Amperometric CO sensor using LaGaO₃ based solid electrolyte
(2) Effects of Fe additives to the electrolyte

Jun Iwata, Phawachalotorn Amornrat, Hidehisa Hagiwara, Shintaro Ida, and Tatsumi Ishihara

Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-Ku, Fukuoka, 819-0395

Amperometric CO sensor in exhaust gas was studied based on the oxygen pumping current. It was found that the oxygen pumping current sensitively varied with CO concentration when Au and RuO₂ were used for electrode. Combination of In₂O₃-SnO₂ with Au and RuO₂ with La_0.6Sr_0.4CoO₃ is highly effective for increasing CO sensitivity. Pumping current was changed with CO concentration from few ppm to 5000ppm. On the other hand, sensitivity to CO increases by addition of Fe into LaGaO₃ electrolyte. The highest CO sensitivity is achieved at Ls_0.8Sr_0.2Ga_0.85Fe_0.15O₃ for electrolyte. Current of this sensor is not responded to H₂, CH₄, and CO₂ and so this sensor is highly selective to CO.

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コンポジット（NiO+Au）検知極とジルコニアを用いた
プロペンセンサの応答特性の安定化

九大産学連携センター^a、九大炭素資源センター^b、九大院総理工^c

ペルマル エルマレイ^a,†、○ブラディミル プラシニツァ^b、 藤尾 侑輝^c、三浦 則雄^a

STABILIZATION OF SENSING CHARACTERISTICS FOR ZIRCONIA-BASED PROPENE SENSOR BY USING COMPOSITE (NiO+Au) SENSING-ELECTRODE

Perumal ElUMALAI ^a,†, ○ Vladimir V. PLASHNITSA ^b, Yuki FUJIO ^c, Norio MIURA ^a

^a Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^b Research and Education Center of Carbon Resources, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^c Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580

The different amount (1 – 10 wt%) of sub-micron Au particles (0.3 – 0.6 µm) were homogeneously dispersed into NiO matrix and the resulting composites were used as sensing electrodes (SE) of stabilized zirconia-based sensors. The sensor attached with (NiO + 5 wt% Au)-SE (thereinafter: NiO-Au) was found to give highly selective, sensitive and quick response to C₃H₆ (the sensitivity even down to 20 ppm C₃H₆ was as high as about 100 mV) at 600℃ under the wide range of water vapor concentration (2-11 vol.%). Moreover, the present sensor exhibited stable response to C₃H₆ during 57 days examined, in comparison with pure Au-SE, the sensitivity of which decreased significantly after a few days of operation.

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希土類硫酸アンモニウム塩を用いたアンモニアガスセンサ

　　
阪大院工^a、学振^b

○永井つかさ^a,b、田村真治^a、今中信人^a

SOLID ELECTROLYTE TYPE AMMONIA GAS SENSOR APPLYING
RARE EARTH AMMONIUM SULFATE AS THE AUXILIARY SENSING ELECTRODE

Tsukasa NAGAI ^a,b, Shinji TAMURA ^a, Nobuhito IMANAKA ^a

^a Department of Applied Chemistry, Faculty of Engineering, Osaka University,
2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
^b Japan Society for the Promotion of Science
1-8 Chiyoda-ku, Tokyo 102-8472, Japan

Solid electrolyte type ammonia (NH₃) gas sensors were fabricated by using trivalent Al³⁺ ion conducting solid electrolyte ((Al_0.2Zr_1.8)_20/19Nb(PO₄)₃) and rare earth ammonium sulfate (R₂(SO₄)₂･(NH₄)₂SO₄, (R=Ce, Pr, Nd, Sm)) as the auxiliary sensing electrode, and their ammonia gas sensing performance was investigated. The present sensors showed such a superior sensing performance of quantitative, continuous, and reproducible response with obeying the theoretical Nernst relationship. Among the sensors prepared, the sensors with the Ce and Sm salts as the auxiliary sensing electrode showed rapid response, due to their higher thermal stability compare to the Pr and Nd salts, which realizes a high temperature sensor operation.

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YSZを用いた電位応答型VOCガスセンサ
～電極作製条件がセンサ応答特性に与える影響～

愛媛大院理工

○小嶋　裕樹、森　雅美、板垣　吉晃、定岡　芳彦

EFFECTS OF ELECTRODE MATERIALS ON SENSING CHARACTERISTIC
OF YSZ BASED POTENTIOMETRIC VOC SENSOR

Yuki KOJIMA, Masami MORI, Yoshiteru ITAGAKI and Yoshihiko SADAOKA

Graduate School of Science and Engineering, Ehime University,
3 Bunkyo-cho, Matsuyama 790-8577

Solid-state electrochemical sensors for volatile organic compounds (VOCs) based on commercial yttria stabilized zirconia (YSZ) sheet were fabricated. Two types of configurations, Au/YSZ/Pt and Au,Pt/YSZ/Pt, were examined. When each electrode was exposed to several VOCs, the increase in electromotive force (EMF) corresponding to the decrease in the activity of oxygen ion at the sensing electrode was observed. The　Au,Pt/YSZ/Pt sensor was highly repeatable compared to the Au/YSZ/Pt sensor. The linear relationship between the sensitivity, EMF, and logarithmic of VOC concentrations. The variation of the EMF in 0.5~10ppm VOCs/air was in ascending order of; methyl ethyl ketone > ethanol > acetic acid > benzene > o-xylene > toluene > p-xylene.

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NiO検知極を用いた混成電位型ジルコニアセンサによる低濃度VOCの検出

九大院総理工^a、国立環境研究所^b、九大産学連携センター^c

○佐藤 伴光^a、内山 政弘^b、三浦 則雄^c

DETECTION OF LOW CONCENTRATION OF VOC BY MIXED-POTENTIAL-TYPE ZIRCONIA SENSOR USING NiO SENSING-ELECTRODE

○Tomoaki SATO ^a, Masahiro UTIYAMA ^b, Norio MIURA ^c

^a aInterdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^b National Institute for Environmental Studies, Tsukuba-shi, Ibaraki 305-0053
^c Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580

We have recently reported that the mixed-potential-type yttria-stabilized zirconia (YSZ)-based sensor using NiO sensing-electrode (SE) can detect very low concentrations of volatile organic compounds (VOCs) under the wet condition (1.35 vol.% H₂O). In this study, the detailed sensing characteristics to VOCs for the sensor using NiO-SE were evaluated. As a result, it was confirmed that the sensitivities to various VOCs were higher than those to other gases such as C₃H₆, H₂, CO and NO₂. Thus, the responses to various concentrations of pseudo total VOC (hereinafter called p-TVOC) composed of toluene, m-xylene and formaldehyde were measured. It was found that the present sensor could detect very low concentrations of p-TVOC lower than the guideline value (175 ppb) in Japan. In addition, the accuracy in measurement of p-TVOC concentration by the present sensor was comparable to that by a commercial hydrocarbon analyzer.

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特別講演1

-ジルコニアを用いたVOCの微量計測-に向けて

愛媛大学院理工

定岡芳彦

VOC AND OXYGEN DETECTION WITH ZIRCONIA AND SEVERAL ELECTRODES

Yoshihiko SADAOKA

Graduate School of Science and Engineering, Ehime University,
Matsuyama, Ehime 790-8577

The solid-state galvanic cell of the potentiometric oxygen sensor is a concentration cell, Pt|oxide conductor|Pt. The voltage is generated only immediately over the two interfaces between the Pt metal and the zirconia solid electrolyte. For the cell with electrodes, the current-voltage characteristics were influenced with the electrode materials and also the oxygen concentration of the ambient. The EMF of the sensors with a Pt working electrode modified with Au, SiC, Sm₂O₃ and SmFeO₃ responded to the oxygen concentration and the contaminations with VOCs. The modification of the Pt working electrode is useful to detect sub-ppm levels VOCs contaminated in air.

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高機械的強度を有するアルミナ基板担持
ディーゼルパティキュレートセンサ

^a 名大院環境、^b 日本自動車部品総合研究所

○沈 岩柏^a、竹内 貴志^a、日比野 高士^a、原田 敏彦^b、寺西 真哉^b

AN ALUMINA SUBSTRATE-SUPPORTED DIESEL PARTICULATE MATTER SENSOR
WITH HIGH MECHANICAL STRENGTH

Yanbai SHEN ^a, Takashi TAKEUCHI ^a, Takashi HIBINO ^a,
Toshihiko HARADA ^b, and Shinya TERANISHI ^b

^a Graduate School of Environmental Studies, Chikusa-ku, Nagoya University,
Nagoya 464-8601
^b Nippon Soken, Inc.,
Nishio-shi, Aichi-ken, 445-0012

The emission of particulate matter (PM) from diesel engines can currently be removed by ceramic filters, which separate the particles on the filter and then oxidize them to CO₂ at elevated temperatures. To establish this removal system and maintain its performance, the automobile industry needs innovative PM detecting technology. We have recently reported a solid-state PM sensor with a proton-conducting Sn_0.9In_0.1P₂O₇ electrolyte, where highly sensitive and selective carbon sensing was accomplished by electrochemical formation of active oxygen that could react with carbon. However, the electrolyte used in the previous study was merely prepared by pressing the Sn_0.9In_0.1P₂O₇ powder into pellets, due to the difficulty in preparing sintered compacts of this material. In this study, we attempt to develop an alumina substrate-supported PM sensor, allowing high mechanical strength while maintaining the sensitivity as high as possible.

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二酸化マンガンナノ粒子を用いた水素ガスセンサの電気化学特性

京都大学^a、東京理科大学^b

○上田 義勝^a、辻本 将彦^a、古屋仲 秀樹^a、竹内 謙^b、徳田 陽明^a

ELECTROCHEMICAL PROPERTY OF HYDROGEN GAS SENSOR USING A MANGANESE DIOXIDE ELECTROLYTE

Yoshikatsu UEDA ^a, Masahiko TSUJIMOTO ^a, Hideki KOYANAKA ^a,
Ken TAKEUCHI ^b, and Yomei TOKUDA <sup>a

a</sup> Kyoto University
Gokasho Uji, 611-0011
^b Tokyo university of science,
Oshamanbe Hokkaido 049-3514, Japan

We have been researching a hydrogen gas sensor system using an electrolyte made of a manganese dioxide. The sensor system consists of the electrolyte, platinum mesh sheets as electron collector and catalyst, gas flow meter, and data processing unit for display. The sensor system showed output voltages in proportion to hydrogen gas concentrations of 1-99.9% at room temperature. We expected the proton conductivity of the electrolyte^1-8), and the electro-chemical properties were investigated by a method of alternative current impedance.

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燃料電池作動型COセンサの分極特性

静岡大院^a、静岡大工^b、矢崎資源^c

○望月　計^a,c 、菊池　貴之^b 、須藤　雅夫^a,b 、 石黒　義昭^c 、波多野　博憲^c

POLARIZATION CHARACTERISTICS OF FUEL CELL TYPE CO SENSOR

Kei Mochizuki ^a,c, Takayuki Kikuchi ^b, Masao Sudoh ^a,b, Yoshiaki Ishiguro ^c and Hironori Hadano <sup>c

a</sup> Graduate School of Science and Technology, Shizuoka University,
^b Department of Materials Science and Chemical Engineering, Shizuoka University,
Hamamatsu, Shizuoka 432-8561 Japan
^c Gas Equipment Development Center , Yazaki Resources Co.Ltd.
Hamamatsu, Shizuoka 431-3393 Japan

A new amperometric sensor based on proton conducting membrane, Nafion117, to CO was investigated. The platinum loadings on the anode and the cathode were 0.3 mg/cm². Polarization curves were measured using normal hydrogen electrode (NHE) with a potentiostat / galvanostat at 30 and 60 ℃. As the supply gas, a mixed gas of CO and O₂ was introduced into the anode side, air was introduced into the cathode side. As a result, open circuit voltage (OCV) was influenced by mixed potential of the anode. The current density at 60 ℃ was higher than that at 30 ℃, because the conductivity and catalyst activity was enhanced by increasing temperature.

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ポリアニリンナノファイバー膜の作製方法の検討と
アンモニアガス検知特性

愛媛大院理工

○旭拓也、松口正信

FABRICATION OF POLYANILINE NANOFIBER FILMS
AND THEIR NH₃ GAS SENSING PROPERTIES

Takuya ASAHI and Masanobu MATSUGUCHI

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

HCl-doped polyaniline (PANI) nanofibers were prepared on an alumina substrate having a pair of interdigitated gold electrodes. Various fabrication processes based on an interfacial polymerization were applied, and their morphology and NH₃ gas sensing properties of the devices prepared under different conditions were investigated. The HCl-doped PANI nanofiber sensor showed high sensitivity compared with the sensor using conventional PANI particles, whereas response and recovery times were not satisfied. After dedoping the HCl-doped PANI nanofiber, the film was redoped with DiOHP. While nanofiber structure was disappeared during this process, the DiOHP-doped PANI sensor showed the similar sensitivity and the improved response and recovery times compared with those of the HCl-doped PANI nanofiber sensor.

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酸化ビスマス系光ファイバを用いた
分布型水素センサデバイスの基礎特性

横浜国大^a、東京大学^b、エネルギー総合工学研究所^c

○岡崎 慎司^a，中川 英元^b，村田 謙二^c，福田 健三^c

A DISTRIBUTED HYDROGEN GAS SENSOR USING HIGH REFRACTIVE INDEX OPTICAL FIBER

Shinji OKAZAKI ^a, Hidemoto NAKAGAWA ^b, Kenji MURATA ^c, and Kenzo FUKUDA ^c

^a Yokohama National University, 79-5 Tokiwadai Hodogaya-ku Yokohama city
^b Grad. Sch. Med., The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo
^cThe Institute of Applied Energy, 1-14-2 Nishi-Shimbashi Minato-ku, Tokyo

A fiber-optic gas sensor device, which can detect hydrogen leakage along the fiber, was developed. The sensor device was composed of bismuth-based optical fiber (core) and sol-gel derived platinum-supported tungsten trioxide thin film (Pt/WO3 sensing clad). Sensing principle is based on the evanescent-field leakage from the fiber core to the clad region, and the sensor can detect hydrogen gas anywhere along the sensing fiber. Since the refractive index of the bismuth-based optical fiber is comparable to that of tungsten trioxide, realization of the low loss evanescent-type hydrogen sensor is expected. The propagation loss of the fabricated sensor in air condition was 0.25 dB/m. The value should be enough to realize the distributed hydrogen sensing in the range of several tens of meters. The light power propagating through the device of 5 cm length decreased by about 10 % with the exposure to 10 % H₂/N₂ gas and relatively good reproducibility was obtained.

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プロトンポンピングゲート構造による
電界効果トランジスタ型水素センサの高機能化

岡山大院自然科学

○山口 富治、假谷 正敏、紀和 利彦、塚田 啓二

PROTON-PUMPING GATE STRUCTURE
FOR A FIELD-EFFECT TRANSISTOR TYPE HYDROGEN SENSOR

Tomiharu YAMAGUCHI, Masatoshi KARIYA, Toshihiko KIWA and Keiji TSUKADA

Graduate School of Natural Science and Technology, Okayama University,
3-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530

A FET type hydrogen sensor with a triple layer gate structure was developed for in-vehicle and stationary hydrogen sensing systems. The gate layers of the FET sensor consist of an upper palladium(Pd) electrode, a proton conductor membrane and a lower platinum(Pt) electrode. Output signals of DC and AC were obtained from the sensor signal modulated by the AC bias voltage between the Pd and Pt gates. The DC signals responded to hydrogen gas exceeding 100 ppm in nitrogen and the DC sensitivities increased with temperature. The AC signal changed with hydrogen concentration ranging from 100 ppm to 10% in nitrogen. This signal provides the good marker for a self-checking function of the sensor signal drift.

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炭酸塩を補助相とするMetal-Insulator-SiC構造 CO₂センサの検討

九大院総理工^a,b、Linköping Univ.^c

○井上 浩文^a、Mike Andersson ^c、湯浅 雅賀^b、 木田 徹也^b、Anita Lloyd Spetz ^c、島ノ江 憲剛^b

METAL-INSULATOR-SiC-TYPE CO₂ SENSOR ATTACHED
WITH CARBONATE AS AUXILIARY PHASE

Hirofumi INOUE ^a, Mike ANDERSSON ^c, Masayoshi YUASA ^b, Tetsuya KIDA ^b,
Anita Lloyd SPETZ ^c, Kengo SHIMANOE ^b

^a Department of Molecular and Material Sciences,
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^b Department of Material Sciences, Faculty of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580, Japan
^c S-SENCE and Division of Applied Physics, Linköping University,
Linköping, Sweden

A capacitor-type CO₂ sensor attached with a binary carbonate (Li₂CO₃-BaCO₃) as an auxiliary phase on MISiC (Metal-Insulator-Silicon carbide) was fabricated and investigated for its CO₂ sensing properties. The device showed ideal C-V property in air and good CO₂ response in the concentration range of 1-20 % at 400℃. These features allow for the development of compact solid-state CO₂ sensor.

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Pt/TiゲートSi-MOSFET型水素センサの空気中アニーリング効果

日立基礎研

○宇佐川 利幸、菊池 洋太

Air-Annealing Effects for Pt/Ti gate Si-MOSFETs Hydrogen Gas Sensor

Toshiyuki USAGAWA , Yota KIKUCHI

Advanced Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395

Pt gate Si-MOSFETs hydrogen sensors are well-known as typical device structures. Simple thin Pt gate film fabrication, however, should be prohibited in semiconductor IC lines because poor adhesion of Pt on insulators might contaminate other processing equipments, risking the gate films partially peeling off from an industrial fabrication point of view. To improve poor adhesion of Pt, Pt/Ti gate Si-MOS structures, could not help introducing, but the Ti layer should be an inert layer for hydrogen sensing. Air-annealing Pt(15 nm)/Ti(5 nm)-gate Si-metal oxide semiconductor field-effect transistors at 400 ℃ for two hours revives and enhances the hydrogen sensing activation from nearly all the inert sensor characteristics of the Pt(15 nm)/Ti(5 nm)-gate Si-MOSFETs. The sensing amplitudes are changed from 0.0～0.16 V to 0.82～0.96 V under the air diluted 1000ppm hydrogen gas exposure before and after the air annealing. A transmission electron microscope (TEM) and Auger analysis clearly show that one of the causes is the novel mixing of nanocrystalline TiOx and super heavily oxygen-doped amorphous Ti in the Ti-layer formed on the gate oxide SiO₂.

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ペロブスカイト型酸化物を用いた
インピーダンス型アセチレンガスセンサ

九工大院工

○田崎智久、高瀬聡子、清水陽一

IMPEDANCEMETRIC ACETYLENE SENSOR BASED ON PEROVSKITE-TYPE OXIDE

Tomohisa TASAKI, Satoko TAKASE and Youichi SHIMIZU

Department of Applied Chemistry, Graduate School of Engineering,
Kyushu Institute of Technology,
1-1 Sensui-cho, Tobata, City of Kitakyushu, Fukuoka 804-8550

Perovskite-type oxide thin- and thick- films for application of C₂H₂ sensor devices could be synthesized by a polymer precursor method. The sensing characteristics for acetylene and other interference gases, such as NOX, COX and ethylene, were investigated by means of an AC impedance method. Precursor solutions, prepared by dissolving metal nitrates in ethylene glycol with acetylacetone and polyvinylpyrrolidone, as a polymer additive and a coordination agent, respectively, were spin-coated on an alumina substrate and sintered at 750℃ to form the perovskite-type oxide thin-films. For preparation of the thick-films, oxide powders were prepared form the solutions by calcinations at 750℃. The powders were mixed with a polymer to form a paste were screen-pasted and sintered at 850℃. Both SmFeO₃ thin- and thick- film devices showed good sensing characteristics to acetylene in which the sensor resistance was increased with increasing acetylene concentration. Moreover, the selectivity to interference gases showed difference characteristics between the thin- and thick- film devices.

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分子ふるいシリカ/酸化スズセンサによる
フタル酸ジアルキル類の選択的検出

鳥取大学^a，富士電機システムズ^b

○福地健一^a，片田直伸^a，岩田英之^b，丹羽　幹^a

SELECTIVE DETECTION OF DIALKYL PHTHALATE USING MOLECULAR-SIEVING SiO₂/SnO₂ CHEMICAL SENSOR

Ken-ichi FUKUCHI ^a, Naonobu KATADA ^a, Hideyuki IWATA ^b and Miki NIWA ^a

^a Graduate School of Engineering, Tottori University, Tottori 680-8552
^b Fuji Electric Systems, Hino-shi, Tokyo 191-8502

In environments for semiconductor industry, even in clean rooms, atmosphere contains vapors of organic solvents such as toluene (TL), isopropanol (IP) and methylethylketone (MEK), as well as such plasticizers as dioctyl phthalate (DOP), bis(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP). Among them, DOP, DEHP and DBP (dialkyl phthalates, DAPs hereafter) at such a low concentration as 1 mol ppb are known to cause a serious pollution of semiconductor surface when it is precisely designed in nanometric scale. Therefore, selective detection of DAPs in a very low concentration under the co-presence of organic solvent (TL etc.) is required. Up to now, no practical method has been established other than GC-MS (gas chromathgraphy-mass spectroscopy) measurement after collection, trap and concentration procedure. Chemical sensor such as SnO₂ is expected to be suitable for the detection of organic vapor at such a low concentration, but it has no selectivity. We have developed a method to cover the surface of SnO₂ with a silica overlayer with controlled pores using molecular templates. In this study, a silica overlayer was deposited on Pd/SnO₂ in the presence of 1-naphthoate anion as a template. Cavities with controlled sizes were formed after removal of the template. Thus prepared SiO₂/Pd/SnO₂ was applied to a chemical sensor. DAPs were selectively detected by this sensor; the sensitivties to DOP, DEHP and DBP were high on both of the unmodified Pd/SnO₂ sensor and the templated SiO₂/Pd/SnO₂ sensor, while the organic solvents (TL, IP and MEK) gave high sensitivities on the former sensor but low sensitivities on the latter sensor. The sensitivity of SiO₂/Pd/SnO₂ sensor was also high to ethanol and methanol. The obviously higher sensitivities of these alcohols on the SiO₂/Pd/SnO₂ sensor than that of IP suggest that the branched molecule gave the low sensitivity. In addition, dimethyl phthalate showed a high sensitivity on the SiO₂/Pd/SnO₂ sensor, indicating that the phthalates with long alkyl chains had high sensitivities. It is therefore suggested that only linear molecules (or linear parts of molecules) can penetrate into the cavity of the silica overlayer formed in the presence of template molecule and reached the Pd/SnO₂ surface, and hence the long alkyl chain in dialkyl phthalate is selectively detected by the templated sensor.

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BaTiO₃系サーミスタを用いた水素センサの高感度化

九大院総理工

立花 直樹、○湯浅 雅賀、木田 徹也、山添 曻、島ノ江 憲剛

HIGHLY SENSITIVE DETECTION OF HYDROGEN USING BaTiO₃
BASED PTC THERMISTOR

Naoki TACHIBANA ^a, Masayoshi YUASA ^b, Tetsuya KIDA ^b, Noboru YAMAZOE ^b and Kengo SHIMANOE ^b

^a Interdisciplinary Graduate School of Engineering Sciences, Kyushu University
^b Faculty of Engineering Sciences, Kyushu University,
Kasuga, Fukuoka 816-8580, Japan
E-mail:simanoe@mm.kyushu-u.ac.jp

Recently, we have reported a catalytic combustion type hydrogen sensor using a positive temperature coefficient (PTC) thermistor of La-doped BaTiO₃ (L-BT). In this sensor, an increasing in the temperature above the Curie temperature by a catalytic combustion of hydrogen results in drastic change in the resistivity. However, this sensor is not so sensitive to low concentration of hydrogen, because the combustion efficiency of hydrogen is not enough at the operating temperature of this sensor (122.5℃). Some studies have reported that Na,Bi-doped BaTiO₃ shows high curie temperature as compared with the L-BT. Therefore, we focused on fabricating Bi,Na,Nb-doped BaTiO₃ (BNN-BT) in order to obtain gas sensor sensitive to low concentration of hydrogen. The BNN-BT powder was prepared by a conventional solid state reaction and fabricated to stick shaped-disc, and Pt wires were attached to the disc, and voltages between Pt wires were measured under a constant current in air and air containing hydrogen. As the result, the BNN-BT-based thermistor showed higher curie temperature of 146.2℃, so that the fabricated sensor device could detect low concentration of hydrogen more sensitive than the sensor device using L-BT.

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メソ・マクロポーラス酸化スズセンサのガス応答特性
−SiO₂およびSb₂O₅の添加効果−

長崎大 ¹院生産，²工

○原 陸洋¹，兵頭健生¹，清水康博²，江頭　誠²

GAS-SENSING PROPERTIES OF MESO- AND MACRO-POROUS SnO₂ －EFFECTS OF SiO₂ AND Sb₂O₅ ADDITIONS－

Luyang YUAN ¹, Takeo HYODO ¹, Yasuhiro SHIMIZU ² and Makoto EGASHIRA ²

¹ Graduate School of Science and Technology, ² Faculty of Engineering,
Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan

Various SnO₂-based powders with well-developed mesopores and/or macropores were prepared by a sol-gel method employing SnCl₄•5H₂O as a Sn source, and their thick-film sensors were fabricated by screen-printing. Their mesoporous and macroporous structures were controlled by a surfactant (C₂₀H₃₇O₇SNa) and a polymethylmethacrylate (PMMA) microsphere (ca. 800 nm in diameter) as a template, respectively. The introduction of mesopores and macropores into SnO₂ sensors increased significantly their sensor resistance. In addition, the doping of Sb₂O₅ was found to reduce markedly the sensor resistance in air, and increase the response to 1 ppm NO₂ as well as 1000 ppm H₂ in air. Among all sensors tested, meso- and macro-porous SnO₂ mixed with 1 wt% SiO₂ and 5 wt% Sb₂O₅, which were prepared with above two templates, exhibited the largest H₂ and NO₂ responses.

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ゲル膜の温水処理によって作製した
チタニア膜の水素検知特性評価

（豊橋技科大）

○小田 浩之、濱上 寿一、河村 剛、逆井 基次、松田 厚範

HYDROGEN SENSING PROPERTY OF TITANIA THIN FILM
PREPARED BY HOT WATER TREATMENT

Hiroyuki ODA, Jun-ichi HAMAGAMI, Go KAWAMURA,
Mototsugu SAKAI and Atsunori MATSUDA

Department of Material Sciense, Toyohashi University of Technology,
Toyohashi-shi, Aichi 441-8580

Hydrogen is one of the most attractive clean energy sources in the future. However, hydrogen is a dangerous gas with an explosive limit in the concentration from 4 to 75 vol.% in air by an ignition. The development of hydrogen gas sensors with a high performance is very important to realize safe hydrogen energy society. We have investigated on optical hydrogen gas sensors that can operate at room temperature. The development of the preparation process for sensing materials is also important to reduce environmental loading and cost. In this work, we prepared optical hydrogen sensors consisting of titania and palladium by low temperature process under an atmospheric pressure. Photocatalytic titania coating was prepared onto a glass substrate by a sol-gel spin-coating method combined with a hot water treatment at 90℃. Palladium was deposited on the titania coating by a photodeposition process using an ultraviolet lamp. The optical transmittance at a 640 nm-wavelength decreased and was saturated at a constant value within about 3 s by exposing to hydrogen gas at room temperature.

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小型ビーズ形状の半導体ガスセンサのVI特性

エフアイエス株式会社

○河野 晴美、稲澤 領、松本 晋一

CURRENT-VOLTAGE CHARACTERISTICS OF
A MINI BEAD TYPE SEMICONDUCTOR GAS SENSOR

Harumi KOHNO, Osamu INAZAWA and Shinichi MATSUMOTO

FIS Inc.
3-36-3 Kitazono, Itami, Hyogo 664-0891

We developed a mini bead type semiconductor gas sensor for battery operated applications using a pulsed ON-OFF heater driving method. We reported that CO sensitivity was improved by using an intermittent circuit voltage for detection and estimated that the ion conduction of adsorbed water was an influential factor. For further investigation, we have studied the current-voltage characteristics during heater off period to clarify the relationship between the ion conductivity and the water electrolysis effect. We have found that the sensor resistance in air becomes not to be influenced by humidity when the detection voltage is below 1.2V which is equivalent to the Electrical potential difference of water electrolysis. As a result, a high CO sensitivity with no influence from humidity is achieved with 1.2V DC of detection voltage.

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還元雰囲気におけるSnO₂系半導体センサのCO検知機構

愛媛大院理工

○平尾　晋介、山浦　弘之、八尋　秀典

CO SENSING MECHANISM OF TIN DIOXIDE SEMICONDUCTOR SENSORS
IN A REDUCING ATMOSPHERE

Shinsuke HIRAO, Hiroyuki YAMAURA, Hidenori YAHIRO

Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime 790-8577

CO sensing mechanism of SnO₂ and copper oxide-loaded SnO₂ sensors was investigated in a reducing atmosphere. It was found that H₂-TPR profile of SnO₂ consists of three reduction peaks accompanying with the change in sensor resistance. Considering the sensitivity of SnO₂ to CO in a reducing atmosphere, the reversible sensor response to CO may be related with the redox mechanism of surface oxygen of SnO₂: the reduction of surface oxygen by CO and the oxidation by H₂O. This redox cycle may be accelerated by the presence of metallic copper supported on SnO₂.

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貴金属を担持したメソポーラス酸化スズのガス検知特性

長崎大 ¹院生産科学，²工

○津村知典¹、兵頭健生¹、清水康博²

GAS-SENSING PROPERTIES OF MESOPOROUS SnO₂ LOADED WITH NOBLE METAL

Tomonori TSUMURA ¹, Takeo HYODO ¹ and Yasuhiro SHIMIZU ²

¹ Graduate School of Science and Technology,
² Faculty of Engineering,
Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521

The m-SnO₂ powders loaded with noble metals (nM/m-SnO₂, n; the amount of noble metals loading (wt%), M: Pd or Au) have been prepared and their H₂-sensing properties have been investigated in this study. The specific surface area (SSA) of nPd/m-SnO₂ increased with an increase in n, because Pd inhibited the grain growth among SnO₂ crystallites. On the other hand, that of nAu/m-SnO₂ also increased with an increase in n in the range from 0 to 3.32, while too large amounts of Au loading increased the size of crystallites and thus reduced the SSA in the n range higher than 3.32. H₂ sensing properties of m-SnO₂ were improved by the Au loading, but too large amounts of Au loading decreased the response. On the other hand, the H₂ response of nPd/m-SnO₂ increased with an increase in n at low temperature, while the Pd loading to m-SnO₂ was ineffective in the H₂ response at high temperature, because the catalytic combustion properties of H₂ over Pd were much excellent than those over Au.

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熱分析法による吸着燃焼式マイクロガスセンサのエタノール応答機構の 検討

矢崎総業

○笹原　隆彦、　木村 修

ETHANOL RESPONS MECHANISM OF AN ADSORPTION/COMBUSTION-TYPE MICRO GAS SENSOR BASED ON THERMAL ANALYSIS

Takahiko SASAHARA and Osamu KIMURA

Yazaki Corporation, Susono-shi, Shizuoka 410-1194

We have developed an adsorption/combustion-type micro gas sensor showed a large peak response to organic compounds such as ethanol and toluene. The derivative peaks of the response could identify gaseous species with the peak numbers and the positions. Here, we investigated the response mechanism from ethanol response analysis of the sensor controlled with a constant temperature rising and thermal analysis curves measured immediately after ethanol pre-adsorption on the catalytic sensor materials. Both the sensor response and the thermal analysis determinably showed three peaks in their elevated temperature process. It was indicated that the peaks were based on three desorption or decomposition combustion reactions of ethanol adsorbed on the catalytic material surface of the sensor.

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SnO₂半導体上へのO₂吸着とその電気特性

九大院総理工^a,b、Tübingen Univ.^c

○末松昂一 ^a、山田清美 ^a、Michael Hübner ^c、湯浅雅賀 ^b、
木田徹也 ^b、Nicolae Barsan ^c、Udo Weimar ^c、山添 曻 ^b、島ノ江憲剛 ^b

Relationship between O₂ adsorption behavior and their electric properties
for SnO₂ semiconductor gas sensor

Kouichi SUEMATSU ^a, Kiyomi YAMADA ^a, Michael HÜBNER ^c, Masayoshi YUASA ^b,
Tetsuya KIDA ^b, Nicolae BARSAN ^c, Udo WEIMAR ^c, Noboru YAMAZOE ^b, Kengo SHIMANOE ^b

^a Department of Molecular and Material Sciences,
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga, Fukuoka 816-8580, Japan
^b Department of Energy and Material Sciences, Faculty of Engineering Sciences, Kyushu University,
Kasuga, Fukuoka 816-8580, Japan
^c Institute of Physical and Theoretical Chemistry, University of Tubingen,
72076 Tubingen, Germany

It is well known that the oxygen adsorption on the surface of SnO₂ forms the depletion layer in SnO₂ grain, leading to increase the electric resistance. Recently, we have reported theoretical models of response to oxygen for semiconductor gas sensors. It was shown clearly that the depletion in small semiconductor crystals is concerned with the dynamics of adsorption of oxygen molecules. In the reported theory, it was indicated that there are two kinds of depletion state, which are named “Regional depletion” and “Volume depletion”. In the volume depletion, the electric resistance of the SnO₂ film is proportional to P_O2^1/2, where P_O2^1/2 is partial pressure of oxygen. In this study, we aimed to verify the above theory by experiments. The SnO₂ sensor elements were prepared by using small crystallites (12 and 16 nm in diameter) and investigated through the measurements of electric resistance and work function under different oxygen partial pressure. It was found that depletion in small crystallites of SnO₂ is characterized by the occurrence of new type depletion (volume depletion) after conventional one (regional depletion). In short, the relative resistance (R/R0) was proportional to P_O2^1/2 in volume depletion and the measurement of work function explained well the change of depletion state in regional depletion.

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金担持酸化スズゾルの水熱合成と
硫化水素検知特性におけるマイクロギャップ効果

立命館大生命

○橋新　剛、谷川　純也、玉置 純

HYDROTHERMAL SYNTHESIS OF AU LOADED TIN OXIDE SOL
AND EFFECT OF MICRO-GAP ELECTRODE
ON HYDROGEN SULFIDE SENSING PROPERTIES

Takeshi Hashishin, Junya Tanikawa, and Jun Tamaki

Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University,
Kusatsu-shi, Shiga 525-8577

The transparent pink sol solutions of Au-loaded SnO₂ were hydrothermally synthesized under different N₂ pressure. The solution of SnCl₄ was neutralized with NH₄HCO₃. The resulting precipitate was washed, filtrated, mixed with aqueous NH₃ (pH10.5), and hydrothermally treated at 200 ℃ for 5 h after the addition of HAuCl₄ aq. under various pressures of N₂ (0.9-10 MPa). The Au-loading was fixed at 2 wt%. The Au-SnO₂ solutions were dropped on the silicon substrate equipped with Au interdigitated electrode or the silica substrate equipped with Pt micro electrode with the gap size of 0.1 – 1 μm, dried, and calcined at 500 ℃ for 3 h to be Au-SnO₂ thin film gas sensors. It is very difficult to distinguish the difference between Au and SnO₂ nanoparticles by SEM observation because of the well-dispersed Au nanoparticles except Au aggregation. However, the sensor response of Au-SnO₂ to 1-3 ppm H₂S was higher than that of pure-SnO₂ suggesting the existence of Au component. The sensor response of Au-SnO₂ microsensor to 3 ppm H₂S was increased with the increase in the hydrothermal pressure of N₂ ranging from 0.9 to 10 MPa. Interestingly, the sensor response of Au-SnO₂ nanoparticles deposited on Pt electrodes was varied with decreasing gap size of Pt electrodes, depending on the existence state of Au nanoparticles between Pt electrodes.

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試料前処理ユニット一体化液体電極
プラズマ分光分析チップの開発

¹北陸先端大マテリアル，²マイクロエミッション

○熊谷哲成¹，北野厚志¹，中山慶子²，山本保²，高村禅¹

Development of Liquid Electrode Plasma-Optical Emission Spectrometry Chip Integrated with Pre-concentrator

N.Kumagai ¹, A.Kitano ¹, K.Nakayama ², T.Yamamoto ², Y.Takamura ¹

¹ School of Material Science in JAIST, ² Micro Emission Ltd.

Portable elemental analysis method is required in some kinds of environmental analysis such as water quality test, food-safety, on-site measurement in industry, and so on. Liquid Electrode Plasma–Optical Emission Spectrometry (LEP-OES) is elemental analysis method developed in our laboratory. This method has properties such as small size, low sample volume, and potential to be integrated with various sensors on a chip. In order to achieve a further detection limit, it is very effective to perform pre-concentration by Solid Phase Extraction (SPE) method. However, conventional SPE using columns take long time, and require a relatively large volume samples. In this paper, for the shortening of the preprocessing time of SPE, and for handy and prompt operation, the total integration chip with SPE and LEP are studied.

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ＣＣＤ型ナトリウムイオンイメージセンサの開発

豊技大物質^a，豊技大研究基盤セ^b，豊技大電気^c

○服部敏明^a，茂利智史^a，正木良知^a，加藤亮^b，澤田和明^c

DEVELOPMENT OF SODIUM ION IMAGE SENSOR
USING CHARGED COUPLED DEVICE TECHNOLOGY

Toshiaki Hattori ^a, Satoshi Mori ^a, Yoshitomo Masaki ^a, Ryo Kato ^b and Kazuaki Sawada ^c

^a Department of Materials Science, Toyohashi University of Technology,
Toyohashi 441-8580
^b Cooperative Research Facility Center, Toyohashi University of Technology,
Toyohashi 441-8580
^c Department of Electrical and Electronic Engineering, Toyohashi University of Technology,
Toyohashi 441-8580

We developed a new-type two-dimensional sodium ion image sensor with plasticized poly(vinyl chloride) (PVC) membrane, based on metal-oxide semiconductor and charged coupled device (CCD) technologies. The CCD sodium ion image sensor equipped 1024 (32x32) sensing pixels, which covered with plasticized PVC membrane. The membrane was prepared by a solution casting method. The cocktail contained bis(12-crown-4) as an ionophore of sodium ion, potassium tetrakis(4-chlorophenyl) borate as a cation exchanger, PVC as its membrane matrix, dioctyl phthalate as a plasticizer, and 1,3,5,7,9,11,13,15- Octa(propylmethacryl)pentacyclo- [9.5.1.1^3,9.1^5,15.1^7,13] octasiloxane as a nanofiller. The out-put signal of sensing pixels linearly increased with logarithmic concentration of sodium ion from 10^-5 M to 10^-2 M. The selectivity coefficients of other alkaline metal ions were less than one percent. The CCD sodium ion image sensor displayed real-time images of sodium ion concentration, and can dynamically monitor instant changes of sodium ion concentration.

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アレイ状光源を用いた小型化学イメージセンサの開発

東北大工^a、東北大医工^b

金子 一美^b, 松尾 顕^a, ○宮本 浩一郎^a, Wagner Torsten ^b, 加納 慎一郎^a, 吉信 達夫^a,b

DEVELOPMENT OF A MINITUALIZED CHEMICAL IMAGING SENSOR SYSTEM　USING SMALL DISPLAY PANEL

Kazumi Kaneko ^b, Akira Matsuo ^a, Ko-ichiro Miyamoto ^a, Torsten Wagner ^b,
Shinichiro Kanoh ^a and Tatsuo Yoshinobu <sup>a,b

a</sup> Department of Electronic Engineering, Tohoku Univ.
^b Department of Biomedical Engineering , Tohoku Univ.
6-6-05 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan

Chemical sensors which detect chemical species in the specimen are important for industrial and medical applications. The chemical imaging sensor, which is based on light-addressable potentiometric sensor (LAPS), visualizes the two-dimensional distribution of chemical species as a chemical image. Although the sensor can be applied for bio-chemical or electrochemical phenomena, a problem of an expensive and large system still remains due to its focusing optics and the mechanical scan of the laser beam. Therefore, a smaller light source unit without the need of additional optics and mechanical parts has been desired. In this study, we propose a hand-held chemical imaging sensor system using a small display panel as a light source. Light spots are defined by the blinking pixels on the organic LED display. By changing the pixel pattern and the position of the light spot on the display panel, the measurement area and the resolution can be flexibly selected. The photocurrent - bias voltage characteristics of the sensor plate and the results of chemical imaging are reported.

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コバルト応答型アルカリホスファターゼの作製とセンサへの応用

神奈川工科大工　^a応用バイオ科学科、^b応用化学科

野島大佑^b、佐藤生男^b、○飯田泰広^a

Development of Cobalt Responsive Alkaline Phosphatase
and Application of the Enzyme to Biosensing as a Recognition Element

Daisuke NOJIMA ^b, Ikuo SATOH ^b and Yasuhiro IIDA ^a

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

Development of cobalt (II) ion responsive recombinant alkaline phosphatase and determination of cobalt (II) ions with use of the immobilized recombinant in combination with spectrophotometric flow injection analysis were investigated in this study. The histidine residue at position 334 of alkaline phosphatase (ALP, a kind of typical metalloenzymes (zinc-enzymes)) was genetically modified to tryptophan (H334W) to respond to cobalt (II) ions as a cofactor of the enzyme. The vector of the modified recombinant ALP gene was transfected to tobacco culture cells (BY-2) by using Agrobacterium mediated transformation. The recombinant ALP was covalently immobilized onto gold mesh and then, packed into a small polymer column. The column was introduced into FIA system which was assembled with a double plunger pump, rotary injection valve with sample loop, the column and a flow injection photometric device. The catalytic activity of the enzyme column was assessed by injecting 0.1 ml of 1.0 mM p-nitrophenyl phosphate (pH 8.0) as a substrate. Removal of cobalt (II) ions from the enzymes was positively made by injecting PDC (2,6-pyridine dicarboxylate) as a chelating agent. When the substrate solution was injected to the once PDC treated column, absorbance at 405 nm in the effluents from the enzyme column decreased significantly. The enzyme activity of the column was sufficiently recovered by injecting 1.0 mM standard cobalt(II) ions. Reversible changes in the enzyme activity between the regeneration and reactivation processes could be observed repeatedly. Thus, determination of cobalt (II) ions in micromolar levels was demonstrated.

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ロジウムフタロシアニン触媒を利用したシュウ酸センサの研究開発

産業技術総合研究所

○山崎 眞一、藤原 直子、八尾 勝、妹尾 博、安田 和明

DEVELOPMENT OF RH PHTHALOCYANINE CATALYSTS
FOR AN OXALIC ACID SENSOR.

Shin-ichi YAMAZAKI, Naoko FUJIWARA, Masaru YAO,
Hiroshi SENOH, Kazuaki YASUDA

Research Institute for Ubiquitous Energy Devices,
National Institute of Advanced Industrial Science and Technology (AIST),
1-8-31 Midorigaoka, Ikeda, Osaka 563-8577

It was demonstrated that a rhodium phthalocyanine complex exhibit high electro-catalytic activity toward oxalic acid oxidation. The onset potential for the oxidation of oxalic acid is much lower than those of conventional electrodes such as platinum electrodes or carbon-based electrodes. The current density was much higher than those of Rh porphyrins. The substrate specificity and the inhibitory effect of anion were also examined. The results suggest that carboxyl group of oxalic acid first coordinate to the Rh atom in the reaction. An amperometric sensor for oxalic acid was fabricated using Rh phthalocyanine. The limit of detection of the sensor reached 1μM; the value compares with those of other sensors. The working potential of this sensor (0.75 V vs. a reversible hydrogen electrode) was much lower than other non-enzymatic oxalic acid sensors.

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抗体固定化FETを利用した
腫瘍マーカーの定量検出（1）FET応答の安定化

早大院先進理工^a、早大科健機構^b

○秀島 翔^a、佐藤 涼介^a、黒岩 繁樹^b、逢坂 哲彌^a

QUANTITATIVE DETECTION OF A TUMOR MARKER
USING AN ANTIBODY-MODIFIED FET (1) – STABILIZATION OF FET RESPONSE

Sho HIDESHIMA ^a, Ryosuke SATO ^a, Shigeki KUROIWA ^b and Tetsuya OSAKA ^a

^a Graduate School of Advanced Science and Engineering, Waseda University,
Shinjuku, Tokyo 169-8555
^b Institute for Biomedical Engineering, Waseda University,
Shinjuku, Tokyo 162-0041

The ability to rapidly sense a tiny amount of biomolecules is critical for clinical diagnostics, genomics, and drug discovery, which is useful for applications in health care. Field effect transistor (FET) is a promising biosensing device for detecting a trace of biomolecules with high sensitivity and rapidity. The application of FET to biosensing in clinic diagnoses has been facing significant challenge because the reproducibility and sensitivity are not high enough to determine the amount of biomolecules accurately. Voltage application in detecting biomolecules causes the desorption of biomolecules on FET gate surface, which reduces the reproducibility and the sensitivity. Here we propose a stable antibody-modified surface fabrication method to prevent antibody desorption on the FET surface by activating a cross-linker, glutaraldehyde (GA) on the surface using electric application. We demonstrate that this stable antibody-modified FET could quantitatively detect a tumor maker, human chorionic gonadotropin (hCG). This method will improve the reproducibility and sensitivity of FET-based biomolecular detection.

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抗体固定化FETを利用した
腫瘍マーカーの定量検出（2）夾雑タンパク質の影響

早大院先進理工^a、早大科健機構^b

○佐藤 涼介^a、秀島 翔^a、黒岩 繁樹^b、逢坂 哲彌^a

QUANTITATIVE DETECTION OF A TUMOR MARKER
USING AN ANTIBODY-MODIFIED FET (2) – EFFECT OF CONTAMINATING PROTEINS

Ryosuke SATO ^a, Sho HIDESHIMA ^a, Shigeki KUROIWA ^b and Tetsuya OSAKA ^a

^a Graduate School of Advanced Science and Engineering, Waseda University,
Shinjuku, Tokyo 169-8555
^b Institute for Biomedical Engineering, Waseda University, Shinjuku, Tokyo 162-0041

Highly sensitive, rapid and simple analysis of proteins is central to clinical diagnosis, gene sequencing and drug discovery. Field effect transistor (FET) devices have considerable promise as electronic transducers for rapid and highly sensitive detection of biorecognition events. In the application of FET biosensors in medical fields, detecting quantitatively a tumor marker in serum saves extra steps for sample preparation. Therefore, detection of target proteins in contaminating proteins is important. However, there is a possibility that the charges of contaminating proteins adsorbed on the gate area lower the quantitativity of FET detection. We have developed stable antibody-modified FET for tumor marker detection. In this study, quantitative detection of a liver cancer marker, α-fetoprotein (AFP), using an anti-AFP antibody-modified FET was performed. The effect of contaminating proteins on detection of AFP was also evaluated. We demonstrated that this developed anti-AFP antibody-modified FET had quantitative capability for AFP detection and the detection limit of AFP was 10 ng/mL. Also, detection of 1 μg/mL AFP in the presence of contaminating proteins was achieved.

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スクリーン印刷型光合成活性測定型
藻類細胞バイオセンサの作製条件の検討と長期安定性評価

東理大理工

○寺田　早紀，四反田　功，板垣　昌幸，渡辺　邦洋

INVESTIGATION OF FABRICATION CONDITION AND STORAGE STABILITY OF
AMPEROMETRIC SCREEN-PRINTED ALGAL BIOSENSOR

Saki TERADA, Isao SHITANDA, Masayuki ITAGAKI, Kunihiro WATANABE
Department of Pure and Applied Chemistry, Faculty of Science, Tokyo University of Science Noda,
Chiba 278-8510, Japan

In the present study, fabrication condition and storage stability of a screen-printed algal biosensor was investigated. Algal inks were prepared by changing in the composition ratio of the algal cells, multiwall carbon nanotube and sodium alginate solution. The algal inks were printed on the carbon electrode surface by screen printing. The printed electrode was immersed in 0.2 M CaCl₂ solution for gelation. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. The response of the algal biosensor improved in comparison with the algal biosensor previously reported. The algal biosensor stored for 9 weeks in 0.2 M CaCl₂ solution at 4℃ retained about 80% of its photosynthetic activity. The concentrations that gave 50% inhibition of the oxgen reduction current (IC₅₀) for a toxic compound, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine), was 14 μM when the algal biosensor after 6 weeks was used.

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韓国絶縁油中PCBのスクリーニングを目的とした
PCBバイオセンサーの構築と評価

電中研^a、韓国電力研究院^b

○寺門 真吾^a、大村 直也^a、Seok-Un Park ^b、Seung-Min Lee ^b

DEVELOPMENT OF A PCB BIOSENSOR BASED ON IMMUNOASSAY TO SCREN PCBS
OF TRANSFORMER OIL IN KOREA

Shingo Terakado ^a, Naoya Ohmura ^a, Seok-Un Park ^b and Seung-Min Lee ^b
a Central Research Institute of Electric Power Industry,
1646 Abiko, Abiko-shi, Chiba 270-1194 Japan
^b Korea Electric Power Research Institute,
65 Munji-Ro, Yuseong-Gu, Daejeon 305-760 Korea

A lot of PCB contaminated transformers are still in service around the world including in Korea. Therefore, a PCB biosensor which we had developed previously attracted attention in Korea because it can measure Kaneclors (Japanese commercial PCB mixtures) in oil rapidly and cheaply. In this study, we developed a new antibody, designated OD8B11, to measure Aroclors that were used in Korean transformer oil. Compared to the antibody used in Japan, the new antibody binds Aroclors tightly and shows nearly equal reactivity towards the four kinds of Aroclors. Conditions for applying the OD8B11 antibody on the PCB biosensor platform, such as antibody concentration, flow volume, and flow rate were optimized. Under the optimized conditions, the PCB biosensor can detect Aroclor in mineral oil in the range from 0.2 ppm to 8 ppm. In the range, correlation between HRGC/HRMS and the PCB biosensor were 0.97 and the slope of the linear correlation was 1.02. Furthermore, among 79 samples supplied by KEPRI, the PCB biosensor was able to correctly screen 59 samples. We attribute measurement problems with the remaining 20 samples to turbidly apparent after the PCB biosensor pretreatment.

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自己組織化単分子膜を用いた参照用FETの
イオン応答への表面モルフォロジーの効果

早大科健機構^a、早大院先進理工^b

○黒岩 繁樹^a，柴崎友美^b，逢坂 哲彌^b

MORPHOLOGICAL EFFECT ON IONIC RESPONSES OF REFERENCE FIELD EFFECT TRANSISTOR MODIFIED BY SELF-ASSEMBLED MONOLAYER

Shigeki KUROIWA ^a, Tomomi SHIBASAKI ^b, and Tetsuya OSAKA <sup>b

a</sup> Institute for Biomedical Engineering, Waseda University,
Shinjuku, Tokyo 162-0041
^b Graduate School of Advanced Science and Engineering, Waseda University,
Shinjuku, Tokyo 169-8555

For completion of in vivo-applicable on-chip field effect transistor (FET) biosensors, it is essential to produce a reference FET instead of a reference electrode that uses an inner electrolyte. To fabricate a reference FET, the gate surface of FET was modified with the self-assembled monolayer (SAM) of n-octadecyltrimethoxysilane (ODS). Though an ODS-SAM FET had low pH-sensitivity, it was cation-sensitive as was reported in polymer-gate FETs. This work demonstrates the relation between the surface morphology and the cationic and pH-sensitivity of ODS-SAM FETs. Our purpose was establishment of chemical vapor deposition (CVD) of ODS on an FET to fabricate a cation- and pH-insensitive reference FET. ODS-SAM FETs were deposited under different CVD condition (additive amount of ODS and processing time). pH and ionic responses were changed by the difference in morphology of the ODS-SAM. A roughness parameter of atomic force microscope (AFM) images, the mean summit curvature (Ssc) has correlation with the cationic and pH-sensitivity of ODS-SAM FETs. Controlling the surface morphology of the ODS-SAM is important to suppress the pH and ionic sensitivities.

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細胞膜モデルを用いた環境化学物質センサ

創価大工

○中根優子、久保いづみ

A SENSOR OF ENVIRONMENTAL CHEMICALS UTILIZING MODELS
OF CELL MEMBRANE

Yuko NAKANE and Izumi KUBO

Department of Bioinfomatics, Faculty of Engineering, Soka University,
Hachioji, Tokyo, 192-8577

Environmental chemicals are produced by our industrial activity and concerned with health hazard like endocrine disruptors. Universal sensing methods are required for assessment of the chemicals and their risk. In this study, a sensing system for the chemicals based on their common property, invading to intracellular space by passing through cell membrane was investigated. At first, we prepared an assembly composed from cell membrane protein and liposome as a model of cell membrane and immobilized the assembly on quartz crystal microbalance (QCM). The fabricated sensor detected 1.0 ppb- 1.0 ppm nonylphenol, which is one of environmental chemicals. Then, we used only liposome as a model of cell membrane and prepared liposome capsulating fluorescence dye. When the liposome was exposed to the chemicals, fluorescence intensity was significantly increased.

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熊本大院工

○西山勝彦、甲斐亜希子、稲田和文

High Sensitive Carbon Paste Electrodes for Detection of Bio-related Materials

Katsuhiko NISHIYAMA, Akiko KAI, and Kazufumi INADA

Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University,2-39-1, Kurokami, Kumamoto 860-8555

So far, we demonstrated that voltammetric determination of tryptophan (Trp) and serotonin (5-HT) was successfully detected by analyzing the redox peaks of their oxidation products at glassy carbon paste electrodes (GCPEs) in phosphate buffer solutions in the presence of interferences. However, the sensitivity for 5-HT was not enough for accurate determination. Here, we will report on the effect of electrochemical oxidation on the sensitivity 5-HT as well as Trp. By the potential cycle from 0 to 1.5 V for one time, The oxidation current for the detection of Trp became twice at GCPEs and the current response for 5-HT became eight times at GCPE containing sodium polystyrene sulfonate.

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スクリーン印刷金電極を用いるフェニルアラニンセンサの開発

富山大院理工^a、富山県立大工^b

○堀江 肇^a、篠原 寛明^a、須加 実^a、浅野泰久^b

DEVELOPMENT OF A PHENYLALANINE SENSOR
USING A DISPOSABLE ENZYME ELECTRODE CHIP

Hajime Horie ^a, Hiroaki Shinohara ^a, Minoru Suga ^a, Yasuhisa Asano ^b

^a Graduate School of Science and Engineering, University of Toyama,
3190 Gofuku, Toyama 930-8555
^b Biotechnology Research Center, Toyama Prefectural University,
5180 Kurosawa, Imizu, Toyama 939-0398

Phenylalanine (Phe) is an important essential amino acid and a biomarker of phenylketonuria. Though Phe is usually detected by the analysis using high performance liquid chromatography (HPLC) with post-column labeling as same as other amino acids, this method is timeconsuming and its operation is not so easy. Therefore the development of shorter and easier analytical methods for detection of Phe is requested. For this purpose, we have previously developed a Phe sensor with a gold disk electrode on which phenylalanine dehydrogenase (PheDH) and diaphorase (DI) were co-immobilized. In this study, a disposable enzyme electrode chip was prepared for the health-care of phenylketonuria with a screen-printed gold electrode for detection of Phe. CV measurement with the developed bi-enzyme sensor chip demonstrated the increase of the catalytic oxidation current related to the concentration of Phe. This sensor showed high selectivity for phenylalanine and detection range from 10 to 100 µM. This sensor will be applied to the phenylalanine monitoring of blood samples.

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BMIに用いる脳波測定用電極の開発

国立障害者リハビリテーションセンター研究所 生体工学研究室^a
国立障害者リハビリテーションセンター研究所 感覚認知障害研究室^b

○外山 滋^a、　高野 弘二^b、池上 史郎^b、神作 憲司^b

DEVELOPMENT OF ELECTRODES TO DETECT BRAINWAVES FOR THE USE OF BRAIN MACHINE INTERFACES

Shigeru TOYAMA ^a, Kouji TAKANO ^b, Shiro IKEGAMI ^b, and Kenji KANSAKU ^b

^a Biotechnological Rehabilitation Section, Research Institute,
National Rehabilitation Center for Persons with Disabilities,
4-1 Namiki, Tokorozawa 359-8555
^b Cognitive Functions Sectionb, Research Institute,
National Rehabilitation Center for Persons with Disabilities,
4-1 Namiki, Tokorozawa 359-8555

Several electrodes using conductive materials to detect brainwaves for the use of Brain Machine Interface (BMI) have been developed. Among them, the electrode with a conductive gel consisting of carboxymethyl celrose and calcium chloride exhibited desirable characteristics. The gel showed superior conductivity, wettability, and elasticity. The gel attached on the head skin by penetrating through the hair when the gel-loaded electrode was pressured on a head, due to its elasticity. The impedance-check certified the usefulness of the electrodes for BMI use. Furthermore, we could measure brain waves such as alfa-wave with this electrode.

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分子インプリント高分子のゲート効果における選択性と複合体形成能の関係

芝浦工大応用化学科

○吉見 靖男, 川名 雅仁, 安藤 寛之

RELATIONSHIP BETWEEN THE STABILITY OF THE TEMPLATE/MONOMER COMPLEX AND SELECTIVITY OF THE GATE EFFECT OF MOLECULARLY IMPRINTED POLYMER

Yasuo Yoshimi, Masahito Kawana, Hiroyuki Ando

Dept. Applied Chemistry, Shibaura Institute of Technology,
3-7-5 Toyosu Koto-ku Tokyo 135-8548, JAPAN

The affinity between the template and the functional monomer is one of the most important factors in molecular imprinting. The purpose of this study is speculating the relationship between the affinity and gate effect of molecularly imprinted polymer (MIP). The phenylalanine anilide (PAA) with methacrylic acid (MAA) was analyzed by NMR. The peak of the primary amine of PAA shifted by the presence of MAA. The degree of the shift increased with the increase of MAA. A MIP was grafted on indium-tin oxide (ITO) using with L- (or D-) PAA as a template and MAA as a functional monomer. Cyclic voltammetry was performed using the MIP-grafted ITO as a working electrode. However, the selectivity does not increased with the value of [MAA]/[PAA] in the monomer solution. The discrepancy may be caused by the interaction between the template and the crosslinker which was the main component.

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過酸化ポリピロールを用いるペプチドセンサの開発

阪府大産学官

床波 志保，溝畑 裕巳，椎木 弘，○長岡 勉

DEVELOPMENT OF PEPTIDE SENSORS USING
AN OVEROXIDIZED POLYPYRROL FILM

Shiho TOKONAMI, Yuhki MIZOHATA, Hiroshi SHIIGI, Tsutomu NAGAOKA

FSIC, Osaka Prefecture University,
1-2 Gakuen-cho, Sakai, Osaka, 599-8570

We have developed a quartz microbalance sensor based on molecularly imprinted polymer, which allows the discrimination of modified and unmodified peptides. The molecularly imprinted polymer was prepared by electrochemical overoxidation of polypyrrole, which doped phosphate as a template. The sensor was fabricated on a gold-coated quartz micorbalance sensor, and the uptake and release of the peptides were monitored by the repeated perturbation cycles of the potential. The selectivity of the film for the phosphate-modified peptide was about four times as high as that for the unmodified peptide.

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エピジェネティクス計測評価チップの研究開発（I）
DNAメチル化分離アッセイの基礎検討

産総研健康工学^a、産総研計測標準^b、産総研生物機能工学^c

○脇田 慎一^a、宮道 隆^a、藤井 紳一郎^b、高津 章子^b、加藤 大^c、丹羽 修^c

R & D OF BIOCHIP FOR EPIGENETICS（Ⅰ）
BASIC STUDY ON ON-CHIP SEPARATION OF DNA METHYLATION

Shin-ichi WAKIDA ^a, Takashi MIYADO ^a, Shin-ichiro FUJII ^b,
Akiko TAKATSU ^b, Dai KATO ^c and Osamu NIWA ^c

^a Health Technology Research Center,
National Institute of Advanced Industrial Science and Technology (AIST),
Midorigaoka 1-8-31, Ikeda, Osaka 563-8577
^b National Metrology Institute of Japan (NMIJ),
National Institute of Advanced Industrial Science and Technology (AIST),
Umezono 1-1-1, Tsukuba, Ibaragi 305-8563
^c Institute for Biological Resources and Functions,
National Institute of Advanced Industrial Science and Technology (AIST),
Higashi 1-1-1, Tsukuba, Ibaragi 305-8566

Cytosine methylation is one of the well-known epigenetic mechanisms. It has been reported that several cancers may be closely associated with changes in cytosine methylation. In particular, the degree of cytosine methylation of a specific gene can be important in the development of cancer. The final goal of this study is the development of a high-throughput measurement for the degree of cytosine methylation using a microfluidic device system based on capillary electrophoresis and electrochemical detection. In this paper, to develop the on-chip assay, the basic study on running buffers using capillary electrophoresis (CE) was described. Using the AMP buffer reported, the complete CE separation of dCMP, mdCMP and dTMP was achieved, however, the separation windows was not enough in case of microchip electrophoresis (MCE). Therefore, the other running buffers were studied. Among the several running buffer, Tris-HCl and phosphate buffers resulted in the relatively good separation windows of dCMP and dTMP were obtained. Moreover, preliminary results of on-chip MCE separation will be reported.

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酵素前駆体（組換えFactor C）を利用するエンドトキシンの
電気化学測定法の検討

東北大院環境

○井上（安田）久美，　伊野 浩介，　珠玖 仁，　末永 智一

ELECTROCHEMICAL DETECTION FOR ENDOTOXIN
USING RECOMBINANT LIMULUS FACTOR C

Kumi Y. INOUE, Kosuke INO, Hitoshi SHIKU and Tomokazu MATSUE

Graduate School of Environmental Studies, Tohoku University,
6-6-11 Aoba, Aramaki, Aoba, Sendai 980-8579, Japan

We have developed an electrochemical sensor for endotoxin, a pyrogen which potentially provokes innate immune responses that induce septic shock. In the present study, we have used recombinant limulus factor C (rFC) developed by Ding et al as a sensing element. rFC is a protease zymogen activated by endotoxin to cleave a synthetic substrate resulting in generation of an electrochemical active compound of p-nitroanilne (pNA).　The liberated pNA was detected by differential pulse voltammetry (DPV) at - 0.75 V. We could detect 5,000 EU/L and 1,000 EU/L of endotoxin for 1hr and 3hr reaction time, respectively, in the Tris-Ac buffer pH 7.5 at 37 ℃.

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先端内部をセンシング部位とする
低侵襲型グルコースセンサの試作およびその評価

徳島大院ソシオテクノサイエンス

○安澤 幹人、西村 勇哉、枝川 和明、高岡 宏樹

Preparation and Evaluation of a Low Invasive Glucose Sensor

Mikito YASUZAWA, Yuya NISHIMURA, Kazuaki EDAGAWA and Hiroki TAKAOKA

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

A unique needle type glucose sensor having sensing region inside the tip of a fine tube was fabricated using a sharpen platinum tube. The enzyme glucose oxidase was immobilized on the platinum surface located inside the tip of a fine tube by two step. Firstly, formation of the enzyme monolayer by the electrodeposition of enzyme in the presence of Triton-X, and secondary, electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current at a potential of 0.60 V (for hydrogen peroxide detection) in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). The obtained sensor showed good response with good linear relationship with glucose concentration up to 18 mmol dm-3. Although the influence of ascorbic acid and acetaminophen to the glucose response current were relatively low, the influence of uric acid was not neglectable.

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電気化学発光を利用した酵素免疫測定法

産総研^a、筑波大^b

○栗田僚二^a、新井久美^a、中元浩平^a,b、加藤大^a、丹羽修^a,b

ELECTROGENERATED CHEMILUMINESCENCE BASED
ENZYME-LINKED IMMUNOSORBENT ASSAY

Ryoji KURITA ^a, Kumi ARAI ^a, Kohei NAKAMOTO ^a,b, Dai KATO ^a and Osamu Niwa ^a,b

^a National Institute of Advanced Industrial Science and Technology (AIST)
Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566
^b University of Tsukuba,
1-1-1 Tennoudai, Tsukuba 305-8573

We report the development and characterization of highly sensitive enzyme linked immunosorbent assay that is realized by an electrogenerated chemiluminescence (ECL) detection of a thiol monolayer formed by the enzyme labeled antibody. We used two monoclonal anti tumor necrosis factor-α (TNF-α) antibodies for sandwich immunoassay. One is a capture antibody, and the other is a detection antibody labeled with an enzyme via an avidin-biotin interaction. Acetylcholinesterase was used as the labeling enzyme to convert acetylthiocholine to thiocholine. Then the thiocholine was collected on a gold electrode surface by a gold -thiol binding. Bright and distinctive emission was observed at 1150 mV (vs. Ag-AgCl) on the gold electrode with a thiocholine monolayer as a coreactant in the presence of tris(2,2′-bipyridyl)ruthenium complex. This method can greatly enhance the signal of immunoassay since a large amount of coreactant molecules can be generated by the enzymatic reaction, which is advantageous compared to previously reported ECL based immunoassay which directly labels coreactant or luminophore to the detection antibody. In addition, surface accumulated coreactant is advantageous compare to previous coreactant system in a bulk solution because electrogenerated chemiluminescence emission takes place only very close to an electrode surface. As a result, high sensitivity and a low detection limit of TNF-α were achieved with excellent reproducibility by optimizing the conditions of immuno-reaction, thiocholine accumulation and generation of ECL.

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妨害物質除去のためのウェーブレット変換による
バイオセンサの応答波形解析

東理大理工

○田中　沙織，四反田　功，板垣　昌幸，渡辺　邦洋

WAVELET TRANSFORMATION ANALYSES OF AMPEROMETRIC BIOSENSOR RESPONSE FOR ELIMINATION INTERFERING SUBSTANCE

Saori TANAKA, Isao SHITANDA, Masayuki ITAGAKI, Kunihiro WATANABE

Department of Pure and Applied Chemistry, Faculty of Science, Tokyo University of Science
Noda, Chiba 278-8510, Japan

It is important that elimination of interfering substances for high sensitive biosensor. The wavelet transformation (WT) has been shown a powerful tool for the deconvolution of the electrochemical signals. In the present study, the WT is applied for an amperometric glucose biosensor response. Ascorbic acid is used as the model interfering substance. It was proved that the current response due to ascorbic acid was clearly removed by using WT.

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SIGNAL ENHANCEMENT OF TYROSINASE-BASED
ELECTROCHEMICAL FLOW BIOSENSOR BY ACRIDINE ORANGE

○Yue WANG ^a,b and Yasushi HASEBE ^a,c

^a Department of Materials Science and Engineering, Graduate School of Engineering,
Saitama Institute of Technology, Fukaya-shi, Saitama 369-0293, Japan
^b School of Chemical Engineering, University of Science and Technology Liaoning,
Anshan, Liaoning , 114044, China
^c Department of Life Science and Green Chemistry, Saitama Institute of Technology,
Fukaya-shi, Saitama 369-0293, Japan

Tyrosinase (TYR: EC 1.14.18.1) was covalently modified onto a cyanuric chloride (CC)-activated carbon felt (CF). The resulting TYR-immobilized CF was utilized as an electrochemical flow detector for phenol and catechol compounds which detects the reduction current of o-quinones produced by the TYR reaction. When TYR was immobilized from a mixed solution of TYR and acridine orange (AO), the peak current responses of five substrates (i.e., catechol, dopamine, p-chlorophenol, p-cresol, phenol) were enhanced as compared with the case without AO. The degree of signal enhancement factor (the ratio of the sensitivity) was in the order of phenol > p-chlorophenol > p-cresol > dopamine > catechol. As a result, the sensitivity of phenol compounds was much superior to our previous study on immobilized TYR onto amino-functionalized CF using various cross-linking reagents1). The measurement of the rate of oxygen consumption in TYR solution revealed that the monophenolase activity of TYR was greatly enhanced in the presence of AO, suggesting the interaction between AO and TYR leading to the change of the catalytic activity of TYR.

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マイクロコンタクトプリンティングによる
極微小アセチルコリンセンサアレイの作製

富山大院理工

川淵　貴史，○鈴木　正康

MICRO ACETYLCHOLINE SENSOR ARRAY PREPARED
BY USING MICROCONTACT PRINTING

Takafumi KAWABUCHI and Masayasu SUZUKI

Faculty of Engineering, University of Toyama,
Toyama-shi, Toyama 930-8555

We have already developed the integrated optical pH and oxygen sensor array by using microcontact double printing. In this study, acetylcholine sensor array was prepared by using microcontact printing. Firstly, acetylcholinesterase (AChE) was stamped onto FITC-based pH sensor array. But the response was quite slow because of low diffusion coefficient of H⁺ ion. In order to decrease the distance between enzyme molecules and FITC, enzyme was directly modified with FITC and the FITC modified AChE was immobilized onto an aminated glass slide. Although the response rate was remarkably improved, only little response could be observed. This might be caused by the decrease of enzyme activity caused by FITC modification. In order to solve this problem, the mixture of AChE enzyme and FITC modified bovine serum albumin (FITC-BSA) was used as the ink. The protein mixture was stamped onto glutaraldehyde-activated aminated glass slide, then the proteins were crosslinked under glutaraldehyde atmosphere. Averaged diameter of sensor spots was 13.48±0.87micron (n=25). Acetylcholine between 0.002 and 1 mM could be determined by this sensor array. Since acetylcholine is a typical neurotransmitter, this sensor array might be powerful tool for fluorescent chemical imaging for functional analysis of neuron synapses.

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ダイアフラムポンプ一体化型抗原抗体反応検出チップの開発

JAIST ¹、阪大院工²

○元古 義隆¹、塩原　秀¹、近江 みゆき¹、民谷 栄一²、高村　禅¹

Detection Chip for Antigen-Antibody Reaction Integrated with Diaphragm Pump

○ Yoshitaka Genko ¹, Suguru Shiohara ¹, Miyuki Chikae ¹, Eiichi Tamiya², Yuzuru Takamura ¹

¹ School of Materials Science, ² Advanced Institute of Science and Technology,
Osaka University

On the fields of daily health-management and medical diagnoses, detections of the biomarkers which indicate health condition are important. Variety of methods that detects biomarkers related for diseases have been already studied. We focused on the electrochemical measurements from the viewpoints of system-downsizing, cost performance, and easy-operation. Almost commercial available biosensors only detect biomarkers that exist in human blood with comparatively high concentration. The objective of this study is to automate washing process to detect antigen antibody reactions. The pump-integrated biosensor consists of the air layer and the flow layer made of PDMS (poly-dimethylsiloxane). The pumping principle is as follows. When the air line is depressurized, the inlet valve opens, and the liquid is sucked from inlet into the middle chamber. Next, the air line is pressurized, inlet valve closes, then the membrane pushes the liquid to outlet through the check valve. We use this pump then we check up behavior of the pump and applying for DEP-chip. We succeed to automation of washing process.

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イムノクロマト法を用いたインフルエンザウイルスRNAの検出法

岡山理大工^a、阪大院工^b、（有）バイオデバイステクノロジー^c

○永谷 尚紀^a、前田 元喜^a、山中 啓一朗^b、斉藤 真人^b、由比 光子^c、
牛島 ひろみ^c、民谷 栄一^b、宮原 敏郎^a

DETECTION OF INFLUENZA VIRUS RNA USING IMMUNOCHROMATOGRAPHIC ASSAY

Naoki NAGATANI ^a, Genki MAEDA ^a, Keiichiro YAMANAKA ^b, Masato SAITO ^b, Teruko YUHI ^c,
Hiromi USHIJIMA ^c, Eiichi TAMIYA ^b and Toshiro MIYAHARA <sup>a

a</sup> Department of Applied Chemistry, Faculty of Engineering, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005
^b Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871
^cBiodevicetechnology Ltd., 2-13 Asahidai, Nomi-City, Ishikawa 923-1211

The swine influenza keeps spreading to all over the world. Rapid diagnostic kits based on immunochromatographic assay utilizing antigen-antibody reaction for the influenza virus are commercially available. The sensitivity of the rapid diagnostic kits, however, is usually low compared with that of genetic assays. We have developed an immunochromatographic assay for the detection of influenza virus RNA amplified by reverse transcription polymerase chain reaction (RT-PCR). As a result, two types influenza virus RNA (A/H3N2 and A/H1N1), were amplified by RT-PCR using biotin-labeled primer and fluoresceinisothiocyanate (FITC)-labeled primer. The amplified influenza virus RNA and gold nanoparticles conjugated anti-biotin antibodies were mixed, and the mixture was absorbed by capillary action in the immunochromatograpphic test strip immobilizing anti-FITC antibodies. The red color caused by the accumulation of gold nanoparticles was observed at test line (positive) within 1 minute. This immunochromatographic assay for the detection of the amplified RNA would be useful as rapid and simple screening method when RNA can be amplified by a rapid amplified system like a biochip.

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ナノホール構造を用いたプラズモンセンサの作製とバイオセンシングへの応用

筑波大数理物質科学^a、産総研生物機能^b

○中元 浩平^a,b、栗田 僚二^b、 丹羽 修^a,b

FABRICATION OF AN ON-CHIP AFFINITY BIOSENSOR
BY INTEGRATING A NANOHOLE ARRAY SURFACE PLASMON RESONANCE METHOD
FOR REAL-TIME BIOCHEMICAL MEASUREMENT APPLICATIONS

Kohei NAKAMOTO ^a,b Ryoji KURITA ^b and Osamu NIWA ^a,b

^a Graduate School of Pure and Applied Science , University of Tsukuba,
1-1-1 Tennodai, Tsukuba 305-8573
^b National institute of Advanced Industrial Science and Technology (AIST),
Central 6, 1-1-1 Higashi, Tsukuba 305-8566

We have developed a polydimethylsiloxane (PDMS) based microfluidic device for a biomolecular affinity sensor based on grating based surface plasmon resonance (SPR). We fabricated surfaces with various configurations, which reveals a clear relationship between the pitch length and the SPR peak wavelength sensitivity and between the optimal hole depth and the width of the peak of the reflection spectra. We found that both the peak wavelength and the sensitivity increased with the array pitch length. In addition, it was found that the sharpest peak spectrum was obtained with a nanohole depth of 50 nm. As a result, a nanohole array with a diameter of 300 nm, a pitch of 600 nm, and a depth of 50 nm is suitable for improving sensitivity and resolution for bio-analysis. Reflection spectra show that the wavelength shift of bovine serum albumin (BSA) adsorption is similar to that due to biomolecular interactions between biotin and streptavidin-Au even though an only small amount of streptavidin-Au is present. This could be because the Au nanoparticles proximity to the gold nanohole array enhances the signal. This result encourages us to apply our method to obtain highly sensitive immunoassays.

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分析装置の新展開
～マイクロ化技術の実用化と課題

島津製作所基盤研^a、奈良先端大^b

○西本尚弘^a,b

EVOLUTIONAL CHANGE OF ANALYTICAL INSTRUMENTS - CHALLENGES FOR PRACTICAL USE OF MICRO-TAS

Takahiro NISHIMOTO ^a,b

^a Technology Research Laboratory, Shimadzu Corporation,
3-9-4 Hikaridai, Seika-cho, Kyoto 619-0232
^b Nara Institute of Science and Technology

As an example of MEMS-based analytical instrumentation, a high performance chip column for gas chromatography fabricated on a silicon wafer was developed. Experimental results of the chip column are described. Approximately 35000 theoretical plates were generated with the chip column coated with liquid phase (5% phenyl-/95% dimethyl-polysiloxane). The theoretical plates of the chip column were close to those of the capillary column. We also developed a plasma ionization detector in which a micro-plasma technology is utilized. LF(Low Frequency) helium plasma is a stable excitation source suitable for high-sensitive gas detector.

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繰り返し法と拡散抑制による金ナノ粒子標識電気化学免疫測定法の高感度化

北陸先端大・マテ¹, 大阪大・工²

○塩原秀¹, 井手上公太郎¹, 近江みゆき¹,民谷栄一², 高村禅¹

Cyclic property and diffusion control effect in gold linked electrochemical immunoassay

S. Shiohara ¹, K. Idegami ¹, M. Chikae ¹, E. Tamiya ², and Y. Takamura ¹

¹ JAIST,
² Osaka Univ

In order to develop devices aiming to be utilized in daily health-managements, and also to build integrated medical diagnosis systems, the detection of the biomarkers which indicates health condition is important. Up to date, variety of methods that detect biomarkers related for diseases already has been studied. We focused on the electrochemical measurement from the viewpoints of system-downsizing, cost performance, easy–operation, and point of care. Most of commercial available biosensors can detect the biomarkers only with high concentration in human blood. If easy-measurement method for low concentration biomarkers (ex, hormone) will be developed, application fields of this method expected to be broaden. Thus, we developed GLEIA (gold liked electrochemical immunoassay) whose principle is as follows. At first, antibody is fixed on a carbon electrode. Next the antibody reacts with the antigen in the sample solution. The secondary antibody which is labeled with gold-nano-particle was applied. Then, the fixed GNP is pre-treated with relatively high potential (~1.2V) to be oxidized and be solved into the solution. Subsequently by reducing the potential, the gold is reduced and deposit onto the electrode. In this way, high signal to noise ratio is obtained. GLEIA can detect specific bio-substances as sensitive as ELISA in raw samples such as blood. However, GLEIA is still in their early stage of development and further improvement may be possible. In this paper we study the cyclic characteristic of oxidation and reduction, polymer cover-coating on working electrodes and glass covering for higher sensitivity of the detection. These methods result in higher signal intensities, so that more sensitive detection is expected in future.

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誘電泳動を用いた食品中残留農薬分析のための
免疫センサーの開発

兵庫県立大院物質理^a，JST-CREST^b

○Javier RAMON-AZCON ^a，安川智之^a,b，水谷文雄 ^a

NEGATIVE-DIELECTROPHORESIS TO DEVELOP AN IMMUNODEVICE FOR ANALYSIS
OF PESTICIDES RESIDUES IN FOOD

Javier RAMON-AZCON ^a, Tomoyuki YASUKAWA ^a,b, Fumio MIZUTANI <sup>a

a</sup> Graduate School of Material Science, University of Hyogo,
Kouto, Kamigori-Cho, Hyogo 678-1297
^b JST-CREST, 5, Sanbancho, Chiyoda, Tokyo 102-0075

We have applied particle manipulation based on negative-dielectrophoresis (n-DEP) to develop rapid and separation-free immunosensing systems. Two widely used pesticides, atrazine and bromopropylate, were used as target molecules A suspension of the fluorescence microparticles modified with a specific antibody was injected into the n-DEP device consisting of the interdigitated microarray (IDA) electrode and indium-tin-oxide (ITO) substrate immobilized by antigen. The application of AC voltage forced the particles to form a pattern on the ITO within 60 s. In the absence of analytes, patterned microparticles were irreversibly captured by the construction of immuno-complexes. When the microparticles bearing anti-atrazine IgG antibody were suspended in an analyte solution, irreversible capturing of microparticles was inhibited because of the occupation of the binding sites of the antibodies. We could discriminatively detect the fluorescence intensity of the captured microparticles from that of the uncaptured microparticles to eliminate the separation steps. A pre-incubation of microparticles in an orange juice containing analyte allowed for the determination of the atrazine and bromopropylate concentrations with a limit of detection of 4.0 and 1.5 µgL^-1, respectively. The assay was significantly accelerated and totally accomplished within 5 min. We simultaneously determined two pesticide residues by using the DEP devices with two channels.

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有限要素法を用いたイムノセンサのデジタルシミュレーションへのアプローチ

岩手大学大学院　工学研究科

○山口 昌樹、高橋 貴之、吉野 雄一朗、佐々木　誠

DIGITAL SIMULATION OF IMMUNOSENSOR FOR HORMONE MEASUREMENT
USING FINITE ELEMENT METHOD

Masaki YAMAGUCHI, Takayuki TAKAHASHI, Yuichiro YOSHINO, Makoto SASAKI

Graduate School of Engineering, University of Iwate,
Morioka, Iwate, Japan

An immunoassay is suitable for the molecular recognition of infinitesimal biochemical substance in biological sample. The authors have been developing an immunosensor that can analyse cortisol (CORT) from saliva as diagnostic marker of the stress diseases. In this study, the first step to construct of design of immunosensor was optimized for analysis time using finite element method (FEM). The labeled protein (conjugate) used for the molecular recognition was uniquely organic synthesis. The capillary action was simulated by kinetic analysis of molecular diffusion phenomenon using the Navier-Stokes equation when 40 μl of substrate solution at 2.8 mmol/l was dropped on to the sample pad. The concentrations of the substrate showed a maximum at 20 s when a diffusion coefficient of 0.75 m²/s was used. The immunosensor was fabricated based on the calculation result. The coefficient of determination between concentration of CORT and detected signal in a range of 1 – 10 ng/ml was R² = 0.90. It was indicated that the analysis of finite element method was useful for design of immunosensor.

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マイクロ流路RT-PCR－電気化学システムを用いた
インフルエンザウイルスの迅速検出

阪大院工^a、岡山理大^b

○山中 啓一郎^a、斎藤 真人^a、永谷 尚紀^b、民谷 栄一^a

CONTINUOUS-FLOW RT-PCR ON A MICROFLUIDIC DEVICE: RAPIDLY DETECTION
OF INFLUENZA VIRUS BASED ON ELECTROCHEMICAL DNA SENSOR

Keiichiro YAMANAKA ^a, Masato SAITO ^a, Naoki NAGATANI ^b and Eiichi TAMIYA ^a

^a Graduate School of Engineering, Osaka University,
Suita-shi, Osaka 565-0871
^b Faculty of Engineering, Okayama University of Science,
Okayama-shi, Okayama 700-0005

In this study, a rapid method for detection of influenza viral RNA using the microchannel chip and electrochemical sensor was demonstrated. The microchannel chip for continuous-flow reverse transcriptase polymerase chain reaction (RT-PCR) was fabricated using Polydimethylsiloxane (PDMS) based on standard photolithography techniques. The RT-PCR chip was constructed with four sections, RT reaction(50℃), PCR (2step PCR: 95 and 60-65℃) zone with channel size of 50x50μm and pressurizing channel zone for preventing air bubbles generating with size of 50x20 μm. For electrochemical detection of amplification, we selected Methylene blue (MB) as an indicator, because it is an electroactive intercalator and do not inhibit PCR amplification. The RT-PCR mixture containing MB run out at the outlet of chip device was collected, and electrochemical signals of amplicon were directly measured by square wave voltammetry (SWV) using disposable electrochemical printed (DEP) chips. As a result, the amplification could be detected from novel swine-origin influenza A (H1N1) virus RNA, and RT-PCR was completed within 15min at a total flow-through time from inlet to outlet. Those techniques, microfluidic device for fast RT-PCR and electrochemical measurement for rapid detection, are suitable to integrate, and it has potential to give the portable system for diagnostic tests.

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コンタクトフォトイメージングによる
オンチップ型サイトメーターの開発

東京農工大院生命

○田中 剛、須永 吉彦、松永 是

DEVELOPMENT OF ON-CHIP CYTOMETER
BASED ON CONTACT PHOTO-IMAGING

Tsuyoshi TANAKA, Yoshihiko SUNAGA, and Tadashi MATSUNAGA

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

A thin film transistor (TFT) photosensor was applied to high-content analysis of single cells by size-selective cell recognition, and identifying cell surface molecules based on chemiluminescence. Cell groups were directly placed on TFT photosensor surface, and imaged by contact photo-imaging. Micro-partitions were fabricated on the TFT photosensor surface by photolithography to assemble single cells on a single detection element. Individual cells were recognized as black-pixel patterns by white light irradiation. The black signal intensities were expected to be correlated with cell size. Furthermore, visualization of individual JM cells, stained with mouse anti-human CD8 IgG1 primary antibody and HRP-labeled anti-mouse IgG1 secondary antibody, as bright-pixels was successfully achieved using the micro-partitioned TFT photosensor integrated into a microfluidic chamber. The fabrication of micro-partitions on the surface of the TFT photosensor allows highly efficient single-cell entrapment and chemiluminescence-based detection of JM cells. This system will allow high-throughput image analysis of more than 104 cells with minimum optical system requirements.

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超高速フロースルー型PCRチップの開発

産総研^a、大阪大学^b

○渕脇　雄介^a、斉藤　真人^b、民谷　栄一^b、脇田　慎一^a、永井　秀典^a

DEVELOPMENT OF ULTRA RAPID FLOW-THROUGH PCR CHIP

Yusuke FUCHIWAKI ^a, Masato SAITO ^b, Eiichi TAMIYA ^b, Shin-ichi WAKIDA ^a, Hidenori NAGAI ^a

^a National Institute of Advanced Industrial Science and Technology (AIST),
1-8-31 Midorigaoka, Ikeda, Osaka 563-8577
^b Department of Applied Physics Graduate School of Engineering,
2-1 Yamadaoka, Suita, Osaka 565-0871

Flow-through polymerase chain reaction (PCR) is next generation chip device for integrating the PCR with a micro-total analysis system, which is quite different from conventional PCR. The DNA amplification on the device can be obtained by moving the sample solution through three temperature zones, heat denaturation, annealing and extension. In this study, novel segment-flow PCR technique was proposed and achieved ultra-rapid and high efficiency of DNA amplification. PCR microfluidics device was made of nonadhesive thinner seal and the cyclo-olefin polymer substrate (COP), which was processed a cutting work with micro-NC machine for the fabrication of micro flow channel. By using the heat to produce vapor pressure in microchannel as driving force of efficient flowing, successful DNA amplification more than 70% compared to desktop PCR cycler was obtained in shortest time 120s. The micro-fabricated PCR chip was found to detect in simple, ultrarapid and high amplification.

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乳牛の乳房炎早期診断のためのマイクロデバイス

筑波大院数理物質^a、クラレ くらしき研究センター^b

○岡田 浩平^a、福田 淳二^a、鈴木 博章^a、
綾野 賢^b、二階堂 祐子^b、西 泰治^b、岡 桂子^b

Microdevice for rapid diagnosis of bovine mastitis

Kouhei Okada ^a, Junji Fukuda ^a, and Hiroaki Suzuki ^a,
Satoru Ayano ^b, Yuko Nikaido ^b, Taiji Nishi ^b, and Keiko Oka ^b

^a Graduate School of Pure and Applied Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305-8573
^b Kurashiki Research Laboratories, Kuraray Co., LTD
Kurashiki, Okayama 710-8691

To identify dairy cows suffering from mastitis, we used the fact that the number of neutrophils increases in raw milk. The neutrophils, a type of white blood cells, produce superoxide (O₂^{• −}). Therefore, the amount of O₂^{• −} produced in raw milk can be used as an indicator for mastitis. To this end, we fabricated a microdevice consisting of thin-film three-electrode systems and polydimethylsiloxane compartments. A self-assembled monolayer (SAM) of cysteine was formed on a gold working electrode and superoxide dismutase (SOD) was immobilized there. When a raw milk sample obtained from a cow suffering from mastitis was injected into the device and opsonized zymosan, a strong neutrophil-activating agent, was added, a current increase distinctly different from the background was observed, demonstrating the applicability of this device for rapid diagnosis of mastitis.

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グリコーゲンホスホリラーゼb固定化物充填カラムを用いたエフェクターの
ホトメトリックバイオセンシング

神奈川工科大工

佐藤　生男、栁下　明子

PHOTOMETRIC BIOSENSING OF EFFECTORS USING A COLUMN PACKED
WITH GLYCOGEN PHOSPHORYLASE b IMMOBILIZED PREPARATIONS

Ikuo SATOH and Akiko YAGISHITA

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

A spectrophotometric flow-injection system armed with a column containing glycogen phosphorylase b immobilized porous glasses for biosensing of adenosine monophosphate(AMP) was constructed. Injections of substrate solutions containing glycogen and glucose 1-phosphate (G 1-P) mixed with AMP functioning as the effector into the system caused formation of orthophosphate, which was detected with use of a malachite green method. Increases in absorbance at 650 nm with increase in AMP with various concentrations were observed. Then, biosensing of AMP in micromolar levels could be achieved.

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濃度勾配マイクロデバイスを用いた
単一細胞毒性評価システムの構築

東京農工大^a、電中研^b

○モリ テツシ^a、林 拓磨^a、細川 正人^a、吉野 知子^a、
中園 聡^b、竹山 春子^a、松永 是^a

A SINGLE-CELL BASED MICROFLUIDIC GRADIENT DEVICE
FOR THE SCREENING AND EVALUATION OF CYTOTOXIC CHEMICALS

Tetsushi MORI ^a, Takuma HAYASHI ^a, Masahito HOSOKAWA ^a, Tomoko YOSHINO ^a,
Satoshi NAKASONO ^b, Haruko TAKEYAMA ^a, Tadashi MATSUNAGA ^a

^a Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 ^b Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Abiko, Chiba 270-1194

In cytotoxic chemical screening and evaluation, different cellular responses to chemicals due to different cellular conditions have been observed. Based on this understanding, we developed a single-cell based microfluidic gradient device applicable in cytotoxic chemical screening and evaluation by integrating a poly(dimethylsiloxane) (PDMS) structure, comprised of a chemical gradient chamber and microchannels, with a novel high efficient single-cell entrapment technology, referred to as microcavity array, priorly established in our laboratory. Upon successful fabrication of the device, optimization of the device, including chemical gradient generation and cell entrapment was performed. Chemical evaluation was subsequently conducted by inducing chemical responding HeLa cells entrapped within the device with various concentrations of chemical stimuli and bulk and single-cell analyses were performed accordingly. We believe that the features of the device fabricated in this work would enable the device to be used as an important tool in more detailed cytotoxic analytical researches.

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