Vol. 24, Supplement A (2008)

電気抵抗式ＷＯ₃薄膜センサの水素検知性能に及ぼす温湿度の影響

INFLUENCE OF TEMPERATURE AND HUMIDITY ON SENSING BEHAVIOR OF HYDROGEN GAS SENSOR USING PLATINUM-SUPPORTED WO₃ THIN FILM

Yuma SUZUKI^a、Shinji OKAZAKI^a、Hidemoto NAKAGAWA^b

^aGraduate School of Engineering, Yokohama National University Tokiwadai 79-5, Hodogayaku, Yokohama 240-8501, Japan
^bResearch Center for Advanced Science and Technology, The University of Tokyo
Komaba 4-6-1, Meguro-ku, Tokyo 153-8904, Japan

A chemoresistor-type hydrogen gas sensor using platinum-supported tungsten trioxide (Pt/WO₃) thin film was characterized. The film was deposited on quartz substrate by sol-gel method. This sensor utilizes change of impedance of Pt/WO₃ thin film. The electrical impedance at 1 kHz was measured with Au comb electrodes sputtered on the substrate. Under the dry condition, the impedance of the film sharply decreased with the exposure to hydrogen gas. This resulted from the formation of tungsten bronze whose electrical resistivity is lower than that of WO₃. When the atmosphere containing hydrogen gas was replaced with air, the impedance rapidly increased and reached to its initial level. However, the sensitivity under humid condition became lower in comparison with dry condition. In addition, temperature dependence on sensor response was characterized. Response speed and sensitivity of the sensor increased with increase of temperature. Furthermore, almost no influence of humidity was observed at high temperature (approximately 120℃). It is suggested that the humidity influence is caused by physisorbed water or condensed water which generate by the recovery reaction.

白金担持酸化タングステン薄膜を用いた高感度エタノールセンサ

Department of Applied Chemistry, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu-shi, Shiga 525-8577,
^*Advanced Technologies Fusion Laboratory, Matsushita Electric Works Ltd., Kadoma-shi, Osaka 571-8686

Pt doped WO₃ thin film sensors with Pt loadings of 0.2-5 wt% has been investigated on their ethanol gas sensing properties. Pt-H₂WO₄ suspension was prepared by mixing H₂WO₄ suspension and (NH₃)₂(NO₂)₂Pt. The suspension was dropped on the Au interdigitated micro electrode, dried, and calcined at 550 ℃ for 3 h. The sensor response was increased with increasing Pt loading. When the Pt loading exceeded 2 wt%, the sensor response to 1000 ppm ethanol was higher than 3000 (=Ra/Rg) at 200 ℃.The 2 wt% Pt-WO₃ sensor showed the linear correlation in log-log plot of sensor response vs. ethanol concentration. This sensor exhibited the excellent response-recovery characteristics as well as the good selectivity against CO and propane.

金担持酸化スズ薄膜マイクロセンサの硫化水素検知特性に及ぼすマイクロギャップ効果

EFFECT OF MICRO-GAP ELECTRODE ON HYDROGEN SULFIDE GAS SENSING PROPERTIES OF Au-DOPED TIN OXIDE THIN FILM MICROSENSORS

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

The micro-gap effect in Au-doped SnO₂ thin film micro sensors has been investigated on the dilute H₂S sensing. The mixture of Au sol and SnO₂ sol (0.5 wt% Au) was dropped on the micro-gap electrode fabricated by MEMS techniques (photolithography and FIB), dried and calcined at 600 ℃ for 3 h to be 0.5 wt% Au-SnO₂ thin film micro sensor. From the SEM image of Au-SnO₂ thin film, the tiny Au and SnO₂ particles (both ca. 20 nm in diameter) were observed in the film. The sensor response to dilute H₂S of Au-SnO₂ sensor was increased with increasing gap size. The result opposite to that in pure SnO₂ sensor was obtained. It is considered that the Au grain-SnO₂ grain interface has the different properties from the Au electrode-SnO₂ grain interface and that the number of Au grain-SnO₂ grain interface was increased with increasing gap size.

EFFECTS OF PHOSPHORIC ACID TREATMENT OF SnO₂ POWDERS ON THEIR GAS SENSING PROPERTIES

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

Effects of treatment of SnO₂ powders with a phosphoric acid (PA) solution on their gas sensing properties were investigated. Two types of SnO₂ powders, mesoporous (m-) SnO₂ and conventional (c-) SnO₂, were treated with and without PA solutions with different concentrations before calcination. The powders containing a small amount of phosphorus components (P/Sn = 1.33x10^-2～3.33x10^-2) with larger specific surface area showed larger response to 1000 ppm H₂ at 250℃. In addition, the PA-treated m-SnO₂ exhibited faster recovery behavior than PA-treated c-SnO₂. On the other hand, the powders containing a large amount of phosphorus components (P/Sn = 0.133～0.333) showed poor response as well as terribly slow response and recovery speeds.

MICROSTRUCTURE AND H₂ GAS SENSING PROPERTIES OF UNDOPED AND PD-DOPED SNO₂ NANOWIRES

Yanbai SHEN, Toshinari YAMAZAKI, Zhifu LIU, Dan MENG, Toshio KIKUTA, Noriyuki NAKATANI

Tin oxide (SnO₂) nanowires with a tetragonal structure were synthesized by thermal evaporation of tin grains at 900℃. The obtained nanowires were doped with palladium. The morphology, crystal structure, and H₂ gas sensing properties of undoped and Pd-doped SnO₂ nanowires were investigated. SnO₂ nanowires were approximately 30-200 nm in diameter and several tens of micrometers in length. Gas sensors based on undoped, 0.8 wt.% Pd-doped, and 2 wt.% Pd-doped SnO₂ nanowires were fabricated. These SnO₂ nanowire gas sensors showed a reversible response to H₂ gas at an operating temperature of RT-300℃. The sensor response increased with increasing Pd concentration. The sensor made of 2 wt.% Pd-doped SnO₂ nanowires showed a response as high as 253 for 1000 ppm H₂ gas at 100℃. The results demonstrate that Pd doping improves the sensor response and lowers the operating temperature at which the response is maximized.

マイクロメタンセンサにおける熱耐久性の改善

新コスモス電機　

○高田　義，堂上　長則

IMPROVEMENT IN HEAT SHOCK PESISTANCE OF MICROMACHINED GAS SENSOR BY EXAMINING ITS DESIGN

Tadashi Takada and Naganori Dougami

New Cosmos Electric Co., Ltd., 3-6-25 Mitsuya-naka, Yodogawa-ku, Osaka 532-0036, Japan

Heat shock resistance of a micro machined gas sensor that has a suspended type structure and a sintered SnO₂ thick film on the micro hot plate, was investigated for variously designed micro gas sensors. It was found that the sintered SnO₂-based thick film structure frequently brought about cracks near the boundary between the edges of the thick film and the suspended beam, although micro machined thick film type gas sensor was strongly dependent on the design of the micro hot plate.
The hook-shaped beam structure greatly improved the heat shock resistance.
The sensor endured repeated heat cycles between room temperature and 500℃, more than 8 million of heat cycles.

中性子回折法を用いた酸化スズ系材料の結晶構造解析

新コスモス電機^a、産総研^b

○前川　亨^a、皆越知世^a、中村俊一^a、野村勝裕^b、蔭山博之^b

Crystal Structure Analysis of The Catalysts Base on Tin Oxide using^a Neutron Diffraction Method

Toru MAEKAWA^a, Chise MINAGOSHI^a, Shun-ichi NAKAMURA^a,Katsuhiro NOMURA^b, Hiroyuki KAGEYAMA^b

^aNew Cosmos Electric Co., Ltd.
2-5-4 Yodogawa-ku, Osaka city, Osaka 532-0036
^b National Institute of Advanced Industrial Science and Technology (AIST)
1-8-31 Midorigaoka, Ikeda city, Osaka 563-8577

Ce-SnO₂ system shows stable catalysis over a long period of time at high temperatures, when the system is used as a catalyst layer for promoting gas selectivity in a semiconductor type gas sensors. This paper describes a crystal structure analysis of the Ce-SnO₂ system. The crystal structure of the system has been examined by a neutron diffraction method. The lattice constants and crystallite size were examined by an X-ray diffraction (XRD) method. The grain size and specific surface area were investigated by a small-angle X-ray scattering (SAXS) and a BET method, respectively.? Moreover, the effect of Ce doping on suppressing grain growth at high temperatures has been investigated.

○ 徐敏鉉^a、湯浅雅賀^a、木田徹也^a、許〓秀^b、島ノ江憲剛^a、山添　曻^a

MICRO STRUCTURAL CONTROL AND GAS SENSING CHRACTERISTICS OF TiO₂ BASED GAS SENSORS

Min-Hyun SEO^a, Masayoshi YUASA^b, Tetsuya KIDA^b, Jeung-Soo HUH^c, Kengo SHIMANOE^b, Noboru YAMAZOE^b

^aDepartment of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
6-1 Kasuga Koen, Kasugashi, Fukuoka 816-8580, Japan
^bDepartment of Energy and Material Sciences, Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga Koen, kasuga-shi, Fukuoka 816-8580 Japan
^cDepartment of Materials Science and Matallurgy, Kyungpook National University, Sangyuk-Dong 1370, Bukgu, Daegu, Republic of Korea

Preparation and morphology control of TiO₂ nanoparticulate films for gas sensor applications are investigated. To examine the effect of morphology of the sensing films on the sensing characteristics, TiO₂ with different morphologies, nanoparticles and nanotubes, were used for the film preparation. TiO₂ nanotubes were prepared by a hydrothermal treatment of TiO₂ nanoparticles in a NaOH solution at 160, 200 and 230 ℃ for 24 h and subsequent washing with an HCl solution. TiO₂ nanotubes of 1?m in length and 50 nm in diameter were formed at 200 and 230 ℃. With increasing the temperature of hydrothermal treatment, the length of tubes increased and the distribution of diameter became narrower. However, the treatment at lower temperature produced aggregated TiO₂ nanoparticles. The sensing films composed of nanotubes prepared at higher temperature showed a better sensitivity to toluene at 450 ℃ than those composed of aggregated TiO₂. SEM images indicated that the sensing films composed of nanotubes has a more porous morphology, suggesting the importance of microstructure control of sensing layers for improving the sensitivity to large size molecules such as toluene.

RECENT DEVELOPMENT STATE AND INNOVATION OF SEMICONDUCTOR GAS SENSORS

Noriyuki OGASAWARA

　Nearly 50 years have passed since the semiconductor gas sensor was born first in the world. After Seiyama and Taguchi first applied the patent in 1961, some time of dawn period passed, then the sensor was put to practical use early in the 1970s, when the history of home gas leak detectors began. Since then the semiconductor gas sensors have been able to detect various gases thanks to the wisdom and exertion of sensor engineers in the world. Also newly designed application products have been realized with the progress of sensor applied technology such as an advanced electronic circuits and software. This paper will introduce several innovation examples using semiconductor gas sensors and I wish this will be of some suggestions to the further development of gas detection and its commercialization.

含浸金ナノ粒子を検知極に用いたジルコニア炭化水素センサ

九大産学連携センター

○ブラディミルプラシニツァ、ペルマルエルマレイ、三浦則雄

YSZ-BASED HYDROCARBON SENSOR USING IMPREGNATED Au NANO-PARTICLES AS SENSING ELECTRODE

○Vladimir V. PLASHNITSA, Perumal ELUMALAI, Norio MIURA

Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka 816-8580

The nano-structured Au layers were fabricated on a yttria-stabilized zirconia (YSZ) plate by using each of the colloidal gold solutions having the particles size of 5-80nm.
After annealing at 1,000℃ for 2 h, gold particles were found to be impregnated into the surface YSZ layer, forming the low-conductive gold nano-network which worked as a sensing electrode (SE). The obtained sensors were evaluated at temperatures of 550-800℃ under the wet condition (5 vol.% H₂O) aiming at the selective detection of hydrocarbons (HCs). As a result, the sensors fabricated by using the gold colloids of 5 nm and 30 nm-size showed the selective response to C₃H₆ at 500℃. Such a behavior seems to be ascribed to the higher oxygen coverage of nano-gold favored to the formation of intermediate compound.

南　卓也・湯浅雅賀・○木田徹也・上村裕一^*・島ノ江憲剛・山添　曻

INVESTIGATION OF THE ELECTRODE STRUCTURE ON BICUBOx SOLID ELECTROLYTE FOR DETECTION OF ORGANIC GAS

Takuya MINAMI^a, Masayoshi YUASA^b, Tetsuya KIDA^b, Yuichi KAMIMURA^c, Kengo SHIMANOE^b, Noboru YAMAZOE^b

^aDepartment of Molecular and material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
^bDepartment of Material Sciences, Faculty of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580
^ccDepartment of Anesthesiology & Critical care Medicine, kagoshima University School of Medicine, Kagoshima-shi, Kagoshima 890-8520

A planar-type gas sensor based on BiCuVOx (Bi₂Cu_0.1V_0.9O_5.35) solid electrolyte was fabricated for detection of volatile oganic compounds (VOCs).
Electromotive force (EMF) of the sensor device, in which a BiCuVOx sintered disk was fitted with two composite electrodes of BiCuVOx/La_0.6Sr_0.4Co_0.8Fe_0.2O₃ with different thicknesses, was measured in the presence of 2～40 ppm ethanol at 380～450℃. The thinner and thicker electrodes were used as sensing and counter electrodes, respectively. To separately measure the sensitivity of the electrodes with different thicknesses, another electrode was fitted as a reference electrode based on dry air. At higher temperature (450℃), the sensing electrode showed a higher sensitivity to ethanol than the counter electrode. Consequently, it was possible to detect ethanol by measuring the sensing electrode potential relative to the counter electrode for the planar device. However, at lower temperature (380℃), the sensing electrode showd a sensitivity independent on ethanol concentration in a higher consentration range, making difficult to detect ethanol. This study strongly demonstrates the impotance of the design of the electrode structure for detection of VOCs.

トータル炭化水素濃度の検出を目指した混成電位型ジルコニアセンサ

九大院総理工^a、日本学術振興会^b、九大産学連携センター^c

○藤尾侑輝^a、上田太郎^a、和間良太郎^a、エルマレイペルマル^b,c、三浦則雄^c

MIXED-POTENTIAL-TYPE ZIRCONIA-BASED SENSOR AIMING AT MEASUREMENT OF TOTAL CONCENTRATION OF HYDROCARBONS

○Yuki FUJIO^a、Taro UEDA^a、Ryotaro WAMA^a、Perumal ELUMALAI^b,c、Norio MIURA^c

^a Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
^b Japan Society for the Promotion of Science, Tokyo 102-8471
^c Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580

The sensing characteristics to various gases were examined for the sensor using a yttria-stabilized zirconia (YSZ) tube and oxide sensing-electrode (SE). Among five kinds of Zn-based oxides examined, ZnCr₂O₄-SE was found to give the most selective response as well as good sensitivity and response rate against C₃H₆. The sensitivity and the 90% response time to 100 ppm C₃H₆ were ca. 50 mV and ca. 10 s, respectively, at 550℃. The sensitivity (Δemf) of the present sensor varied almost logarithmically with the C₃H₆ concentration in the range of 10 - 400 ppm even in the presence of 5 vol.% H₂O. The sensitivities to various kinds of hydrocarbons were also examined at 550℃ for the present sensor. As a result, a linear correlation was observed between the sensitivity and the carbon number of hydrocarbons examined

○中里嘉浩, 前川亨, 鈴木健吾

DEVELOPMENT OF A MICRO-OXYGEN SENSOR USING AN OXYGEN PUMP

A micro-oxygen sensor has been developed using yttria stabilized zirconia (YSZ). The sensor consists of a YSZ element with a pair of Au electrodes where an oxygen pump is induced by applying electric potential to the electrodes and an alumina substrate with a Pt thin film heater for heating the YSZ element. The sensor showed high sensitivity to oxygen gas in a concentration range of 210ppm to 21% at the working temperature of 600℃. 90% full response time of the sensor was less than 10 seconds. Moreover, the sensor had excellent oxygen selectivity, showing almost no sensitivity to the other gases teste

安定化ジルコニアと酸化物系検知極を用いた混成電位型アンモニアセンサ

九大産学連携センター^a、日本学術振興会^b、九大院総理^c

○ペルマルエルマレイ^{a, b}、ブラディミルプラシニツァ^a、藤尾侑輝^c、三浦則雄^a

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

○Perumal ELUMALAI^{a, b}, Vladimir V. PLASHNITSA^a, Yuki FUJIOc, Norio MIURA^a

^a Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka 816-8580
^b Japan Society for the Promotion of Science, Tokyo 102-8471
^c Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-shi, Fukuoka 816-8580

A planar sensor using yttria-stabilized zirconia (YSZ) and oxide-based sensing electrodes (SE) was fabricated and examined for detection of NH₃ at high temperature. Among the various oxide-based SEs tested, the sensor attached with NiO/Au-SE was found to exhibit good sensitivity and selectivity to NH₃ at 800℃ under wet condition. While the cross sensitivities to the various other gases examined were negligible, the sensitivity to 100 ppm NH₃ was about -34 mV. The Demf of the sensor varied almost linearly with the NH₃ concentration in the examined range of 20-100 ppm. The 90% response time of the sensor was about 50 s. In addition, the NH₃ sensitivity was found to be hardly affected by the change in the concentration of water vapor in the examined range of 2 - 13 vol.%.

Pd-Pt合金電極を取り付けた陽極酸化TiO₂膜の水素センサ検知特性

HYDROGEN SENSING PROPERTIES USING ANODIZED TiO₂ FILMS AND Pd-Pt ALLOY ELECTRODES
　　　　　　　
Masaki NAKAOKA, Takeo HYODO, Yasuhiro SHIMIZU and Makoto EGASHIRA

Faculty of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521

H₂ sensing properties of diode-type sensors using anodized TiO₂ films and Pd-Pt alloy electrodes have been investigated. The sensor subjected to normal pretreatment in air showed larger H₂ response in wet air than in dry air, while it exhibited much slower response speed in wet air. On the other hand, the sensor pretreated additionally in N₂ atmosphere showed slightly larger H₂ response in dry N₂ than that in wet N₂. As a result, H₂ response of the air-treated sensor in wet air was quite comparable with that of the N₂-treated sensor in wet N₂. Thus, it was revealed that the existence of water vapor reduced the influence of pretreatment and measurement atmospheres on H₂ sensing properties of the diode-type sensors.

反応場を極小化した接触燃焼式水素センサの応答特性

新コスモス電機

○宮崎　洋、鈴木　健吾

THE RESPONSE OF CATALYTIC COMBUSTION TYPE HYDROGEN GAS SENSOR　MINIATURIZED REACTION FIELD

A catalytic combustion type hydrogen sensor (micro-sensor) has been developed using a micro platinum wire coil embedded within a bead catalytic material. The sensor showed very fast response to hydrogen gas and the time to reach thermal equilibrium became shorter when the sensor is powered on, as compared with the conventional catalytic combustion type sensor. Moreover, the sensor showed excellent long-term stability even though its bead size was miniaturized to the size of 0.2mm in spherical diameter.

ロール型検知紙を用いたオゾン濃度測定装置の開発及び特性評価

○丸尾容子，山田巧、根本康恵、國岡達也、三輪貴志、中村二朗

DEVELOPMENT OF OZONE MONITORING DEVICE USING DEVELOPED PAPER ROLL FOR OZONE DETECTION

Yasuko Y. MARUO, Takumi YAMADA, Yasue NEMOTO, Tatsuya KUNIOKA,Takashi
MIWA, and Jiro NAKAMURA

We have developed a cassette-type container housing a roll of paper for ozone detection and a device consisting a reflection measurement unit and a winder unit for the paper roll. The paper is highly sensitive to ozone. We achieved long-term indoor ozone monitoring with sufficient sensitivity (better than 10 ppb) using the developed system. The correlation coefficient (R) between the ozone concentration measured with our developed system and that measured with a commercial ozone analyzer was 0.79 showing that the values were in good agreement.

There is a growing market demand of a sensor which can precisely measure breath alcohol concentration. We have begun to develop an amperometric
electrochemical gas sensor with working electrode (W.E.) and counter electrode (C.E.) containing Pt as a　catalyst. As a result, it was found that alcohol
selecting can be controlled by changing Pt weight ratio of the W.E. and the C.E..

金ナノ粒子修飾カーボン繊維電極を用いたびらん性有毒化学剤の電気化学検出法の開発

○谷口功^a、山田洋行^a、西山勝彦^a、松浦宏昭^b、中野信夫^b、瀬戸康雄^c

Development of Electrochemical Sensor for Blister Agents Using Carbon Fiber Electrode Modified with Au Nano Particles

Isao TANIGUCHI^a, Hiroyuki YAMADA^a, Katsuhiko NISHIYAMA^a, Hiroaki MATSUURA^b Yasuo NAKANO^b, Yasuo SETO^c

^a Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555
^b Riken Keiki Co., Ltd., 2-7-6, Azukizawa, Itabashi-ku 174-8744
^c National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa 277-0882

By choosing carbon material, the selectivity and sensitivity of gases are able to control using its surface properties. Here, we report that a compact type of electrochemical sensor to detect blister agents such as mustard gas (HD) or lewisite 1 (L1) using the carbon electrode modified with gold nano particles, since the effective detection method for the blister agents gas not been developed. The commercially available carbon film electrodes modified with gold to detect phosphine or azurin had no response for HD. However, carbon fiber electrodes modified with Au nano particles showed reratively high sensitivity for HD and the sensitivity of the sensor depended on the type of carbon materials, the amount of modified gold, and the applied electrode potential. On the carbon fiber electrode (ca.6.2 cm²) modified with gold nano particles in an H₂SO₄ solution, ca 1 μA of oxidation current was observed for 9.6 mg m^-3 of HD gas with the flow rate of 300 ml min^-1 No response current was observed at carbon fiber electrodes with no modification of gold. The excellent linear relationship of the current vs.〔HD〕was obtained with the range between 1 and 9.6 mg m^-3 of HD. By using the sensor prepared in this study, we can detect 1.5 mg m^-3 , which is required concentration for HD gas detection.

Design of Hydrogen-Phosphate-Ion Sensor Based on Metal-Alloy Thin-Film Electrode

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

A practicable hydrogen-phosphate ion sensor which can be used on site monitoring has proposed and examined. The cobalt based alloy thin-film electrode prepare by an electrodepositing showed hydrogen-phosphate ion selective potential response between 1.0x10^-4 and 1.0x10^-2M in acidic medium (pH 5.0). The potentiometric response characteristics were changed depending on the alloy composition. The Co-Mn alloy electrode showed fast response, while the Co-Fe alloy electrode showed good reproducible response. In this work, the potentiometric hydrogen-phosphate ion response characteristics and mechanism of the Co-Me (Me = Fe, Mn, Ni, Cr etc.) thin-film electrodes were investgated by using XPS, FT-IR, etc.

Liquid Electrode Plasma (LEP) を用いたジルコニア（ZrO₂）中の微量元素の測定-２

北陸先端技術大学院大学¹大阪大学院²　㈱マイクロエミッション³

○伴野倫子¹　宮城邦夫¹　北野厚志¹　山本保³ 民谷栄一^1,2　高村弾^1,3

Measurement of trace elements in zirconium dioxide(ZrO₂) by Liquid Electrode Plasma(LEP)

Machiko BANNO¹, Kunio MIYASHIRO¹, Atsushi KITANO¹
Tamotsu YAMAMOTO³, Eiichi TAMIYA^1,2 and Yazuru TAKAMURA^1.3

¹ School of Material Science, Japan Advanced Institute of Science And Technology,
1-1, Asahidai, Nomi, Ishikawa, Japan
² Department of Applied Physics, Osaka University
2-1, Yamadaoka, Suita, Osaka, Japan
³ 2-13, Asahidai, Nomi, Ishikawa, Japan

Inductively Coupled Plasma Optional Emission Spectrometry (ICP-OES) has been employed for the detection of the trace element in zirconium dioxide conventionally.
However, zirconium is a line-rich element, so that it is difficult to measure the trace element in zirconium dioxide by ICP-OES. On the other hand, Liquid Electrode Plasma Optical Emission Spectrometry (LEP-OES) developed by us has many advantages; such as on-site monitoring, small apparatus, low cost. In addition that the sensitivity of the zirconium by LEP-OES is extremely low. So we can expect very easy measurement of other trace elements in zirconium dioxide by LEP-OES. In this paper, the sensitivity of Na, Li measurement in zirconium dioxide is studied. Each detection limit of Na, Li in 4000 ppm zirconium dioxide was about 0.1 ppm, 0.3 ppm in measurement using LEP-OES.

分子認識用人工レセプターを用いた水道水中シマジン計測のための測定システム

SENSING SYSTEM FOR DETERMINATION OF SIMAZINE IN TAP WATER UTILIZING MORECULARLY IMPRINTED ARTIFICIAL RECEPTOR FOR SIMAZINE

Department of Bioinformatics, Faculty of Engineering, Soka University1-236 Tangi, Hachioji, Tokyo 192-8577

The previously-reported simazine sensing system, which was composed of molecularly imprinted artificial polymer receptor (Sim-MIP) column and electrochemical measurement, was improved to detect low concentration of simazine in tap-water within one hour. In the improved system, 100 ml of simazine solution containing 10-20 nM (2-4 ppb) into the small column packed with 3 mg of Sim-MIP and the bound simazine was loaded from the column with 100 μl methanol to concentrate in the eluent. It was examined with 900 μl of electrolyte (0.1 M KCl) and detected electrochemically. Ten nM (2 ppb) simazine of the environmental limit could be detected in an hour. Cathodic peak current of simazine was detected, and the electrochemical detection limit was 1 μM, which was concentrated from 10 nM (2 ppb), 100 ml of simazine with this system.

分子鋳型を持つ過酸化ポリピロールを用いたATP定量法の開発

ATP SENSING BY USING MOLECULARLY IMPRINTED OVEROXIDIZED POLYPYRROLE FOR HACCP APPLICATION

Shintaro TAKEDA^a, Satoru MIZUGUCHI^b, Hitoshi FUNAHASHI^b, Hiroshi SHIIGI^a, Tsutomu NAGAOKA^a

^aFrontier Science Innovation Center, Osaka Prefecture University, 1-2 Gakuencho, Sakai 599-8570
^bAtect corporation, 2-1-36 Sumida, Higashi-osaka 578-0912

An electrochemical preparation technique for a molecularly imprinted overoxidized polypyrrole (OPPy) film and its recognition property for Adenosine 5'-triphosphate (ATP) are investigated for application to ATP sensing and clarification of the principle of molecular recognition. The molecularly imprinted OPPy has been derived from ATP doped polypyrrole (PPy) film grown on a glassy carbon electrode (GCE) with a potentiodynamical overoxidation process in an alkaline solution. The molecularly imprinted OPPy modified electrode showed excellent sensitivity, reproducibility and stability for determination of ATP in a wide range from 10–10 to 10–2 M at trace level concentrations (detection limit: 500pM).

分子インプリント薄膜のゲート効果と鋳型物質/機能性モノマー間の結合力の関係

芝浦工大

○関根真一，旗持明利，砂山昌史，吉見靖男^*

INFLUENCE OF AFFINITY BETWEEN TEMPLATE AND FUNCTIONAL MONOMER ON GATE EFFECT OF MOLECULARLY IMPRINTED POLYMER

Shinichi SEKINE, Akitoshi HATAMOCHI, Masashi SUNAYAMA, Yasuo YOSHIMI^*

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

A thin layer of molecularly imprinted polymer (MIP) changes their solute diffusive permeability by specific binding with its templates. The phenomenon is termed as gate effect. In this study, we discussed influence of the affinity between the template and the functional monomer on the gate effect. The degree of gate effect was determined by cyclic voltammetry of ferrocene in dichloromethane with the electrode on which MIP of phenylalanine anilide (PAA) was grafted. Methacrylic acid, 2-(trifluoromethyl) acrylic acid, itaconic acid, or 2-acrylamide-2-methylpropane sulfonic acid was used as a functional monomer. The affinity between the template and the functional monomer was evaluated by 1H-NMR spectroscopy. As the results, the gate effect was observed only by the MIP electrode using itaconic acid. The 1H-NMR spectrum showed that the itaconic acid binds with PAA most strongly in polar solvent. These results indicate that the affinity between the template and the functional mon omer during the MIP synthesis plays important role for the gate effect.

Lab-on-a-Chip INTEGRATED WITH ChemFET DETECTOR (3):
MICRO-FIA CHIP FOR CATIONIC SURAFCTANT ASSAY IN DENTAL RINSES

^aHuman Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST),
Midorigaoka 1-8-31, Ikeda, Osaka 563-8577, Japan
^bFaculty of Engineering, Shibaura Institute of Technology,
Toyosu, Koto-ku, Tokyo 135?8548, Japan

A cationic surfactant ion-selective field-effect transistor (cationic surfactant-ISFET) has been fabricated with ion-pair of cationic surfactant and tetrakis[3,5-bis(trifluoromethyl) phenyl]borate as an ion-sensing material. The cationic surfactant-ISFET shows an almost Nernstian response (58.5 mV/decade) to tetradecyldimethylbenzylammonium chloride (Zephiramine) in 1.0 × 10^-6 M and 1.0 × 10^-3 M. The cationic surfactant-ISFET can be used over a range of pH values, between pH 3 and 9. The cationic surfactant-ISFET shows excellent selectivity for Zephiramine over small inorganic cations, but shows similar selectivity for other cationic surfactants, such as hexadecyltrimethylammonium and stearyl- trimethylammonium ions. A microfluidic polymer chip was integrated with the cationic surfactant-ISFET, and was fabricated using polystyrene plates and stainless wires as a template for the channel. Cationic surfactant-ISFETs used in a batch system and microchips integrated with cationic surfactant-ISFETs showed very similar performance in terms of low detection limits, slope sensitivity and the stability of the potential response. The microfluidic polymer chip was investigated to possibility to the determination of cationic surfactants in dental rinses.

○右田聖¹，尾笹一成²，田中智也¹，池野慎也¹，春山哲也¹

Artificial enzyme based ISFET for one-stop sensing of various phosphoric anhydrides

S. MIGITA¹, K. OZASA², T. TANAKA¹, S. IKENO¹, and T. HARUYAMA¹
¹Department of Biological functions and Engineering,
Kyushu Institute of Technology,
Kitakyushu Science and Research Park, Fukuoka, 808-0196, Japan

²RIKEN (The Institute of Physical and Chemical Research)
2-1 Hirosawa, Wako, Saitama 351-0198

We have developed novel type of biosensor using an artificial enzyme membrane for the molecular commonality sensing. The artificial enzyme that recognizes and hydrolyzes phosphoric anhydride bond structures selectively. It was designed and synthesized by means of our original procedure, and covered on a T₂O₅-gate ion-sensitive field-effect transistor (ISFET). H₂PO₄^- ion is produced through the catalytic reaction in the artificial enzyme membrane, and is accumulate in the membrane on the ISFET. The accumulated H₂PO₄- ion causes a shift in the static ISFET output as the sensor response. A key advantage of the artificial enzyme is its specific structure selectivity for the phosphoric anhydride bonds, which is one of the dominant and characteristic structures in biological energy substances. The molecular commonality detection of the phosphoric anhydride bonds is a novel tactic for biosurveillance.

カーボンナノチューブとプラズマ重合膜を
用いる化学／バイオセンサ～カーボンナノチューブ濃度の最適化

CHEMICAL/BIO SENSOR WITH CARBON NANOTUBE AND PLASMA-POLYMAERIZED FILM - OPTIMIZATION OF LOADING CONCENTRATION OF CARBON NANOTUBE

Yasunori MATSUI, Tatsuya HOSHINO, Masahiro YOSHIZAWA, and Hitoshi MUGURUMA

Department of Electronic Engineering, Shibaura Institute of Technology, Toyosu, Koto-ku, Tokyo 135-8548

We report on an electrochemical (chemical and biochemical) sensor that is based on carbon nanotubes (CNT) and plasma-polymerized film (PPF). The CNTs were sandwiched with 2 nm-thick acetonitrile PPFs. Under PPF layer was deposited onto sputtered gold electrode. We optimized the CNT concentration for casting formation onto the under PPF layer. The nicotin adenine dinucleotide (NADH) sensor showed highsensitivity (a sensitivity of 240 mA mM^-1 cm^-2, a correlation coefficient of 0.993, a linear response range of 0.009-2.3 mM, a detection limit of 3.9 mM at S/N=3, +0.4 V vs Ag/AgCl), and rapid response (< 7s in reaching 95% of maximum response). The glucose biosensor also showed ultrasensitivity (a sensitivity of 40 mA mM^-1 cm^-2, a correlation coefficient of 0.992, a linear response range of 0.025-1.9 mM, a detection limit of 6.2 mM at S/N=3, +0.8 V vs Ag/AgCl), and rapid response (< 4s in reaching 95% of maximum response). This high performance is attributed that CNTs offer excellent electrocatalytic activity and enhance electron transfer, and that PPF and/or plasma process for CNTs are the electrochemistry-friendly platform.

（創価大工）

横田宣之、阿弓佳央梨、中根優子、渕脇雄介、○久保いづみ

Study on the Preparation Method of Molecularly Imprinted Polymer Thin Layer Modified Sensor for the Determination of Bisphenol A

Nobuyuki YOKOTA, Kaori AYUMI, Yuko NAKANE, Yusuke FUCHIWAKI and Izumi KUBO

Department of Bioinformatics, Faculty of engineering, Soka University
Hachioji-shi, Tokyo, 192-8677

　 Preparation of molecularly imprinted polymer (MIP) thin layer on a sputtered gold electrode was investigated in order to establish a bisphenol a sensing system. MIP for bisphenol A was polymerized MIP cocktail composed of 4-vinylpyridine, EDMA and bisphenol A. It was spin-coated on the surface of the gold electrode and polymerized by UV light irradiation for 2 - 5 min. The surface of bare gold electrode and polymerized MIP was observed with Atomic Force Microscopy (AFM). The gold particle, which was observed on the bare gold electrode, not observed with the MIP modified surface. The angle of inclination of MIP modified electrode became smaller than that of bare gold electrode. With the gold electrode anodic peak was observed below the concentration of 0.05mM of bisphenol A.

藻類細胞バイオセンサのスクリーン印刷による作製と FIAによる評価

Toxicity test of amperometric screen-printing algal biosensor with Flow Injection Analysis

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

A screen-printing algal biosensor was fabricated for water toxicity test. Algal ink was prepared by mixing the algal cells, multiwall carbon nanotube and 4 wt% sodium alginate solution. The algal ink was printed on the carbon electrode surface by screen printing. The electrode printed was immersed in 0.2 mM CaCl₂ solution for gelation. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. The oxygen reduction current increased when the algal biosensor was illuminated. These results indicated that the printed algae retained photosynthetic activity. Responses of the algal biosensor to a toxic compound, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine), were evaluated as inhibition ratios of the reduction current.

複合酸化物を用いた高選択性環境計測用ガスセンサの開発

Tatsumi ISHIHARA

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

Development of reliable gas sensor is strongly requested from environmental monitoring. In this study, amperometric sensor for monitoring hydrocarbon
and NO is investigated by using oxygen pumping current through LaGaO₃ electrolyte. It was found that the combination of active and inactive
electrode for hydrocarbon or NO oxidation is effective for high selectivity. In case of hydrocarbon sensor, the element of Pt-Co-LDC/LSGF
(7373)/La_0.5Sr_0.5MnO₃ shows the highest sensitivity and for NO sensor, La_0.5Sr_0.5MnO₃/La_0.8Sr_0.2Ga_0.8Mg0.1Ni_0.1O₃/La_0.4Sr_0.6Mn_0.8Ni_0.2O₃ is the
optimized one. This sensor exhibits the current change against only NO and so it is expected that the detection of NO separated to NO₂ becomes
realized.

機能性担体を用いた高性能バイオセンサの開発

産業技術総合研究所

矢吹　聡一

DEVELOPMENT OF HIGH-PERFORMANCE BIOSENSORS BASED ON FUNCTIONAL MATRICES

Soichi YABUKI

National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8566

High-performance biosensors based on several matrices were developed. In this presentation, I show here some biosensors based on four different kinds of matrices as follows; 1) biosensors based on polypyrrole matrix for the enhancement of electron transfer between enzyme and electrode, 2) biosensors based on carbon paste matrix and chemical modified-enzyme to construct high-sensitive biosensors, 3) biosensors based on colloidal gold matrix which shows electroconductivity, and 4) biosensors based on polyion complex membrane matrix for the high density immobilization to enzymes. The high-performance biosensors based on these matrices can be obtained easily, so that these systems would be utilized to construct practical biosensors.

消化管内マイクロカプセル型診断デバイスのための高機能集積化生化学分析デバイスの構築

Graduate School of Pure and Applied Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305-8573

An integrated bio / chemical analysis device for the determination of the activity of proteases was fabricated. The device consisted of a pH-responsive valve, a micro chamber filled with a freeze-dried enzyme substrate, and an automatic micro-pH-stat. The valve was operated based on electrowetting using a nonstandard three-electrode system. The sample solution was automatically injected into the chamber and rapidly mixed with the freeze-dried substrate. The automatic micro-pH-stat was also based on a nonstandard three-electrode system. The activity of proteases was measured at the optimum pH of each enzyme. A current accompanying an enzymatic reaction in the micro-pH-stat showed a clear dependence on the activity of proteases.

Zhenyu Lin^{a, b}, Yasufumi Takahashi^a, Yuusuke Kitagawa^a, Taizo Umemuraa, Hitoshi Shiku^a, Tomokazu Matsue^a*

^aGraduate School of Environmental Studies, Tohoku University,
6-6-11 Aoba, Aramaki, Sendai 980-8579, Japan
^b Ministry of Education Key Laboratory of Analysis and Detection Technology for
Food Safety (Fuzhou University), and Departmentof Chemistry, Fuzhou University,
Fuzhou, Fujian, 350002, China

Column and row electrodes are orthogonally arranged on the chip to establish an addressable microelectrode array for electrochemical detection. The established system is scalable, enable to detect amperometric signal at the individual crossing point of column and row electrodes. This device had been applied to study the redox recycling of 4mM K₃[Fe(CN) ₆] for different parameters including electrode width, gap between the electrode array. The effect of waiting time on the read out current was also evaluated. A 10×10 array data was obtained within 22 second for visualize of character “E”. It shows this system has a lot of potential application, such as two-dimensional imaging of some species’ distributions in the flowing system and characterization of bio-functional microparticles in the solution.

○伊藤　健^a、廣井哲也^a、荒木真由美^a 大澤利幸^a、山村　晃^b、松本邦男^b

Takeshi ITO ^a, Tetsuya HIROI ^a, Mayumi ARAKI ^a, Toshiyuki OHSAWA ^a,
Akira YAMAMURA ^b, Kunio MATSUMOTO ^b

^a Kanagawa Industrial Technology Center, Ebina-shi, Kanagawa 243-0435
^b Kanagawa Institute of Technology, Atsugi-shi, Kanagawa 243-0292

We developed a microfluidic device which was integrated with a microreactor and an electrochemical detector for detecting histamine. Histamie oxidase (HOD, from KAIT-B-007) was produced using a recombinant DNA technique, and was immobilized with chitosan beads. The beads were introduced into a microchannel to form the microreactor. Hydrogen peroxide produced from an emzyme reaction was detected using the electrochemical detector. For decreasing the sample volume and detection time, flow injection analysis (FIA) was adopted. Volumes of the microreactor and a sample loop for the injection were 480 nL and 320 nL, respectively. The peak of the oxidation current was observed at 35 s after the injection with the flow rate of 5μL/min. The peak area, is equal to the electric charge, showed a linear response in range from 10μmol/L to 5 mmol/L histamine at the flow rate of 5μL/min. These results show that our microfluidic biosensing system has the potential to assist minuaturization with small sample volume and short determination time for food analysis.

フローセル対応型水晶振動子バイオセンサを用いた抗原抗体反応の計測

○樋口　誠，橋本昌彦，加藤　寛，梶　弘和，西澤松彦，安部　隆

MEASUREMENT OF ANTIGEN-ANTIBODY REACTION BY A QCM BASED BIOSENSOR SUITABLE FOR MOUNTING ON A FLOW CELL

Makoto HIGUCHI，Masahiko HASHIMOTO，Hiroshi KATO， Hirokazu KAJI，Matsuhiko NISHIZAWA，Takashi ABE

Department of Bioengineering and Robotics，Graduate School of Engineering，Tohoku University，Sendai，980-8579，Japan

A new type of quartz crystal microbalance （QCM） which has exciting electrodes on one side of the AT-cut quartz crystal and a conducting layer （gold）
on the other side has been developed for biosensing. This QCM sensor, antiparallel coupled resonator （ACR）, has some advantage in that it is suitable
for mounting on a flow cell, sensing in liquid with array fabrication and spin coating because the exciting electrodes are not located on the sensing
side. We evaluated performance of the ACR by measuring antigen-antibody reaction with the ACR-integrated flow cell.

テーパー状マイクロ流路を用いた１細胞からの核酸解析

北陸先端大院大^a、阪大^b

○野間慶一^a、松浦宏紀a、富澤祐一^a、山村昌平^a、民谷栄一^b、高村禅^a

USING A TAPER SHAPED MICRO CHANNEL

Keiichi NOMA ^a, Hiroki MATSUURA ^a, Yuuichi TOMIZAWA ^a, Shohei YAMAMURA ^a, Eiichi TAMIYA ^b and Yuzuru TAKAMURA ^a

^a Material of Science, Japan Advanced Institute of Science and Technology (JAIST),
1-1, Asahidai Nomi, Isikawa, JAPAN
^b Department of applied Physics, Osaka University,
2-1, Yamadaoka, Suita, Osaka, JAPAN

An integrated microfluidic chip was developed to analyze DNA/RNA from of a DNA/RNA extraction part and PCR (Polymerase Chain Reaction) reaction part. In order to extract DNA/RNA from cell lysate, a taper shaped channel was installed. Nucleic acid solution was introduced into a taper shaped channel by pressure flow and simultaneously electric field of a direct current was applied to the channel in the counter direction of a flow. Then, the nucleated acid was selectively trapped at the taper shape channel and was extracted from the lysate. Next, the flow was switched by integrated micro valves to push out the extracted DNA/RNA to the PCR chamber with PCR reagent. The entire chip was set on to a conventional thermal cycler and the PCR was performed. The evaporation of PCR reagent during the heat cycles was suppressed by mineral oil. The PCR condition was optimized for the PDMS made chamber. The full sequence of operation from DNA trap extraction to PCR detection was successfully demonstrated on the single chip.

○橋本昌彦、川島丈明、関根宗一郎、梶弘和、安部隆、西澤松彦

ARRANGEMENT OF MULTIPLE CELL TYPES WITHIN MICROCHANNEL BY COMBINATION OF ELECTROCHEMICAL BIO-LITHOGRAPHY AND DIELECTROPHORESIS

Masahiko HASHIMOTO, Takeaki KAWASHIMA, Soichiro SEKINE, Hirokazu KAJI, Takashi ABE, Matsuhiko NISHIZAWA

Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan

We describe a method to create cell-adhesive regions and to position adherent cells on the newly created regions in sequence within a microfluidic channel. One of the microelectrodes fabricated at the upper wall of the channel was used for locally generating hypobromous acid that renders the channel bottom protein-adsorptive. After the fibronectin was immobilized on the treated region, an ac voltage (20 Vpp, 1 MHz) was applied to the microelectrode array in the presence of suspended HeLa cells. Since a repulsive force of negative dielectrophoresis (DEP) directs the cells toward the weakest region of the nonuniform electric field, the cells were positioned on the fibronectin-patterned region to allow the cell adhesion after the DEP force remained for another 10 min, even in the presence of fluid flow (< 0.1 μL min-1). By repeating the above process, two types of cells could be patterned in the microchannel.

バイオ／ケミカルマイクロプロセッサのための要素技術の検討

Graduate School of Pure and Applied Sciences, University of Tsukuba　
Tsukuba, Ibaraki 305-8573

A microfluidic device and procedures to handle many liquid plugs for bio / chemical analyses were developed. A major part of the device was a
T-junction consisting of a main flow channel and a handling flow channel. Formation of plugs of various lengths, mixing of solutions, and exchanging
the order of plugs could be carried out by using basic procedures including attachment of plugs, division of a plug, and exchange the order of plugs.
Rapid mixing could easily be achieved by moving a plug formed by attaching two plugs back and forth. The device was used for efficient determination of
L-glutamate in solutions of different concentrations or pHs.

物材機構^a、東大CNBI^b

○宮原裕二^ab、坂田利弥^b、松元　亮^b、片岡知歩^a

DETECTION OF BIOMOLECULAR RECOGNITION USING BIOTRANSISTOR

Yuji MIYAHARA^ab, Toshiya SAKATA^b, Akira MATSUMOTO^b and Chiho KATAOKA^a

^a Biomaterials Center, National Institute for Materials Science
1-1, Namiki, Tsukuba, Ibaraki, 305-0044
^b Center for NanoBio Integration, The University of Tokyo
7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656

We have been investigating a new approach to detect molecular recognition events by means of electrostatic interaction between charged biomolecules and electrons in silicon. For genetic analysis, an insulated gate field effect transistor (FET) is used in combination with specific molecular recognition such as allele specific hybridization, intercalation, and primer extension to detect single base difference of target DNA. The hybridization events are followed by the introduction of DNA polymerase and four deoxynucleotides. The sequence-specific extension can be controlled by a match or mismatch at the 3’-end of each oligonucleotide probe. As a result of extension reaction, negative charges increase at the gate surface of the genetic FET because of intrinsic negative charges of polynucleotide. The allele specific primer extension on the gate surface could be directly transduced into electrical signal using the genetic FETs. We demonstrated SNP genotyping and DNA sequencing without any labeling for target DNA molecules.

酵素スイッチング機構を用いたコファクターセンシング

神奈川工科大工・応用バイオ科学科、応用化学科^*

飯田泰広、○野島大佑^*、吉野　翔^*、松本邦男、佐藤生男^*

Cofactor Sensing with Use of Enzyme Switching Mechanism

Yasuhiro IIDA, Daisuke Nojimab^*, Kakeru Yoshino^*, Kunio Matsumoto, and Ikuo SATOH^*

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

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

A spectrophotometric flow-injection analysis (FIA) with use of an alkaline phosphatase (ALP) column was constructed, and the system was applied to investigation of the effect of several metal ions on the enzyme activity and also determination of Zn(II) ions based on the apoenzyme reactivation method. ALP, a kind of typical metalloenzymes, was covalently immobilized onto a gold mesh plate and then, placed into a small polymer cylinder. The FIA system was assembled with the enzyme column and a flow-injection photometric device. Tris-HCl buffer (0.1 M, pH 8.0, 0.1 μM citrate) as the carrier solution was continuously pumped through the system. Sample solutions were introduced into the system via rotary injection valves. A 2,6-Pyridine dicarboxylate solution was injected for removing metal ions from the ALP and p-nitrophenyl phosphate (0.1 mL) as the substrate was injected followed by injection of several concentration of Zn(II) ions. An effect of Mg(II) ions on the reactivation of once deactivated ALP was investigated, and the concentration of Zn(II) ions in real samples was determined with use of the system.

酵素-有機色素吸着PFC電極を用いるアンペロメトリックバイオセンサ

○長谷部靖^a、菅原信也^a、新藤泰弘^a、須田吉久^b、山田邦生^b、金子浩子^c

AMPEROMETRIC BIOSENSORS USING ENZYMES AND ORGANIC DYES-CO-ADSORBED PFC ELECTRODES

Yasushi HASEBE^a, Shinya SUGAWARA^a, Yasuhiro SHINDO^a, Yoshihisa SUDA^b, Kunio YAMADA^b, and Hiroko KANEKO^c

^aDepartment of Life Science and Green Chemistry, Saitama Institute of Technology, 1690 Fusaiji, Fukaya-shi, Saitama 369-0293
^b Gunma Research and development center, Mitsubishi Pencil Co. Ltd.,
1091 Tatsushi, Fujioka-shi, Gunma 375-8501
^c Tsukuba Material Information Laboratory Ltd., 3-23-4, Nimomiya, Tsukuba-shi, Ibaraki 305-0051

Three kinds of oxidases [glucose oxidase (GOx), lactate oxidase(LOx), glutamate oxidase (GLOx)] and horseradish
peroxidase (HRP) were simply co-adsorbed with organic dye-type electron mediators (Md) onto the disk plane of a plastic formed carbon (PFC) electrode (3 mm d.i.). Co-adsorbed Md was quite important not only to facilitate electron transfer between the electrode and the HRP-active center, but also to stabilize the adsorbed oxidase at the electrtode surface. The resulting sensors exhibited very rapid response (< 5 s), high sensitivity and acceptable operational and storage stabilities. The linear
range of the calibration curves of glucose, lactate and glutamate sensors were 0.02 mM to 2 mM (for glucose), 0.2 μM to 40 μM (for lactate) and 0.1μM to 40 μM (for glutamate), respectively. No efficient response was obtained by using glassy carbon (GC) electrode in place of the PFC, probably because a special structure of the edge plane of the PFC is effective for facilitated electron transfer of HRP and for efficient loading of enzymes.

阪大院工

○谷口　翔平、土井　利浩、上松　太郎、桑畑　進

FABRICATION OF NEW GLUCOSE SENSOR USING CdTe QUANTUM DOTS AS FLUORESCENT PROBE

Shohei TANIGUCHI, Toshihiro DOI, Taro UEMATSU and Susumu KUWABATA
Department of Applied Chemistry, Graduate School of Engineering, Osaka University

?Novel sensor that uses the characteristic of CdTe quantum dots (QDs)-different fluorescent intensity with valiant conditions of redox species-was investigated. We have recently found that two states of redox species, reductant and oxidant like ferrocene derivatives provide two types of quenching effect on the fluorescent intensity of CdTe QDs. It allows the QDs to be applied to sensors that can detect the substrates of redox related enzymes. Here we combined CdTe QDs with glucose oxidase as enzyme and ferrocene derivatives as mediators. This system can measure the concentration of glucose according to the fluorescent intensity of the CdTe QDs. In this sturdy, validity of its system as practical Glucose Sensor was evaluated at the point of mainly optically-based measurements and we attend to fabricate visible, low cost, disposable and simplified glucose sensor by fixing the system into the porous materials like agarose gel and polystylene.

マイクロコンタクトプリンティングを用いたオプティカル化学・バイオセンサアレイの作製
　
富山大院理工

野村明孝，山本瑞起，入部康敬，○鈴木正康
　
PREPARATION OF OPTICAL CHEMICAL AND BIO SENSOR ARRAYS BY USING
MICROCONTACT PRINTING
　
Akitaka NOMURA, Mizuki YAMAMOTO, Yasunori IRIBE, Masayasu SUZUKI

Graduate School of Science and Engineering, University of Toyama
Toyama-shi, Toyama 930-8555, Japan

We have developed optical pH and oxygen sensor array by coupling a fluorescent probe dye coated substrate and a micro well array film
prepared with PDMS. In this study, optical chemical sensor array (each sensor spot size was 10μm, pitch 40 μm) was prepared by using the
microcontact printing technique. Micro stamp was prepared with PDMS by using SU-8 micro well array as a mold. Sensor reagents (FITC aqueous
solution for pH sensor array, and ruthenium complex Nafion solution for oxygen sensor array) were stamped onto the diamond like carbon coated
slide glass by a microcontact printer. Fluorescence image showed the optical sensor array was successfully stamped and the averaged spot size
of pH sensor array and oxygen sensor array was 10.5 μm and 8.7 μm respectively. The prepared pH sensor array showed good pH responses in
the range pH 6 - 8. The oxygen sensor array could also detect differences of oxygen concentration.

過酸化水素の高感度クーロメトリック測定と免疫センシングへの応用

兵庫県立大物質理^a、産総研北海道センター^b，産総研つくばセンター^c

○水谷文雄^a，太田栄次^a，三重安弘^a，丹羽　修^c，安川智之^a

HIGHLY-SENSITIVE IMMUNOASSAY SYSTEM USING COULOMETRIC HYDROGEN PEROXIDE SENSOR

Fumio MIZUTANI^a, Eiji OHTA^a, Yasuhiro MIE^b, Osamu NIWA^c and Tomoyuki YASUKAWA^a

^a Graduate School of Material Science, University of Hyogo, Kouto, Kamigori, Hyogo 678-1297
^b Hokkaido Center, National Institute of Advanced Industrial Science and Technology, Tsukisamu-Higashi, Toyohira-ku,
Sapporo 062-8517
^c Tsukuba Center, National Institute of Advanced Industrial Science and Technology, Higashi, Tsukuba, Ibaraki 305-8566

Enhanced sensitivity of hydrogen peroxide was performed by accumulating the charge through the oxidation of [Os(bpy)2] ²⁺ (bpy = bipyridyl) into [Os(bpy)2]³⁺ in a peroxidase-containing polymer layer on an electrode under the open-circuit condition and by measuring the reduction current for [Os(bpy)2]³⁺ after applying a negative potential. The accumulation resulted in a large current response, and the lower detection limit. The detection limit for hydrogen peroxide and that for glucose oxidase (GOD), a hydrogen peroxide-producing enzyme, were 1 nM and 0.2 mU/L, respectively. The proposed measuring method for hydrogen peroxide was applied to the immunoassay of insulin using a GOD-modified anti-insulin antibody. Insulin in the range from 1 to 100 ng/mL could be determined.

ヘテロコア型光ファイバSPRセンサの曲げによる特性変化

創価大工

○関　篤志、髙木圭樹、佐々木博幸、渡辺一弘

EFFECT OF BENDING ON SPR SENSOR BASED ON A HETERO-CORE STRUCTURED FIBER OPTIC

Atsushi SEKI^a, Keiju TAKAGI^b, Hiroyuki SASAKI^b, Kazuhiro WATANABE^b

^a Department of Bioinformatics,
^b Department of Information Systems Science,　Faculty of Engineering, Soka University　1-236 Tangi, Hachioji, Tokyo 192-8577, Japan

Effect of bending to propagating loss on hetero-core structured fiber optic was characterized. In the case that bare fiber was bent, the loss increased according to increasing of the curvature. According to increasing of refractive index of the solution, the effect of the bending increased. In the case of SPR sensor that the all over the sensor surface was covered with metal thin film, it was shown that the alternation of the curvature at the hetero-core portion caused the change of the spectra in the peak strength. In the case that the silver film was deposited in one side of the fiber, in addition, it was shown that the propagating loss depend largely on the curvature of the silver film.

Layer-by-Layer法による電気化学並びに表面プラズモン共鳴免疫センサの作製と応答評価

DEVELOPMENT AND COMPARISON BETWEEN ELECTROCHEMICAL AND SURFACE PLASMON
RESONANCE IMMUNOSENSOR ASSEMBLED WITH THE LAYER-BY-LAYER METHOD

^a National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566,
^b Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503,
^c University of Tsukuba Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8573

We report comparison results between electrochemical enzyme immunosensor and surface plasmon resonance (SPR) based immunosensor on a same gold
sensing surface. The simultaneous electrochemical and SPR measurements were performed on the gold surface modified with multilayer of poly-L-lysine and poly-styrenesulfonate assembled by layer-by-layer method.

ＳＰＲ法による尿中腫瘍マーカー/クレアチニンの同時測定

SIMULTANEOUS ON-CHIP DETERMINATION OF A CANCER MARKER AND CREATININE IN A URINE SAMPLE BY INTEGRATING SURFACE PLASMON RESONANCE SENSOR IN A MICROFLUIDIC CHANNEL

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

This paper reports on chip simultaneous determination of creatinine and cancer marker by surface plasmon resonance (SPR) method. We prepared two gold thin films formed on a glass wafer. In general, sensitivity for small biomolecule such creatinine is not enough in SPR measurement. In order to resolve this issue, we amplified SPR signal by modifying Os-(4,4’-dimethylbipyridine) electron mediator containing horseradish peroxidase (Os(bpy)-HRP) on the SPR sensing surface in a microchannel. Then three enzymes were immobilized on the upstream of the microchannel to convert creatinine to hydrogen peroxide. On the other hand, we modified capture antibody via protein A on the other gold thin film to detect cancer marker (PSA). When injecting a synthetic creatinine solution, slope of SPR sensorgram increased as creatinine concentration was elevated. The linear range of creatinine sensor was from 100μM to 100mM. On the other hand, PSA concentration-dependent SPR shift was observed when injecting PSA solution. Detection limit of this sensor was 100ng/ml, therefore we have to improve the sensitivity because cut off value is 4ng/ml. We detected simultaneous SPR signal of creatinine and PSA successfully when injecting a mixture solution. Thus, we could correct the PSA concentration without being affected by the fluctuating urine concentration since creatinine performs as the compensation substance.

2次元SPRセンサを用いる個々の肥満細胞の応答観測とアレルゲンセンシング

RESPONSE MEASUREMENT OF INDIVIDUAL MAST CELLS USING A 2D-SPR SENSOR AND ITS APPLICAION TO ALLERGEN SENSING

^a Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555,
^b Toyama New Industry Organization, 529 Takada, Toyama 930-0866

Surface plasmon resonance (SPR) biosensor has some advantages such as label-free, real-time and highly-sensitive measurement. Recently SPR signal changes based on the allergen-stimulation response of mammalian cells have been reported. In this paper, we examined to observe the response of a mast cell model, rat basophile leukemia cell (RBL-2H3) upon stimulation with immunoglobulin E (IgE) and the subsequent allergen in single cell level, by using the 2D-SPR imaging sensor. Different responses of each individual cells was clearly observed as the increment of SPR signal (reflection intensity) upon stimulation with 0.1-10μg /mL anti-dinitorophenyl (DNP) IgE or 0.1-1000 ng/mL DNP-modified bovine serum albumin (DNP-BSA). 2D-SPR imaging enables teal-time and simultaneous monitoring of individual cells. Percentages of responded cells increased as the concentration of IgE or antigen increased.

Vol. 24, Supplement A (2008)

Abstracts