer (pH 4.25) and could be detected at AO BDD electrode with the applied potentials of 1.6 V vs. Ag/AgCl. Linear calibration curves were obtained within the concentration range from 0.1 ?M to 10 ?M with the limits of detection (S/N=3) ranging from 26.3 to 162.1 nM.

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電気泳動法による金属フタロシアニン系センサの作製とイオン応答特性

九工大工

○中村一雄、高瀬聡子、清水陽一

PREPARATION OF PHTHALOCYANINE THIN-FILM BY ELECTROPHORETIC DEPOSITION METHOD AND ITS APPLICATION TO ION SENSOR

Kazuo NAKAMURA, Satoko TAKASE and Youichi SHIMIZU

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

Metallophthalocyanine(MePc)-based thin-film electrodes were prepared by an electrophoretic deposition method on indium tin oxide (ITO)-glass substrate from various organic solutions,　and examined their ion sensing properties. Metal-complex thin-films with high quality and stability could be deposited cathodically under fixed DC field between 0 and -70V at RT. The electrolysis time, the nature of the solvent, and the electrophoretic potential are effect on the thin film morphology. The manganese phthalocyanine and the cobalt phthalocyanine thin-film electrodes showed good potentiometric sensing to H₂O₂,i.e., EMF responses of these sensors were linear to the logarism of H₂O₂ concentration between 1.0x10^-6 and 1.0x10^-3M with 90% response time of ca. 1min at 30℃. Furthermore it was revealed that the cobalt naphthalocyanine thin-film electrode gave high potentiality to the amperometric sensing to hydrogen-phosphate ion.

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分子レセプタとしてカリックスアレーン誘導体を用いたセンサ開発

岡山大・薬、岡山県警科捜研*、東京化成**

○勝 　孝、岡木望美、渡辺清之*、高石清香**、横洲博親**

CALIXARENE DERIVATIVES AS MOLECULAR RECEPTORS FOR ION SENSORS

Takashi KATSU, Nozomi OKAKI, Kiyoyuki WATANABE*, Kiyoka TAKAISHI**, and Hirochika YOKOSU**

Faculty of Pharmaceutical Sciences, Okayama University,
Tsushima, Okayama 700-8530, Japan
*Criminal Investigation Laboratory, Okayama Prefectural Police Headquarters,
1-3-2, Tonda-cho, Okayama 700-0816, Japan
**Tokyo Kasei Kogyo Co. Ltd.,
6-15-9, Toshima, Kita-ku, Tokyo 114-0003, Japan

In order to develop molecular receptors for ion sensors, we examined the ability of calix[6]arene and calix[8]arene derivatives to discriminate organic ammonium ions. We found that p-tert-butylcalix[8]arene-octaacetic acid octaethyl ester and calix[8]arene-octaacetic acid octaethyl ester well recognized 2-phenylethylamine and phenylalanine methyl ester compared with the corresponding calix[6]arene derivatives. Moreover, the calix[8]arene derivatives, especially one having tert-butyl groups, gave better selectivity against biologically active amines of a complicated structure such as norephedrine. We discussed the interaction between calixarenes and organic ammonium ions from the viewpoint of molecular symmetries.

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ヘテロコア型光ファイバを用いた酸濃度センサ

創価大学大学院工学研究科

○甲斐俊典・田中友・伊賀光博・関篤志・渡辺一弘

ACID SENSOR BASED ON A HETERO-CORE OPTICAL FIBER

Toshinori KAI、 Yu TANAKA*、 Mitsuhiro IGA、 Atsushi SEKI**、 Kazuhiro WATANABE

Graduate School of Engineering、 *Department of Information systems、
**Department of Bioengineering、 Soka University
1-236 Tangi、 Hachiouji、 Tokyo 192-8577 Japan

Chromoxane Cyanine R dye which is acid indicator was immobilized on the surface of Hetero-core optical fiber by using sol-gel method for measuring acid concentration. When the Hetero-core portion of the fiber was immersed in HNO₃ solution (0.2〜10.0M) , the propagation loss at wavelength of 535nm around was observed. Furthermore, propagation loss gradually increases with the increasing of HNO₃ concentration. These results show that this fiber sensor would be useful for acid measurement. Experiments for sensor characteristics against hetero-core length and film thickness were performed from the view point of sensitivity. The results indicated that the sensitivity was independent of hetero-core length, but film thickness affected the sensitivity.

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ＳＰＲ免疫センサとマイクロチャネルセルを用いた環境ホルモン関連物質の２成分同時検出システム

（九大先端センター1、九大院薬2、産総研3、近大九州工4、オムロン5）

○三浦則雄1、カウベリ・ゴビ1、正山征洋2、前田英明3、河済博文4、岩坂博之5

SPR IMMUNOSENSING SYSTEM USING MICROCHANNEL CELL FOR SIMULTANEOUS DETECTION OF TWO ENDOCRINE-DISRUPTING CHEMICALS

Norio MIURA1, K. Vengatajalabathy GOBI1, Yukihiro SHOYAMA2, Hideaki MAEDA3, Hirofumi KAWAZUMI4, Hiroyuki IWASAKA5
1 Advanced Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
2 Graduate School of Pharmaceutical Sciences, Kyushu University,
3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582
3 Micro-space Chemistry Laboratory, AIST, 807-1 Shuku-machi, Tosu-shi, Saga 841-0052
4 Kinki University, Kyushu, 11-6 Kayanomori Iizuka-shi, Fukuoka 820-8555
5 Omron Corporation, Electric Components Company, Nagaoka Lab., R&D Center
Shimokaiinji,Nagaokakyo-city, Kyoto 617-8150

The endocrine-disrupting chemicals affect the functioning of hormones of human beings as well as animals and are called “environmental hormones”. They exist in various environments at very low concentrations in the range of ppt to ppb levels. Thus, highly sensitive determination of environmental hormones with high selectivity is indispensable in regulating the ecosystem, and the instrumentation that allows the on-site analysis of environmental hormones is paid much attention. In this work, we are aiming at development of handy-type surface-plasmon-resonance (SPR) immunosensing system for highly sensitive, selective, on-site and simultaneous detection of several environmental hormones at low cost. We report here the results of our research investigations on application of immunosensing technique to highly sensitive detection of twp harmful compounds, fabrication of the microchannel, miniaturization of the SPR detector, design of the compact total-sensing-system.

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2単色光源光導波路および光ファイバSPRセンサを用いた免疫反応検出

静岡大学工学部，医学生物学研究所*

鈴木昭裕，藤田丈治，○近藤 淳，松井義和，塩川祥子，窪田 寛*

DETECTION OF IMMUNOREACTION USING OPTICAL WAVE GUIDE SPR SENSOR WITH TOW-COLOR LED AND OPTICAL FIBER SPR SENSOR

Faculty of Engineering, Shizuoka University, *Medical and Biological
Laboratories CO., LTD.

Akihiro SUZUKI, George FUGITA, Jun KONDOH, Yoshikazu MATSUI, Showko SHIOKAWA, Hiroshi KUBOTA*

Surface plasmon resonance (SPR) sensors have been widely utilized as chemical and biochemical sensors. In this paper, we describe the experimental results of immunoreaction measurements with the SPR sensors. Two SPR sensors are utilized. One is optical waveguide SPR sensor with two-color LED and the other is optical fiber SPR sensor with one LED. A goat IgG is used as antigen and an anti-goat IgG (rabbit) is as antibody. The antigen is immobilized onto the gold surface and the antigen-antibody reaction is measured. The results indicate that both SPR sensor systems can detect the immunoreaction.

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抗原抗体反応を利用した光導波路インスリンセンサ

横浜国大院環境情報

○原紀子、内山兼一、許一太、雨宮隆、伊藤公紀

AN INSULIN SENSOR BASED ON OPTICAL WAVEGUIDES AND THE ANTIGEN‐ANTIBODY REACTION

Noriko HARA, Kenichi UCHIYAMA, Yitai XU, Takashi AMEMIYA, Kiminori ITOH

Graduate School of Environment and Information Science, Yokohama National University,
Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan

This study aims to develop an optical waveguide（OWG）insulin sensor as a final target. Since it was found to be an essentially important step to fix the antibody protein on the surface of optical waveguides, a protein immobilization method was established using a peroxidase（POD）instead of expensive insulin. A polymer film in which POD was immobilized was deposited onto potassium ion exchanged glass OWGs. The experimental process, response characteristics, and enzymatic reaction mechanisms are described.

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マッハ・ツェンダー型ウェーブガイドセンサの開発と免疫測定への応用

京都電子工業株式会社、帝人エコ・サイエンス株式会社＊

○安武大輔、松木崇、川口賢治、澤田石一之、大岩俊雄*、清水俊之

DEVELOPMENT OF THE WAVEGUIDE SENSOR BASED ON A MACH-ZEHNDER INTERFEROMETER AND APPLICATION FOR AN IMMUNOASSAY

Daisuke YASUTAKE, Takashi MATSUKI, Kenji KAWAGUCHI, Kazuyuki SAWADAISHI, Toshio OHIWA*, Toshiyuki SHIMIZU

Kyoto Electronics Manufacturing Co., Ltd., 68 Ninodan-cho, Shinden, Kisshoin, Minami-ku, Kyoto, Japan
*Teijin Eco Science Co., Ltd., Sunfield 11 bldg., 3-3-8 Sanda, Minato-ku, Tokyo, Japan

The integrated optical waveguide sensor based on a Mach-Zehnder interferometer is highly sensitive to the slight change of refractive index occurring on the sensor surface. Immunosensing by combining the immobilized antigen on the sensor surface and antibodies enables the trace analysis in short-time. The sensor device is reusable at least 150 times without influence on the sensor surface. This immunosensor detected PCB169 quantitatively in the concentration range 0.25?2.5 ng/mL using 0.2μg/mL antibody solution.

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抗体固定ビーズを用いた免疫センサの応答再現性評価 (II)

徳島大工

○渕脇　雄介、力武　浩太郎、二神　規通、安澤　幹人

REPRODUCIBILITY EVALUATION OF IMMUNOSENSOR WITH ANTIBODY-IMMOBILIZED BEADS COLUMN (II)

Yusuke FUCHIWAKI, Kotaro RIKITAKE, Norimichi FUTAGAMI, Mikito YASUZAWA

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

The reproducibility of the antibody-immobilized beads by the acidic antigen-antibody bonds cleavage treatment was performed using an optical procedure. The fluorescein derivative was conjugated to the antigen in order to determine the affinity of the immobilized antibody. The attempt to reduce the nonspecific adsorption of fluorescein-labeled antigen to immobilized antibody was also performed by adding polyethylene glycol and poly(2-methacryloyloxyethyl phosphorylcholine) in the reaction solutions. Although, both polymers were effective to reduce the nonspecific adsorption, either could eliminate the nonspecific adsorption. Fair reproducibility was observed for approximately first five repetition, while the affinity reduction of the immobilized antibody was inevitable by the acidic treatment of pH 3.

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吸着ストリッピングボルタンメトリーによる高感度アセチルコリンエステラーゼ活性測定とそのペプチドホルモン検出への応用（2）

筑波大化1・産総研生物機能工学2

○松浦宏昭1、佐藤　縁2、澤口隆博2、水谷文雄1、2

HIGH SENSITIVE DETERMINATION OF ACETYLCHOLINESTERASE ACTIVITY BY USING ADSORPTIVE STRIPPING VOLTAMMETRY AND ITS APPLICATION TO MEASUREMENT OF PEPTIDE HORMONE (2)

Hiroaki MATSUURA1, Yukari SATO2, Takahiro SAWAGUCHI2, and Fumio MIZUTANI1,2

1 Department of Chemistry, University of Tsukuba, 1-1-1 Tsukuba, Ibaraki
305-8571
2 National Institute of Advanced Industrial Science and Technology (AIST),
Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566

In order to determine a peptide hormone, B-type natriuretic peptide (BNP) with high sensitivity at enzyme-linked immunosorbent assay (ELISA), we have utilized an adsorptive stripping voltammetric method. Thiocholine, which was produced through the reaction catalyzed by the acetylcholinesterase, was chemisorbed on a silver electrode, and then was electrochemically desorbed. The charge passed through the desorption process was proportional to the number of adsorbed thiocholine molecules on the silver electrode, hence to the acetylcholinesterase activity. Then, we have developed the ELISA using AChE as labeled enzyme. Using competitive immunoreaction method of antigen and antibody-enzyme conjugate, we demonstrated that the BNP could be determined in the concentration range from 40 to 200 ppt.

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アスコルビン酸応答を除去した修飾電極とそのバイオセンサーへの応用

創価大学工学部

○久保いづみ、前原信義

THE MODIFIED ELECTRODE FOR THE PROTECTION OF OXIDATIVE REACTION OF ASCORBIC ACID AND ITS APPLICATION TO BIOSENSOR

Izumi KUBO, Nobuyoshi MAEHARA
Department of Bioinformatics, Faculty of engineering, Soka University
Hachioji-shi, Tokyo, 192-8677

A surface of gold electrode was modified with a self-assembled monolayer in order to protect the oxidation of ascorbic acid, which exists in biological fluid. The electrode was prepared by the modification with 7-carboxyheptanethiol (7C). The modified electrode did not show any anodic response to ascorbic acid but oxidize Co(phen)32+ which can be used as a mediator of biosensor. Fructose biosensor was fabricated by the immobilization of Fructose Dehydrogenase(FDH) on 7C. Amperometric determination of fructose with the FDH and 7C modified electrode was performed at the range of 0.2-2 mM fructose.

 

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プレーナ型バイオセンサを用いたデジタル尿糖計の開発

タニタ

○伊藤成史，大橋昭王，齋藤　敦，池田　悟，松本　達

DEVELOPMENT OF A QUANTITATIVE URINE GLUCOSE METER USING A PLANER AMPEROMETRIC BIOSENSOR

Narushi ITO, Akio OHASHI, Atushi SAITO, Satoshi IKEDA, Toru MATSUMOTO

New Products Development Dept., TANITA Corporation
1-14-2, Maeno-cho, Itabashi-ku, Tokyo 174-8630, Japan

This report describes a development of quantitative urine glucose meter for home use diabetic care. A glucose sensor in the urine glucose meter is based on amperometric detection of hydrogen peroxide generated by a glucose oxidase-catalyzed oxidation of glucose. Through the urine glucose meter development, a compact size, cleanness and an easily operation were considered. The meter demonstrated its capability of accurately and consistently determining glucose concentrations in urine samples ranging from 0 to 2000 mg/dl without dilution. Furthermore, in tests for urine samples an excellent correlation coefficient of 0.975 (Y=0.925X+1.27, n=166) was obtained between the meter and a clinical analyzer.

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セルロース誘導体を過酸化水素選択透過膜とする長寿命グルコースセンサチップの開発

東陶機器（株）

○ルイ　昌生，井口　智美

A LONG-TERM STABLE GLUCOSE SENSOR WITH A PERMSELECTIVE MEMBRANE CONSISTING OF CELLULOSE DERIVATVES

Changsheng RUI and Tomomi IGUCHI

Research Group, TOTO LTD
2-1-1 Nakashima, Kokurakita-ku, Kitakyushu 802-8601, Japan

The glucose sensor with cellulose derivatives having aldehyde and acetyl groups (ACA) as the permselective membrane for hydrogen peroxide directly formed onto the surface of a Pt electrode, has been proved to give high selectivity and excellent stability. The selectivity, however, deteriorated within one month under continual use. The cause of the deterioration is considered to be the hydrolysis of acetyl group due to the electron-deficiency under continual application of the potential at the surface of Pt electrode. The deterioration is greatly retarded by employing a spacer between the ACA membrane and the Pt electrode. As a result, the glucose sensor having this structure shows excellent long-term stability. For example, the selectivity (the ratio of the current from ascorbic acid to that from glucose at the same concentration) is less than 3% even after use at room temperature under continual potential application for more than 7 months.

 

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分子インプリントポリマーのゲート効果に対する電気的相互作用の影響

（芝浦工業大）　○関根真一、吉見靖男、平野克比古
（早稲田大）　　　服部浩二、酒井清孝

A study of electric interaction on the “gate effect” of molecularly imprinted polymer

S. Sekine1, Y. Yoshimi1, K. Hattori2, K. Hirano1, K. Sakai2

1Department of Applied Chemistry, Shibaura Institute of Technology, Minato-ku, Tokyo 108-8548
2Department of Chemical Engineering, Waseda University, Shinjyuku-ku, Tokyo 169-8555

Molecularly imprinted polymer (MIP) shows morphological change with the recognition of its template. This phenomenon is termed as “gate effect”. The authors have been developing a sensor with amperometric detection of change in permeability of redox marker in the MIP layer grafted on electrode. In the present research, they observed the influence of the electric charge of the redox marker on the gate effect in order to estimate the contribution of the electric interaction between the MIP and the marker. The authors prepared poly (methacrylic acid-co-ethyleneglycol dimethacrylate) imprinted with theophylline on indium-tin oxide (ITO) electrode. Cyclic voltammetry (CV) was performed with the grafted ITO electrode. The peak current was compared between the presence and the absence of 5 mM theophylline. As the results, the faradaic current of anionic [Fe(CN)₆]4- was enhanced in the presence of theophylline very clearly (the degree of change was about 10 %), however the degree of gate effect was unstable. The gate effect of nonionic hydroquinone and cationic [Ru(NH₃)₆]3+ were very small to estimate. Those results show that the electric interaction is a important factor for the occurrence of the gate effect.

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GOx/OPPy/Pt-ダイヤモンドマイクロ電極でのグルコースの電気化学的検出

東大院工　

○Olivia Herlambang, Bulusu V. Sarada, 本多健介, 藤嶋 昭

CONTINUOUS GLUCOSE MONITORING　AT GOx/OPPy/Pt-DIAMOND MICROFIBER ELECTRODES

Olivia HERLAMBANG, Bulusu SARADA, Kensuke HONDA, Akira FUJISHIMA

Department of Applied Chemistry, School of Engineering, the University of Tokyo
KSP BLDG., East 612, 3-2-1- Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa, 213-0012

A novel glucose sensor system for in vivo detection has been developed using boron-doped diamond microfiber (BDDMF) electrodes. The electrodes were modified with platinum nano-particles to detect H₂O₂, which was enzymatically produced by glucose oxidase (GOx) immobilized on the electrode surface. Deposition conditions for Pt nano-particles and immobilization of GOx were optimized. The electrodes were also modified with OPPy, a kind of polymer, to overcome the interference problem. Amperometric measurements of glucose performed at 475 mV gave a linear calibration curves in the range of 1 to 70 mM, with an RSD of 3.7 % for 5 injections of 100 ?M glucose. The electrodes have shown good stability during 3-month period of measurements with perfect suppression of AA as interfering compounds.

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微細針状酵素センサの作製及びその評価

徳島大工、東洋精密工業*

○安澤幹人、高岡宏樹*、古川晋也、村上淳也*、清水利泰*、今井信治*

FABRICATION AND EVALUATION OF FINE NEEDLE TYPE ENZYME SENSORS

Mikito YASUZAWA, Hiroki TAKAOKA*, Shinya FURUKAWA, Junya MURAKAMI*, Toshiyasu SHIMIZU*, Shinji IMAI*

Department of Chemical Science and Technology, The University of Tokushima,
Tokushima-shi, Tokushima 770-8506
*Toyo Precision Parts MFG. Co., Ltd., Yamatotakada-shi, Nara 635-0066

New fine needle type glucose sensors were fabricated by immobilizing glucose oxidase (GOD) on the surface of the platinum sputtiring film formed on super-elastic Ni-Ti alloy wire. The immobilization of GOD was successfully performed on the platinum sputtiring film by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) in the presence of GOD. The glucose sensor properties of the obtained electrodes were performed in the phosphate buffer solution (pH 7.4) containing NaCl. Although the response current increased with the increase of glucose concentration of up to 22 mmol dm^-3, the linear relationships range was up to 5 mmol dm^-3. The response current of the obtained electrode reached to a stable current within 20 seconds.

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細胞膜モデルコンプレックス固定化QCMの環境ホルモンセンサーへの応用

創価大工

○中根優子、久保いづみ

Application to the Endcrine Disrupting Chemicals (EDCs) sensor of the cell membrane model complex immobilized on QCM

Yuko NAKANE , Izumi KUBO

Department of Bioengineering, Faculty of Engineering, Soka University
1-236 Tangi, Hachioji, Tokyo 192-8577 Japan

bR-liposome complex is composed from bacteriorhodopsin and liposome. Bacteriorhodopsin is one of the protein of extreme halophilic bacteria and has negative charge. Liposome was prepared from DOTAP (positively charged lipid) and DOPC (neutral lipid). bR and liposome formed complex by electrostatic force. And the complex can be used as cell membrane model complex. The complex was broken by EDCs and the phenomena showed the concentration dependence. We used the complex as recognition element of the sensor for EDCs’ in this study. The complex was immobilized on QCM surface with alkanethiols. Three alcanethiols; Mercaptopropionic acid(3C), 7-Carboxy-1-Heptanethiol(7C), 8-Amino-1-Octanethiol, hydrochloride (8A) were used to modified the surface of electrode. The complex was immobilized onto the alkanethiols by electrostatic force. The calibration curve of nonylphenol(0.05-1.0ppm) with the complex immobilized QCM was demonstrated. The sensor did not respond to TritonX-100. Thus the sensor is selective to nonlylphenol.

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植物の生体電位の統計的解析による環境認知

金沢星稜大学*，富山大学工学部**，埼玉大学工学部***，東京電機大学 ****，竹中庭園緑化*****

新保 達也*，○大薮多可志*，広林 茂樹**，勝部 昭明***，原 和裕****，竹中 幸三郎*****

RECOGNITION OF ENVIRONMENTAL CHANGES USING STATISTICAL ANALYSIS OF PLANT BIOELECTRIC POTENTIAL

Tatsuya SHINBO*, Takashi OYABU*, Shigeki HIROBAYASHI**, Teruaki KATSUBE***, Kazuhiro HARA****, Kouzaburo TAKENAKA*****

*Kanazawa Seiryo University, Kanazawa 920-8620, Japan
**Faculty of Engineering, Toyama University, Toyama 930-8555, Japan
***Faculty of Engineering, Saitama University, Saitama 338-8570, Japan
****Tokyo Denki University, Chiyoda-ku 101-8457, Japan
*****Takenaka Garden Afforestation Co. Ltd., Edogawa-ku 134-0091, Japan

The Bioelectric potential of a foliage plant changes according to an occupant's behavior, for example entering the room in which the plant is installed, as well as watering and touching the plant. The potential shows the impulse responses due to the behaviors. In this study, the integrated values of the bioelectric potential were adopted to identify the behaviors. There are two types of values. Those were derived by integrating the bioelectric potential characteristics for a minute (vm1) and for an hour (vh1) respectively. The histogram of the values vm1 for the steady state took a perfectly normal distribution. The frequencies of vm1 for the behaviors were out of place compared with the steady state distribution. The system can identify the behaviors by examining the frequency table of vm1. Conversely, the plant gives us some suggestions using bioelectric potential characteristics. A clue for communication between humans and plants was also obtained. The vh1, the integrated value for an hour, becomes higher as the average room temperature (tr) becomes lower. There was a negative correlation coefficient between vm1 and tr. There were two groups in the scatter diagram of the variables vm1and tr.

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溶液中における水晶振動子の浸漬角度依存性

鹿児島大院理工

○ 時村　心、吉本　稔、重信　公哉、内藤　正美

EFFECT OF IMMERSION ANGLE ON QUARTZ CRYSTAL MICROBALANCE IN A NEWTONIAN LIQUID

Shin TOKIMURA, Minoru YOSHIMOTO, Kohya SHIGENOBU, Masayoshi NAITOH

Department of Bioengineering, Faculty of Engineering, Kagoshima University,
1-21-40 Korimoto, Kagoshima 890-0065, Japan

The effect of the immersion angle θ of the QCM in a Newton liquid is investigated using the impedance analyzer. In the previous report, it was obvious that the one-face sealed QCM was dependent on θ. In this presentation, in order to examine this effect in more detail, we focus our aim on the effect of the direction of the electrode and of the immersion depth of the QCM. We also find that the experimental results are in good agreement with the theoretical equation with θ.

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ニュートン流体中における水晶振動子のオーバートーンモードの振る舞い

鹿大院理工

○重信公哉、吉本稔、中島範昭、内藤正美

EFFECT OF IMMERSION ANGLE ON QUARTZ CRYSTAL MICROBALANCE OF OVERTONE MODE IN A NEWTONIAN LIQUID

Kohya SHIGENOBU, Minoru YOSHIMOTO, Noriaki NAKASHIMA, Masami NAITO

Department of Bioengineering, Faculty of Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan

In order to obtain in detail the effect of the immersion angle θ of the one-face sealed quartz crystal microbalance (QCM) in a Newtonian liquid, we investigated the behavior of the QCM of the overtone mode. This experiment indicated that the QCM of the overtone mode depended on θ and that the sensitivity of the QCM of Nth overtone mode was √N times larger than that of the fundamental mode.

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ペルオキシダーゼ修飾カーボンフェルトをフロースルー型検出器とするバイオセンサ

埼玉工大工

○小森　雅仁、長谷部　靖、内山　俊一

BIOSENSOR USING PEROXIDASE-IMMOBILIZED CARBON FELT AS FLOW-THROUGH DETECTOR

Masahito KOMORI, Yasushi HASEBE, Shunichi UCHIYAMA

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

A carbon felt (CF) electrode, which is a microelectrode ensemble of carbon fiber (<10 μm) with a random three-dimensional structure, was chemically modified with horseradish peroxidase (HRP) using cyanuric chloride as a linking agent, and the resulting HRP-immobilized CF (HRP-CF) was successfully employed as a bioelectrocatlytic flow-through detector for H₂O₂. Based on the direct electron transfer from the CF to oxidative HRP intermediate, highly sensitive and reproducible cathodic peak currents to H2O2 could be obtained without any mediating species under an applied potential of -0.05 V (vs. Ag/AgCl). The interference of ascorbic acid (AsA), being a donor substrate of peroxidase, can be cancelled by the shift of applied potential to more negative region, and 500 μM of AsA did not cause any observable interference on the response of 50 μM H₂O₂ at -0.25 V (vs. Ag/AgCl). Operational and storage stability of covalently bound HRP via cyanuric chloride was fairly good as compared with those of adsorbed HRP, suggesting that the covalent linkage with cyanuric chloride to HRP is important for enhanced and reproducible responses. The combination of this system with glucose oxidase (GOD) enabled glucose determination in some beverages.

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配位集積型高分子錯体のNOセンシング素子への応用

九工大院生命体工

○淺川雅、春山哲也

DESIGN AND SYNTHESIS OF PMP COMPLEX FOR AN ELECTROTRANSDUCER ON IN SITU NO SENSING

Hitoshi ASAKAWA, Tetsuya HARUYAMA

Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology,
Kitakyushu Science and Research Park, 2-4, Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan

A polymer-metal-polymer (PMP) complex has been designed and synthesized for molecular transducer on amperometric nitric oxide (NO) sensor. The PMP complex behaves as artificial oxidation catalyst of NO. It forms a peculiar structure by coordinative assembly densely. The designed structure consists of polyhistidine, metal ion, and polystyrene sulfonate and gives catalytic function, electro-transduceability and biocompatibility simultaneously. Due to the experimental results, the PMP complex possesses nano-cavity as active center which is controlled under the hydrophobic and electrophilic condition. Using the PMP complex, as electro-transducer, the high selectivity sensor was obtained for NO in aqueous solution.

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多糖類固体フィルムを用いた紫外光の可視化センサ

*東京家政学院筑波女子大短、**茨城大理

○高藤清美*、鏑木悠城**、金子正夫**

VISUALIZING SENSOR FOR ULTRAVIOLET IRRADIATION USING POLYSACCARIDE SOLID FILM

Kiyomi TAKATO*, Yuuki KABURAGI**, Masao KANEKO**

*Tokyo Kasei Gakuin Tsukuba Junior College,
Tsukuba-shi, Ibaraki-ken 305-0031, Japan
**Faculty of Science, Ibaraki University,
Mito-shi, Ibaraki-ken 305-8512, Japan

A film device to visualize UV irradiation was successfully fabricated by an agarose solid film containing Fluoran dye (FL) and acid generator N-tosyloxyphthalimide (TOPI) and 2-propanol medium, and the mechanism and kinetics of this system were investigated. The kinetic constants of the reactions in agarose solid film system were estimated by solving the differential equations by the formation of the colored FL with changing the parameters based on a least square method. The result was in
accordance with the experimental results to give reaction rate constants of the processes. The results showed an agarose solid film containing FL and TOPI and 2-propanol medium have good capability for visualizing sensor for un-visible UV irradiation.

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基質と相互作用する物質を含む溶液中での酵素電極の応答

産総研　生物機能工学研究部門

○水谷文雄、矢吹聡一、佐藤　縁、飯島誠一郎

ENZYME ELECTRODE RESPONSE IN A SOLUTION CONTAINING ENZYME SUBSTRATE AND
SPECIES THAT ASSOCIATES WITH THE SUBSTRATE

Fumio MIZUTANUI, Soichi YABUKI, Yukari SATO, Seiichiro IIJIMA

Division of Biological Resources and Functions,
National Institute of Advanced Industrial Science and Technology,
Tsukuba Central 6, Ibaraki 305-8566

Glucose sensor response were recorded in a solution containing 3-aminophenylboronic acid (3-APB). The current response for glucose was reduced by the addition of 3-APB, owing to the formation of enzymatically-inactive glucose/3-APB complexes. The complex formation was applied to the determination of a high concentration range. On the other hand, an enzyme electrode with a chemically-amplified response for methylene blue (MB) was prepared by using a glassy carbon electrode and a layer containing immobilized horseradish peroxidase (HRP). MB is oxidized through HRP-catalyzed reaction to form (MB)OX in the presence of H₂O₂, and regenerated by the electrochemical reduction of (MB)OX. The consumption/regeneration cycle for MB resulted in an amplified response. The recycling electrode was applied to the sensitive measurement of DNA. The current for MB decreased in association with the complexation with DNA, and the current response caused by DNA was also amplified on the recycling electrode. The detection limit of DNA (from salmon testes) was as low as 5 ng/ml.

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ウレアーゼ固定化尿素センサ応答の電気化学制御に関する研究
　
（埼玉工大工）内山俊一、○関岡直行、長谷部靖、萩原時男

STUDIES ON ELECTRRIC CONTROL OF UREASE-IMMOBILIZED UREA ELECTRODE RESPONSES

Shunichi UCHIYAMA, Naoyuki SEKIOKA, Yasushi HASEBE Tokio,HAGIWARA
Department of Applied Chemistry, Faculty of Engineering,Saitama Institute of Technology,
1690, Fusaiji, Okabe Saitama 369-0293

The electrooxidation wave of cysteine residue of jackbean urease surface was observed at + 0.3V vs SCE and this wave decrease slowly by the reaction of maleimide monomer due to its steric effect, although cysteine monomer reacts with maleimide very rapidly. This thiol group of Jackbean urease surface can be used to immobilize to gold surface via Au-S bond, and the urease immobilized gold mesh was combined with ammonia electrode, and a novel urea electrode was fabricated. The sensor response was strongly influenced by electrode potential when enzyme is immobilized. Differing from jackbean urease, both bacillus pasteurii and acidic ureases do not possess thiol group at their surface.

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RESISTANCE TO SURFACTANT FOULING EFFECTS AT CONDUCTING DIAMOND ELECTRODES

東大院工

○Dongchan Shin and Akira Fujishima
Department of Applied Chemistry, School of Engineering, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan

Arben Merkoci, and Joseph Wang
Department of Chemistry and Biochemistry, New Mexico State University
Las Cruces, New Mexico 88003, USA

Boron-doped diamond thin film electrodes display negligible surfactant fouling effects even at high levels of surface-active materials. Dramatic improvements in the stability of the response (compared to glassy carbon electrodes) are illustrated using bovine serum albumin, gelatin, and Triton X-100 in connection with repetitive square-wave voltammetric measurements of the model ascorbic-acid analyte. The voltammetric response of ascorbic acid at the diamond electrode exhibits negligible shifts in peak potentials and minimal depressions of current signals over a wide range of surfactant concentrations (0?750 ppm). Such enhanced antifouling features make diamond electrodes very attractive for numerous real-life electroanalytical sensing applications.

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アルカリシリケート系化合物の炭酸ガス、アルカリ炭酸塩との反応性　　
　　　　　　　　
愛媛大工　

蔵本有夕子、○岡本卓、板垣吉晃、青野宏通、定岡芳彦

REACTIVITY OF ALKALI SILICATES WITH CO₂ GAS AND ALKALI CARBONATE

Ayuko KURAMOTO, Takashi OKAMOTO, Yoshiteru ITAGAKI, Hiromichi AONO, and Yoshihiko SADAOKA

Department of Materials Science and Engineering, Faculty of Engineering, Ehime University,
Matsuyama,790-8577

Some deterioration of sensing characteristics for CO₂ were confirmed for EMF type CO2 gas sensor using a combined electrolyte of Na₂O-Al₂O₃-4SiO₂ glass and YSZ pellet with Na₂CO₃ auxiliary phase. To clarify the deterioration mechanism, the reactivity of each component of the sensor with CO₂ and Na₂CO₃ was examined. The possibility of the formation of some sodium silicates was confirmed by the reaction of Na₂CO₃ with SiO₂ in electrolyte. In addition, the diffusion of Na ion to YSZ from electrolyte was detected. The morphology and chemical characteristics of Na₂CO₃ layer was influenced by the formation process of Na₂CO₃ layer.

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NASICONを用いた電位型CO₂センサにおける対極の安定化

九大院総合理工

○宮地祐治、酒井　剛、島ノ江憲剛、山添　�f

STABILIZATION OF COUNTER ELECTRODE FOR NASICON-BASED POTENTIOMETRIC CO₂ SENSOR

Yuji MIYACHI, Go SAKAI※, Kengo SHIMANOE※, Noboru YAMAZOE※

Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580 ※Department of Materials Science, Faculty of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580

NASICON (Na+ conductor, Na₃Zr₂Si₂PO₁₂)-based potentiometric CO₂ sensor has usually been attached with Au counter electrode, the potential of which is determined by the equilibrium between NASICON surface and partial pressure of O₂ in air, and hence is susceptible to contamination of the surface. In order to stabilize the counter electrode potential of the device, it was tried to introduce BICUVOX (Bi₂Cu_0.1V_0.9O_5.35) or NaCoO₂ in the device as a discrete air reference material or solid reference material, respectively. BICUVOX was found to work well as a stable reference material at a constant operating temperature (450 ℃) regardless of changes in relative humidity and CO₂ concentration. Once kept at room temperature for a few days, however, the recovery of the steady electrode potential on switching to 450 ℃ was rather too sluggish. On the other hand, NaCoO₂ counter electrode could not be stable in the presence of CO₂ and humidity at 450 ℃. When covered with a glass layer, however, it gave quite stable potential at 450 ℃ independent of CO₂ concentrations and relative humidities. Transients of the potential after switching from room temperature to 450 ℃ are under investigation for this electrode.

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NASICONを用いた電流型NO₂センサの検知電極および参照電極材料の検討

九大院総理工

○宮崎洋一、酒井　剛、島ノ江憲剛、三浦則雄、山添　�f

EXPLORATION　OF　SENSING- AND REFERENCE-ELECTRODE　MATERIALS　FOR　NASICON-BASED　AMPEROMETRIC　NO₂　SENSOR

Youichi MIYAZAKI※, Go SAKAI※※, Kengo SHIMANOE※※, Norio MIURA※※※, Noboru YAMAZOE※※

※Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580,Japan ※※Department of Materials Science, Faculty 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

Investigations were carried out for the applicability of NaCoO₂ and ITO(Indium Tin Oxide) to the reference and sensing electrodes of the NASICON-based amperometric NO₂ sensor, respectively. As evaluated from the EMF behavior of the potentiometric devices separately fabricated, the inorganic adhesive-covered NaCoO electrode was more stable to exposure to NO₂ than the same adhesive-covered Au electrode which has been conventionally used, while both electrodes were fairly stable to changes in relative humidity. This suggests that the reference electrode can be better stabilized by the use of NaCoO₂. It was also found that the ITO-attached sensing electrode gave a little larger current response to NO₂, although the current response was disturbed slightly with a change in relative humidity of the surrounding atmosphere.

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ガラス固体電解質によりNi参照電極を密閉した塩素ガスセンサ

愛媛大工

青野宏通、○宮永正太、定岡芳彦

Cl₂ GAS SENSOR USING Ni REFERENCE ELECTRODE COVERED BY GLASSY Na+ CONDUCTING SOLID ELECTROLYTE

Hiromichi AONO, Syouta MIYANAGA, and Yoshihiko SADAOKA

Department of Materials Science and Engineering,Faculty of Engineering,Ehime
University, Matsuyama, 790-8577

EMF type Cl₂ gas sensor using a Ni reference electrode covered by a glassy Na₂O-Al₂O₃-4SiO₂ electrolyte was prepared and those sensing properties were investigated in the range of 0 ~ 7.36ppm at 450-550 ℃. The sensor exhibited a good sensitivity and fast response at 500-550 oC. The electrical potential at Ni reference electrode would be fixed by O₂ concentration from an equiliblium of Ni, NiO, and oxygen diffusion from solid electrolyte. The electron number for the reaction was n=1.3-1.5 which was lower than theoretical n=2.0.

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安定化ジルコニアと亜硝酸塩系材料を組み合わせた高感度NO_xセンサの提案

a九大院総理工、　b九大先端センター

○和間良太郎a、　三浦則雄b

PROPOSAL OF HIGHLY SENSITIVE NO_x SENSOR COUPLED WITH STABILIZED ZIRCONIA AND NITRITE-BASED COMPOUND

Ryotaro WAMA a, Norio MIURA b

a Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580, Japan
b Advanced Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580, Japan

A new type of highly sensitive device based on a stabilized zirconia (YSZ) tube and a potassium nitrite-based compound was designed and its sensing performances were examined for detecting low concentration of NO₂ at relatively high temperature. The difference in potential between the nitrite-based sensing electrode and the Pt/air reference electrode was measured as a sensor signal. This device was found to be able to detect NO₂ at ppb levels at 450℃, although the response time needs to be improved. The NO₂ sensitivity was hardly affected when the concentration of CO₂ in the sample gas was changed from 400 ppm to 1000 ppm, and the sensitivity gave a good linear relationship with the NO₂ concentration in the range 20-400 ppb. A new technique for measuring sensor response was found to shorten the response time. The detailed sensing characteristics as well as the sensing mechanism of the present sensor should be necessary.

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酸化物電極を用いた複素インピーダンス応答型ジルコニアセンサの高温におけるNO_xおよび炭化水素に対する検知特性

a九大院総理工、　b九大先端センター

○中藤充伸a、　三浦則雄b

SENSING PERFORMANCES OF COMPLEX IMPEDANCE-BASED ZIRCONIA SENSORS USING OXIDE ELECTRODE AGAINST NO_x OR HYDROCARBONS AT HIGH TEMPERATURES

Mitsunobu NAKATOU a, Norio MIURA b

a Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580, Japan
b Advanced Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580, Japan

We have already reported a complex impedance-based zirconia sensor using a ZnCr₂O₄-sensing electrode that can detect total NO_x content at high temperature such as 700℃. From a practical point of view, it is very important to examine the influence of water vapor and carbon dioxide on the NO_x sensitivity of the present sensor. Here, we found that the sensitivity to 200 ppm NO (NO₂) was hardly affected by the presence of rather high concentration of H₂O (3-8 vol%) as well as CO₂ (10-15 vol%). In addition, it was confirmed that the NO sensitivity was almost equal to NO₂ sensitivity and the linear relationship was observed between the sensitivity and the NO_x concentration in the range 0-200 ppm even in the presence of 8 vol% H₂O and 15 vol% CO₂. As for the sensing of hydrocarbons, the YSZ-based device using In₂O₃-sensing electrode was found to give good sensitivity and selectivity to CH₄ and C₃H₈ even at rather high temperature such as 900℃.

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燃焼排ガスモニターを目的とした電流検出型炭化水素センサ
（３）アノード電極性能向上
　
大分大工、九大院工＊
　
○Atanu. Dutta, 石原達己＊、西口宏泰、滝田祐作

AMPEROMETRIC HYDROCARBON SENSOR FOR MONITORING EXHAUST GAS
(3) IMPROVEMENT OF ANODE PERFORMANCE

Atanu DUTTA, Tatsumi ISHIHARA*, Hiroyasu NISHIGUCHI, and Yusaku TAKITA

Department of Applied Chemistry, Faculty of Engineering, Oita University,
Dannoharu 700, Oita 870-1192
*Department of Applied Chemustry, Faculty of Engineering, Kyushu University
Hakozaki 6-10-1, Higashiku, Fukuoka 814-8581

Amperometric hydrocarbon sensor using Ni doped LaGaO₃ based oxide electrolyte was investigated. In order to improve the sensitivity, improvement of active electrode for hydrocarbon oxidation was investigated. It was found that sensitivity of the sensor can be improved by doping small amount of metal to Pt anode. In particular, addition of 10 wt% Co to Pt lead to the highest sensitivity and the sensitivity of C₃H₆ is achieved to a value of 800 mA/decade. Therefore, this sensor is highly promising as the sensor for monitoring hydrocarbon concentration in the exhaust gas.

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燃焼排ガスモニターを目的とした電流検出型炭化水素センサ
（４）Fe添加LaGaO₃系電解質による低温作動化

大分大工、九大院工＊

○石原達己＊,Atanu. Dutta, 西口宏泰, 滝田祐作

AMPEROMETRIC HYDROCARBON SENSOR FOR MONITORING EXHAUST GAS
(4)LOW TEMPERATURE OPERATION BY USING Fe DOPED LaGaO₃

Tatsumi ISHIHARA*, Atanu DUTTA, Hiroyasu NISHIGUCHI, and Yusaku TAKITA

Department of Applied Chemistry, Faculty of Engineering, Oita University,
Dannoharu 700, Oita 870-1192
*Department of Applied Chemustry, Faculty of Engineering, Kyushu University
Hakozaki 6-10-1, Higashiku, Fukuoka 814-8581

Amperometric hydrocarbon sensor using Fe doped LaGaO₃ based oxide was investigated and it was found that usage of Fe doped LaGaO₃ electrolyte is effective for increasing sensitivity to C3H6 at low temperature. In particular, the highest sensitivity to C₃H₆ was achieved at 200-250℃ when La_0.7Sr_0.3Ga_0.6Fe_0.4O₃ (LSGF) was used for electrolyte. By decreasing the operating temperature, the selectivity as well as sensitivity increased greatly. Therefore, usage of LSGF for electrolyte is highly effective for increasing the selectivity. The oxygen pumping current is almost independent of CO, CO₂,H₂, NO, and CH₄ but it increase with increasing the carbon number in hydrocarbons.

 

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BiMeVOx(Me=Cu,Nb)の合成と電気化学特性

九大院総理工

〇趙　漢尚、酒井　剛、島ノ江憲剛、山添　�f

PREPARATION AND ELECTROCHEMICAL CHARACTERIZATION OF BIMEVOX(Me=Cu, Nb)

Hansang CHO*, Go SAKAI**, Kengo SHIMANOE**, Noboru YAMAZOE**

*Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580
**Department of Materials Science,Faculty of Engineering Sciences,
Kyushu University, Kasuga-shi, Fukuoka 816-8580

A group of complex metal oxides, BIMEVOX, for which a fraction(x) of V of Bi₄V₂O₁₁ is replaced by foreign metal have been reported to be oxide-ionic conductors. As part of electrochemical characterization, two kinds of oxides in this group, Me = Cu(x=0.1) and Nb(x=0.15), were investigated for their applicability to a potentiometric oxygen sensor. The powders of both oxides, is a structural to gamma-Bi₄V₂O₁₁ phase, were obtained by calcining mixtures of the oxides of constituent metals at 700℃. The oxygen concentration cells using the resulting disks of BIMEVOX were found to work as an oxygen sensor fairly well at 700℃: the number of reaction electrons(n) associated with the reduction of O₂ was close to the theoretical one(4). With lowering operating temperature, however, the O₂-responding properties tended to degrade rather quickly. n was still fairly close to 4 at 600℃, but it was as large as about 10 at 500℃. This indicates that the transport number of oxide-ionic conduction for these oxides deteriorates rather sharply as temperature goes down.

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ZrイオンドープCeO₂系化合物を使った抵抗型酸素センサ

産総研

○伊豆典哉、村山宣光、申ウソク、松原一郎

RESISTIVE OXYGEN SENSORS USING CeO₂ SYSTEM COMPOUND DOPED WITH Zr ION

Noriya IZU, Norimitsu MURAYAMA, Woosuck SHIN, Ichiro MATSUBARA

National Institute of Advanced Industrial Science and Technology,
Nagoya, Aichi 463-8560

The resistive oxygen gas sensors using CeO₂-ZrO₂ thick films with various ZrO₂ concentrations (0-60 mol% ZrO₂) were fabricated. The thick films were screen-printed on alumina substrate with a viscous paste, a mixture of the CeO₂-ZrO₂ powders and organic binder. It became clear that the thick film doped with 10-30 mol% ZrO₂ had the best sensor property in the CeO₂-ZrO₂ thick films.

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Pr₆O₁₁電極を用いたHCセンサの特性

豊田中研

○稲葉忠司,　増岡優美,　佐治啓市,　坂田二郎

CHARACTERRISTIC　OF　HC　SENSOR　USIHG　Pr₆O₁₁ ELECTRODE

Tadashi INABA, Yumi MASUOKA, Keiichi SAJI, Jiro SAKATA

Toyota Central R&D Labs. Inc.,
Nagakute, Aichi 480-1192,Japan

The characteristics of HC sensor which consists of a gas detection cell and an oxygen pump cell have been investigated. In the gas detection cell, a Pt active electrode and a Pr₆O₁₁ inactive electrode were formed on YSZ by sputtering, and the concentration of hydrocarbon gases was detected from the electromotive force generated between both electrodes. The pump cell was assembled to decrease the oxygen concentration of the gas detection space. At 800℃, the gas detection cell showed high output sensitivity for hydrocarbon gases such as CH₄ and C₃H₈. However, the sensitivity was low for H₂ and CO. The sensor output increased when the pump cell was operated in C₃H₈/O₂/N₂. This result shows that it is effective in the improvement of the detection sensitivity of the sensor to decrease the oxygen concentration of the gas detection space by using the pump cell.

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SmFeO₃ガスセンサによる空気質判定の可能性

愛媛大工学

○岡野聡、板垣吉晃、青野宏通、定岡芳彦

AIR QUALITY PREDICTION BY USING SEMICONDUCTING GAS SENSOR WITH NEWLY
FABRICATED SmFeO₃ FILM

Satoshi Okano, Yoshiteru ITAGAKI, Hiromichi AONO, and Yoshihiko SADAOKA

Department of materials Science and Engineering, Faculty of Engineering,
Ehime University, Matsuyama, 790-8577

The conductance changes of SmFeO₃ based p-type gas sensor and n-type SnO₂ gas sensor (TGS2600), with VOCs and NO₂ in air were examined. The use of one sensor was poor to detect a level of contaminated air's quality. By using at least two SmFeO₃ sensor operating at a different temperature, prediction of each contaminated level with VOCs and NO₂ became possible. Furthermore, by the combination with both sensor sub-ppm levels contamination with VOCs and NO₂ was interpretable due to a higher sensitivity of TGS2600 for NO₂ and of SmFeO₃ for VOCs.

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酸化還元能を有する界面活性剤を用いたポルフィリン酸素センサ薄膜の作成と圧力センサへの応用

東工大院生命理工、航空宇宙技術研究所、東工大院理工

○伊藤芳孝、満尾和徳、浅井圭介、佐治哲夫

ELECTROLESS FORMATION OF OXYGEN PRESSURE SENSITIVE THIN FILMS OF PORPHYRIN USING REDOX-ACTIVE SURFACTANTS

Yoshitaka ITO, Kazunori MITSUO, Keisuke ASAI, Tetsuo SAJI

Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology,
Midori-ku, Yokohama 226-8501
Fluid Science Research Center, National Aerospace Laboratory,
Chofu, Tokyo 182-8522
Graduate School of Science and Engineering, Tokyo Institute of Technology,
Meguro-ku, Tokyo 152-8552

Oxygen pressure sensitive thin films of porphyrin with polymer binder are prepared by micelle disruption (MD) method using redox-active surfactants with an azobenzene group. MD method is applicable to many electro-conductive substrates, and controllable to thickness of the thin film with plating time. Thickness of oxygen pressure sensitive thin films prepared by MD method is much thinner than that of the film prepared by the traditional spray method. Therefore, the thin films prepared by MD method are supposed to have an improvement in time response. Stern-Volmer plot of the thin films prepared by MD method has good linearity and sensitivity. These results indicate that the thin films prepared by MD method have an excellent oxygen pressure sensitive characteristic.

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ポルフィリン薄膜の吸収スペクトル変化を利用した微量SO₂,NO₂,HClガスの認識

(愛媛大工)

○出来克之、板垣吉晃、青野宏通、定岡芳彦

DETCTION OF SO₂,NO₂,AND HCl GASES USING ABSORPTION SPECTRAL CHANGES OF PORPHYRIN THIN FILMS

Katsuyuki DEKI, Yoshiteru ITAGAKI, Hiromichi AONO, and Yoshihiko SADAOKA

Department of Materials Science and Engineering, Ehime University
Bunkyo-cho 3, Matsuyama-shi, Ehime 790-8577

The optical sensor using porphyrin dyes was investigated for the detection of SO₂, NO₂, and HCl. The sensitivity for dimethoxy-tetraphenylporphyrin (TP(2CH3O-P)PH2) ミ ethylcellulose (EC) composite was larger than that of tetraphenylporphyrin (TPPH2) ミ EC composite. The sensitivity was strongly improved by the utilization of silica-gel painted substrate instead of EC matrix.

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フッ化アルミニウムフタロシアニンNO₂ガスセンサに及ぼす膜厚効果

静岡大学電子科研、電子工研

向　前、○村上健司、渡邉健蔵

EFFECT OF FILM THICKNESS ON THE ALUMINUMFLUORO PHTHALOCYANINE NO₂ GAS SENSOR

Qian XIANG, Kenji MURAKAMI*, Kenzo WATANABE*

Graduate School of Electronic Science and Technologies, and *Research
Institute of Electronics, Shizuoka University
Hamamatsu-shi, Shizuoka 432-8011

The NO₂ gas sensing properties of alminumfluoro phthalocyanine (AlFPc) thin films have been investigated in relation to the film thickness. For the film with 20 nm or more in thickness, the sensing properties are dominated by the inner adsorption effect to show the response drift. In case of the film with 14 nm or less, the properties are governed by the NO3- poisoning effect to produce the sensitivity degradation. In order to avoid the inner adsorption effect or the NO3- poisoning effect, it is necessary to from an very thin film. The film with 2 nm in thickness shows the fast response and complete recovery to the NO₂ doping and dedoping cycles.

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吸着燃焼式センサを用いたアルコールの識別

矢崎総業、＊長崎大工

○ 木戸亜矢子、笹原隆彦、砂山竜男、江頭　誠＊

DISCRIMINATION OF AICOHOLS BY A MICRO SENSOR OF　ADSORPTION /COMBUSTION-TYPE

Ayako KIDO, Takahiko SASAHARA, Tatsuo SUNAYAMA, Makoto EGASHIRA＊

Technical Center, Yazaki Corp., Susono-shi, Shizuoka 410-1194
＊ Faculty of Engineering, Nagasaki University, Nagasaki-shi, Nagasaki 852-8521

Response to six kinds of alcohols of an adsorption/combustion-type sensor were measured by a mode of pulse-driven heating for 0.2 s up to a desired temperature from 100 to 450℃ after adsorption at room temperature for 9.8 s.　　The integral sensitivities (the areas of response peaks) increased with increasing the number of carbon atoms involved in the alcohol molecules. 　The response shapes and more notably their differential profiles were dependent on the molecular structure and the chain length.　　From such different response profiles, it was possible to discriminate and quantify the six kinds of alcohols tested.

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水晶振動子を用いた高感度ガスセンサの開発

鹿児島大学理工、産総研

○仮屋　忠志、黒澤　茂、吉本　稔

DEVELOPMENT OF HIGH SENSITIVITY GAS SENSOR USING THE QUARTZ CRYSTAL MICROBALANCE

Tadashi KARIYA1, Shigeru KUROSAWA2, Minoru YOSHIMOTO1

1Department of Bioengineering, Faculty of Engineering, Kagoshima University,
1-21-40 Korimoto, Kagoshima 890-0065, Japan
2National Institute of Advanced Industrial Science and Technology (AIST),
1-1 Higashi, Tsukuba 305-8565, Japan

The quartz crystal microbalance (QCM) is employed as the ultrasensitive weighting device. We investigate the behavior of the QCM of the high fundamental frequency and the overtone mode in air. In this experiment, we used four types of gases: acetone, chloroform, diethyl-ether and ethanol.　The surface of the QCM is covered with the plasma polymerized membrane. This experiment indicates that the QCM used have the high gas selectivity and the high sensitivity.

 

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植物の空気汚染浄化プロセスと生体電位反応

埼大工　○長谷川有貴，勝部昭明，埼大教　浅田茂裕

THE AIR POLLUTION PURIFICATION PROCESS OF PLANT AND BIOELECTRICAL POTENTIAL RESPONSES

Yuki HASEGAWA, Teruaki KATSUBE

Department of Information and Computer Sciences, Faculty of Engineering,
Saitama University,
255 Shimo-okubo Sakuraku Saitama-shi Saitama 338-8570
Shigehiro ASADA
Faculty of Education, Saitama University

This report is concerned on an indoor air purification ability of plant. Bioelectrical potential responses for both d.c. and a.c. components characteristics were analyzed to investigate the purification process for formaldehyde, which is a main indoor air pollutant. It was first shown that plant has the high purification ability for formaldehyde and this ability depends on the light condition. It was then clarified that the d.c. bioelectrical potential responds slowly to pollutant concentration change. It was also found from the result of a.c. bioelectrical potential measurement that the a.c. response time was faster than that of d.c. potential response. The correlation between gas purification process and generated bioelectrical potential were discussed to apply the air purification ability of plant in human life.

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EFFECT OF TRANSITION METALS ADDITION ON MESOPOROUS MCM-41 SPV NO₂ GAS SENSOR

Brian Yuliarto, Hao-Shen Zhou, Takeo Yamada, Itaru Honma
Energy Materials Group, Energy Electronics Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba-shi, Ibaraki 305-8568 Japan.

Brian Yuliarto, Yosuke Katsumura
Department of Quantum Engineering and Systems Science, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

Some transition metals (tin, vanadium, and tungsten) were introduced into the mesoporous silica films by sol-gel spin-coating using direct synthesis method. The film structure was characterized by X-ray Ray Diffraction (XRD), N₂ isotherm, and Transmission Electron Microscope (TEM) analyses. The resulting films were then prepared as surface photo voltage (SPV) sensor devices, which is based on metal-insulator-semiconductor structure. The effect of transition metals incorporated on the mesoporous layer structure was investigated and related to the NO₂ gas sensing properties.

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ハロゲン化物イオン−ハロゲン酸イオンを用いた酸性ガスセンサの選択性向上

理研計器��

○今屋浩志、打越祥一、石地 徹

SELECTIVTY FOR ACIDIC GAS DETECTION BY ELECTROCHMEICAL SENSOR USING HALIDE-HALATE ELECTROLYTIC SOLUTION

Hiroshi IMAYA, Syoichi UCHIKOSHI and Toru ISHIJI

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

Amperometric sensors for the detection of acidic gases, such as hydrogen fluoride(HF) and hydrogen chloride(HCl), have been studied. This detection method of acidic gas is based on the electrode reaction properties of halogen liberated from halide ion / halate ion solution by addition of hydrogen ion.
In this study, we have compared several types of electrolyte using Br-, Br-/BrO3- or Br-/IO3- for the acidic gas detection. HF could be detected by Br--IO3- system in the three systems. On the other hand, the good sensitivity for the HCl was showed by using both halate ions. The selectivity of acidic gases such as HF and HCl on the acidic gas sensor was improved by different halate ion for the electrolytes.

 

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火山ガス連続監視用二酸化硫黄センサのフィールド試験特性

光明理化学工業株式会社 、気象庁*

○中村仁、小坂順一*

FIELD-TEST PERFORMANCE OF SULFER DIOXIDE GAS　SENSOR FOR CONTINUOUS-MONITORING OF VOLUCANIC GAS

Hitoshi NAKAMURA, Jun-ichi KOSAKA*

Komyo Rikagaku Kogyo K.K. 1-8-24 Chuo-cho Meguro-ku, Tokyo 152-8503
*Japan Meteorological Agency 1-3-4Otemachi Chiyoda-ku, Tokyo 100-8122

　We have developed a potentiostatic electrolysis type sulfur dioxide(SO₂)sensor for continuous-monitoring of volucanic gas. The sensor has a inboard filter to remove hydrogen sulfide(H₂S) which will be present in volucanic gas. The continuous-monitoring system including the sensor has been installed in Miyakejima for field-test. As a sesult, the sensitivity loss of the sensor was approximately 10%/year.　

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火山ガス検知用電気化学式SO₂センサ

理研計器株式会社

○石地　徹、松田裕之

ELECTOROCHEMICAL GAS SENSOR FOR MONITORING OF SULFUR DIOXIDE IN VALCANIC GAS

Toru ISHIJI and Hiroyuki MATSUDA

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

An amperometric electrochemical sensor for the detection of sulfur dioxide (SO₂) was investigated for the environmental monitoring around the volcano. The working electrode materials of the sensors were evaluated for the oxidation of SO₂. The sensor using a gold black working electrode showed a good sensitivity and selectivity of SO₂ against H₂S. A good linear relationship between the oxidation current of the sensor and SO₂ concentrations was obtained at the optimum electrode potential. On the basis of this knowledge, we reached to develop a very small SO₂ sensor equipped for the wrist-watch type gas monitor.

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WO₃ゾルから調製した薄膜型センサのNO₂応答特性

九大院総理工

○崔　龍圭、酒井　剛、島ノ江憲剛、山添　�f

NO₂ SENSING PROPERTIES OF WO₃ THIN FILM SENSOR DERIVED FROM WO₃ SOL

Yong-Gyu Choi, Go Sakai, Kengo Shimanoe, Noboru Yamazoe

Department of Materials Science, Faculty of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816-8580

Thin films of WO₃ were successfully fabricated on an alumina substrate from a colloidal suspension of WO3.2H₂O mixed with polyethylene glycol (PEG 6000, 2wt%) by spin coating and sintering at 300℃. As revealed by SEM observation, the films consisted of well developed plates of WO₃, each of which was a stack of thin lamella. The WO₃ thin film sensor thus obtained was found to be sensitive enough to detect a few tens ppb NO₂ at 250℃. As compared to the thick film sensor previously reported, the thin film one was found to be superior particularly in the rates of response and recovery on switching-on and -off NO₂.

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酸化インジウム系薄膜センサの塩化水素ガス検知に及ぼす希土類酸化物の添加効果

立命館大理工

○安永幸司、玉置　純、山本善史

EFFECT OF RARE EARTH METAL OXIDE DOPING ON HCl GAS SENSING USING INDIUM OXIDE-BASED THIN FILM SENSORS

Koji YASUNAGA, Jun TAMAKI, and Yoshifumi YAMAMOTO

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

In₂O₃ based thin film sensors, prepared by suspension dropping on SiO₂/Si substrate equipped with Au microelectrodes, have been subjected to the detection of dilute HCl gas (5 ppm) in air at 300-500 ℃, and various rare earth metal oxides were doped into In₂O₃ in order to improve the sensing properties to dilute HCl gas. Among thin film sensors (thickness; 0.6 μm) doped with various rare earth oxides, the Gd₂O₃ doped In₂O₃ thin film sensor showed the highest sensitivity to 5 ppm HCl at the operating temperature of 300-500 ℃. When the film thickness was increased, the sensitivities of Sm₂O₃, Eu₂O₃, Gd₂O₃ doped sensors remained almost unchanged, while the sensitivities was drastically enhanced for Nd₂O₃, Er₂O₃, and Yb₂O₃ doped sensors. The remarkable thickness effect was observed for the latter sensors. Particularly, the sensitivity of Nd₂O₃-In₂O₃ sensor was increased with increasing film thickness and the sensitivity (Ra/Rg) higher than 40 was obtained at 400 ℃ for the film thicker than 25 μm.

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SnO₂薄膜センサの微細構造制御

（九大院総理工）

○酒井　剛、佐藤千晶、松永直樹、島ノ江憲剛、山添　�f

MICROSTRUCTURAL CONTROL OF THIN FILM-TYPE SnO₂ SENSOR

Go SAKAI, Chiaki SATO*, Naoki MATSUNAGA*, Kengo SHIMANOE,
Noboru YAMAZOE

Department of Materials Science, Faculty of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
*Department of Molecular and Material Sciences, Interdisciplinary Graduate School of
Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580

Microstructural control of SnO₂ thin film sensor was attempted by introducing various amounts of ethylene glycol (EG) or polyethylene glycol (PEG) into the aqueous sol of SnO₂ to be spin-coated. As found with powder samples after calcination, the addition of EG or PEG cut the specific surface area of SnO₂ almost in half, while keeping the crystallite size almost intact. Pore size distribution analysis revealed that the average pore diameter was about 6 nm for the powder derived from the neat SnO₂ sol, while it was enlarged to about 20 nm by the addition of PEG1000 by 18wt%. SEM observation of spin-coated thin films revealed that morphology changed from a dense packing of very fine particles to a more porous packing of larger particles with the addition (18wt%) of PEG1000 or PEG6000. The thickness of spin-coated film could be increased by increasing amount of PEG1000 or PEG6000 added. The sensor responses of these films to H₂ gas increased with increasing film thickness. This tendency is considered to result because the porous structure of the film becomes better developped as the amount of PEG increases.

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酸化すず上でのCO表面反応と硫酸基修飾の影響

九工大工

〇尾崎典明, 盛満正嗣, 松永守央

CO REACTION ON SnO₂ SURFACE AND EFFECTS OF THE SURFACE MODIFICATION WITH SURFACE GROUPS

Noriaki OZAKI,Masatsugu MORIMITSU,Morio MATSUNAGA

Department of Materials Science,Graduate School of Engineering
Kyushu Institute of Technology
Kitakyushu-si,Fukuoka 804-8550,Japan

The surface adsorbates and the CO adsorption on SnO₂ thin films modified and unmodified with sulfate groups were investigated by FTIR-RAS (Reflection Adsorption Spectroscopy). The SnO₂ thin film was prepared by thermal decomposition of a SnCl₄ solution on a tantalum substrate, and the surface modification was carried out by dipping it into different concentrations of sulfuric acid solutions followed by calcination. The surface modification produced sulfate species and increased surface hydroxyl groups on SnO₂. Some particular adsorption peaks for CO surface reaction were confirmed and were enhanced as the concentration of sulfuric acid increased. From the results, the adsorption reaction of CO on the modified SnO₂ surface and its effects on the CO sensitivity were discussed.

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