トータル炭化水素濃度測定用混成電位型ジルコニアセンサの特性改善

九大院総理工^a、九大産学連携センター^b、学振^c
　
○藤尾 侑輝^a、V. V. プラシニツァ^b、P. エルマレイ^{b, c}、三浦 則雄^b

IMPROVEMENT IN STABILITY OF MIXED-POTENTIAL-TYPE ZIRCONIA-BASED TOTAL HYDROCARBON SENSOR

Yuki FUJIO ^a、Vladimir V. PLASHNITSA ^b、Perumal ELUMALAI ^{b, c}、Norio MIURA ^b

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

We have recently reported that the YSZ (yttria-stabilized zirconia) based sensor attached with ZnCr₂O₄-sensing electrode (SE) can detect the total concentration of various hydrocarbons (HCs) at 550oC under wet condition. However, it was clarified that the sensing performance of the present sensor was not so stable. Thus, we tried to improve the stability of the sensor by the use of a laminated heterolayer-SE consisting of ZnCr₂O₄ and YSZ thick films. As a result, the sensor using the ZnCr₂O₄/YSZ-SE exhibited quite stable response to C₃H₆ for about one month examined. The selectivity and response rate to C₃H₆ was also rather good for the present sensor. In addition, it was confirmed that the modified sensor could measure the total concentration of mixture of various HCs.

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Ni_1-xCo_xO検知極を用いた混成電位型ジルコニアセンサ のNO₂検知特性

九大産学連携センター^a、学振^b、九大院総理工^c

○P. エルマレイ^{a, b}、V. V. プラシニツァ^a、藤尾 侑輝^c、三浦 則雄^a

NO₂ SENSING CHARACTERISTICS OF YSZ-BASED MIXED-POTENTIAL-TYPE SENSOR USING Ni_1-xCo_xO SENSING-ELECTRODE

Perumal ELUMALAI ^{a, b}、Vladimir V. PLASHNITSA ^a、Yuki FUJIO ^c、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

Various compositions of Co-doped NiO samples (Ni_1-xCo_xO, 0.2 ≤ x ≤ 1) were synthesized by citrate-gel method and characterized by XRD, SEM and EDX. Each of Ni_1-xCo_xO samples obtained was utilized as sensing electrode (SE) for yttria-stabilized zirconia (YSZ)-based planar sensor for detection of NO₂ at 800℃ under wet condition. As a result, NO₂ sensitivity was found to increase with increasing Co content in Ni_1-xCo_xO and the maximum sensitivity was observed at x = 0.1. Interestingly, the sensor attached with Ni_0.8Co_0.2O-SE exhibited excellent selectivity to NO₂. The sensitivity of the sensors varied linearly on the logarithm of NO₂ concentration and was almost invariant to the change in water vapor concentration in the sample gas. The sensing mechanism of the present sensor was briefly discussed.

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限界電流式車載用NOxセンサの開発

日本ガイシ(株)

○鬼頭 賢信、中垣 邦彦

LIMITING-CURRENT-TYPE NOx SENSOR FOR AUTOMOTIVE APPLICATION

Kenshin Kitoh, Kunihiko Nakagaki

NGK Insulators, Ltd. 2-56 Suda-Cho, Mizuho-ku, Nagoya-City, Aichi 467-8530

Global warming has recently become a major issue for the future of the global environment, and around the world, the reduction of the greenhouse gases causing global warming is required. Emission-regulations for motor vehicles are becoming more stringent around the world and fuel economy is also strongly required. In order to achieve such requirements, car manufacturers now focus on developing lean burn engines and diesel engines. However, exhaust gas from these engines has relatively higher NOx comparing to a conventional gasoline engine equipped with three way catalyst. Therefore, in order to reduce the NOx from those vehicles, NOx aftertreatment systems, such as NOx storage catalyst and selective catalytic reduction by urea dosing, are also aggressively being developed. For those systems, accurate direct measurement of NOx emission level is very important. NGK Insulators Ltd. has developed limiting-current-type NOx sensor with a zirconia thick-film technology. The NOx sensor is capable of measuring low levels of NOx concentration with high accuracy. The sensor contributes to control and diagnosis of the NOx aftertreatment systems in automotive application.

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ナノ反応場とメソ・マクロ高次構造の設計・制御による機能性ガスセンサ材料の創製

長崎大学

○清水康博

DESIGN OF FUNCTIONAL GAS SENSOR MATERIALS BY CONTROLLING
REACTION ENVIRONMENTS AND MESO- AND MACRO-SUPER STRUCTURE

Yasuhiro Shimizu

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

The present article summarizes our latest studies directed to designing of functional gas sensor materials by controlling reaction environments of gases to be detected and meso- and macro-super structure of sensors providing diffusion paths for the gases including oxygen. The importance of controlling of both the gas reactivity and the gas diffusivity is first proved by the simultaneous measurements of gas responses at the surface and in the interior region of SnO₂-based thick film sensors and gas diffusion behavior from the surface and the interior region. The improvements of gas sensing properties induced by the incorporation of meso- and macro-porous structure in the case of semiconductor gas sensors and by interface control between the Pd-based electrode and anodized TiO₂ films in the case of diode-type sensors are also reviewed.

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半導体ガスセンサのための理論的アプローチ

九大院総理工

島ノ江憲剛、山添　曻

THEORETICAL APPROACH TO THE DESIGN FACTORS IN SEMICONDUCTOR GAS SENSOR

Kengo SHIMANOE and Noboru YAMAZOE

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

Theoretical exploration has been conducted to formulate the response of a semiconductor gas sensor using thin plate-like crystals. Based on the Poisson’s equations, the depth profiles of electric potential inside the component crystals under electron-depleted conditions are solved. By combining this electronic equilibrium with the gas adsorption equilibrium taking place outside, reduced resistance (R/R₀) of sensor device can be expressed as a function of reduced adsorptive strength (X) of the adsorbing gas for the crystals different in reduced size (n). As an important phenomenon typically associated with small crystals, a new type of depletion (volume depletion) appears following the conventional one (regional depletion) on increasing X, and the transition to the volume depletion takes place at smaller X as n decreases. In the stage of volume depletion, R/R₀ is linear to y with a linearity constant inversely proportional to n. In addition, the receptor function can also be formulated over a wide range of depletion from conventional one (regional depletion) to new type one (volume depletion) by focusing attention on how the surface density of adsorbed oxygen ions (O^-) is related with chemical moiety outside the crystals and physical moiety inside.

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SnO₂ガスセンサにおける結晶子径及びドナー密度の影響

九大院総理工

○末松昂一、湯浅雅賀、木田徹也、山添 曻、島ノ江憲剛

EFFECTS OF THE CRYSTALLITE SIZE AND DONOR DENSITY ON THE SENSING PROPERTIES OF SnO₂ GAS SENSORS

Koichi SUEMATSU ^a, Masayoshi YUASA ^b, Tetsuya KIDA ^b, 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

It has been accepted that decreasing of the particle size and doping foreign elements are quite effective in improving the sensitivity of semiconductor gas sensors. Recently, we have proposed some theoretical models that explain the performance of semiconductor gas sensors on the basis of the surface depletion effect in oxide semiconductors. They show that the sensor response of semiconductor gas sensors strongly depends on the crystallite size and the donor density. In this study, to experimentally reveal such explanations, we tried to control the crystallite size and the donor density of SnO₂ by controlling the calcination temperature and Fe³⁺ doping concentration. The electric resistance and sensor response were measured in various partial pressures of oxygen and hydrogen. It was found that the sensor response to hydrogen was increased by Fe³⁺ doping and/or decreasing the crystallite size. The obtained results are discussed in terms of newly proposed theory.

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セリアージルコニア厚膜を使った
抵抗型酸素センサの模擬排気ガス中での応答特性

産総研

○伊豆典哉、申ウソク、松原一郎、村山宣光、伊藤敏雄、西堀麻衣子

RESPONSE PROPERTIES FOR RESISTIVE OXYGEN SENSOR USING CERIA-ZIRCONIA THICK FILM IN MODEL EXHAUST GAS

Noriya IZU, Woosuck SHIN, Ichiro MATSUBARA, Norimitsu MURAYAMA, Toshio ITOH, and Maiko NISHIBORI
Advanced Manufacturing Research Institute, National Institute of Advanced
Industrial Science and Technology (AIST),
Moriyama-ku, Nagoya 463-8560

A resistive oxygen sensor using ceria - zirconia can distinguish fuel rich and lean conditions in the case of a model exhaust gas in an equilibrium state. However, its response is unknown in a model exhaust gas in a nonequilibrium state. In this study, we investigated the response properties of the oxygen sensor in a model exhaust gas in nonequilibrium state. As a result, the following problems were clarified. First, the resistive oxygen sensor showed the output of a propane lean condition in cases where the ratio of propane to oxygen was a rich condition in nonequilibrium state, while the electromotive force sensor using an oxide ion conductor showed the output of a propane rich condition in the same condition. Second, the response of the resistive sensor heated by the self-heater at 600°C was very slow in equilibrium state made by complete combustion when the conditions changed from lean to rich condition. In order to solve these problems, we fabricated the resistive oxygen sensor having Pt catalyst made by new simple process and investigated its response. As a result, we improved the first response problem by optimization of Pt content. That is to say, the sensor can distinguish rich and lean conditions in nonequilibrium state. Furthermore, the response speed was also improved by Pt catalyst.

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TiO₂ナノチュ－ブを用いた有機ガス検知の検討

九大院総理工

○徐 敏鉉、湯浅雅賀、木田徹也、山添　曻、島ノ江憲剛

DETECTION OF ORGANIC GASES USING TiO₂ NANOTUBE-BASED GAS SENSORS

Min-Hyun SEO ^a, Masayoshi YUASA ^b, Tetsuya KIDA ^b, Noboru YAMAZOE ^b, Kengo SHIMANOE ^b
a Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences,
Kyushu University, 6-1 Kasuga Koen, Kasugashi, Fukuoka 816-8580, Japan
^b Department of Energy and Material Sciences, Faculty of Engineering Sciences,
Kyushu University, 6-1 Kasuga Koen, Kasuga-shi, Fukuoka 816-8580 Japan

Preparation and morphology control of TiO₂ nanostructured films were investigated to detect large sized organic gases. A hydrothermal treatment of TiO₂ nanoparticles in a NaOH solution at 230 ℃ for 24 hours and subsequent washing with an HCl solution produced uniform sized TiO₂ nanotubes of 1 μm in length and 50 nm in diameter. The obtained nanotubes were subjected to a ball milling treatment for 3 h to shorten the length of the nanotubes. It was found that the ball-milled nanotubes showed two times higher sensor response to toluene (500 ppm) in air at 500 ℃ than commercial TiO₂ nanoparticles and as-prepared nanotubes. The obtained results suggest that the control of the density and porosity and the crystallite size for TiO₂ nanotube-based sensors are important factors to gain high sensitivity to large organic molecules like toluene.

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β－ジケトン素子を用いたホルムアルデヒド検出装置の開発

NTT環境研^a、国環研^b、東洋大^c

丸尾容子^a、中村二朗^a、山田巧^a、内山政弘^b、泉克幸^c、徳満知^c

DEVELOPMENT OF FORMALDEHYDE MONITORING DEVICE USING DEVELOPED β-DIKETONE SENSOR ELEMENT

Yasuko Y. MARUO^a, Jiro NAKAMURA^a, Takumi YAMADA^a, Masahiro UCHIYAMA^b, Katsuyuki IZUMI^c and Satoru TOKUMITSU^c
aNTT Energy & Environmental Laboratories, Atsugi-shi, Kanagawa 243-0198
^bNational Institute of Environmental Stusies, Tsukuba-shi, Ibaraki 305-8506
^cToyo University, Kawagoe-shi, Saitama 350-0815

We have developed a small formaldehyde-detecting device using newly developed sensor element. The sensor element employs a colorimetric reaction between formaldehyde and a kind of β-diketone (1-phenyl-1, 3-butanedione). We achieved indoor formaldehyde monitoring using the developed device in some buildings and houses. It was found that formaldehyde concentration in one of surveyed buildings related to off-on control of an air-conditioning system.

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交互積層薄膜を形成したヘテロコア型光ファイバのエタノールに対する応答

創価大工

○関　篤志、秋田尚平、佐々木博幸、西山道子、渡辺一弘

FIBER OPTIC ETHANOL SENSOR USING LAYER-BY-LAYER THIN FILM

Atsushi SEKI, Shohei AKITA, Hiroyuki SASAKI, Michiko NISHIYAMA, Kazuhiro WATANABE

Faculty of Engineering, Soka University, 1-236 Tangi, Hachioji 192-8577

We describe an ethanol sensor based on a hetero-core structured fiber optic and layer-by-layer thin film. On the surface of the sensing part, amino group was introduced. In preparing layer-by-layer thin film, sodium polyacrylate or poly(sodium 4-styrene sulfonate) as polyanion, poly (allylamine hydrochloride) as polycation were used, respectively. The fiber had no sooner immersed in the solution, the output changed rapidly. According to increasing of ethanol concentration, the propagating loss increased. The phenomenon indicated that the layer-by-layer thin film was shrunk by ethanol, and the refractive index of the thin film increased, resulting that the propagating wave leaked out from the cladding. Both thin films showed the linear relation in the range of 0-20 %(w/w) ethanol.

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発光材料薄膜に基づく光導波路センサ用光源の開発

横浜国大院工^a、環境情報^b

伊藤公紀^a、○菊池晋平^a、中島啓光^a、雨宮隆^b

DEVELOPMENT OF LIGHT SOURCE FOR OPTICAL WAVEGUIDE SENSOR BASED ON THIN FILM OF LUMINESCENT MATERIAL

Kinimori ITOH ^a, Sinpei KIKUCHI ^a, Hiromitsu NAKAJIMA ^a, and Takashi AMEMIYA ^b

^a Graduate School of Engineering, Yokohama National University, Hodogaya-ku, Yokohama 240-8501
^b Graduate School of Environment and Information Sciences, Yokohama National University, Hodogaya-ku, Yokohama 240-8501

Recently, the optical waveguide sensor with the light source of a luminescent material (Alq3) has been developed to be unnecessary to adjust the angle of the incident light and to analyze spectra of the guided light. However, there is a serious problem of the decay of the luminescence. To prevent the decay, we examined the luminescent material doped with another one (rubrene). The thin films of Alq3 and rubrene-doped Alq3 were deposited on the K⁺ ion exchanged glass substrates. From the comparison of these substrates, it was determined that the optimum value of the dopant concentration for the guided light intensity is 1.8 wt% whereas that for the half-life is 16.9 wt%. Thus, we found that the optimum value for the light source is in the range of 5 to 10 wt%. In conclusion, we succeeded in improving the half-life of the guided light by doping Alq3 with rubrene.

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水素雰囲気中で作動可能なダイオード式COセンサの開発

長崎大工

○森永直樹、兵頭健生、清水康博、江頭　誠

Development of a diode-type CO sensor operable in hydrogen atmosphere

Naoki MORINAGA¹, Takeo HYODO², Yasuhiro SHIMIZU¹ and Makoto EGASHIRA<sup>1

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

CO sensing properties of diode-type sensors using an anodized TiO₂ film and Pd-Pt alloy electrodes (Pd-nPt/TiO₂, n: the amount of Pt addition to Pd (in wt%)) under H₂ atmosphere have been investigated in this study. A Pd/TiO₂ sensor showed no response to 80 ppm CO in H₂, while the CO response of a Pt/TiO₂ sensor was much higher than that of the Pd/TiO₂ sensor. The addition of Pt into Pd was very effective in improving the CO response, and a Pd-64Pt/TiO₂ sensor showed the largest CO response to H₂ among all the Pd-nPt/TiO₂ sensors tested. On the other hand, the response and recovery speeds of the sensors remained almost unchanged by the addition of Pt to Pd.

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酸化物内包多層カーボンナノチューブの二酸化窒素検知特性

立命館大生命

○橋新剛、岸孝宏、玉置純

NO₂ SENSING PROPERTIES OF OXIDE DEPOSITED INSIDE MWNT

Takeshi HASHISHIN, Takahiro KISHI, Jun TAMAKI

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

SnO₂ - MWNT nano composite was fabricated using simple wet chemical deposition. The deposition states of SnO₂ could be controlled by heat treatment conditions. SnO₂ particles were deposited inside as well as outside MWNT when the composite was calcined at 400 ℃ for 3h in air. On the other hand, SnO₂ particles deposited outside MWNT were removed when the composite was sequentially calcined at 600℃ for 3h in Ar. Moreover, sensing property of SnO₂ - MWNT composite sensor to 1 ppm NO₂ was investigated. As a result, it was clarified that NO₂ sensing properties were intensively affected by deposition states of SnO₂ on MWNT because of the formation of p-n junction. Especially, SnO₂ deposited inside MWNT sensor showed the excellent NO₂ sensing properties. The p-n junction contributed to form large depletion layer on the inner surface of MWNT, the depletion layer penetrated to outside MWNT, and the amount of NO₂ adsorption on MWNT was increased. It is suggested that modification with semiconductor oxides is very useful to enhance the sensing properties of CNT.

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FET型NO₂センサにおけるNaNO₂系 検知補助相への貴金属添加量の影響

九大院総理工

○井上 浩文、湯浅 雅賀、木田 徹也、山添 曻、島ノ江 憲剛

EFFECTS OF THE LOADING AMOUNT OF NOBLE METAL INTO AN NaNO₂-BASED SENSING LAYER
ON THE PROPERTIES OF FET-TYPE NO2 SENSORS

Hirofumi INOUE ^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-shi, Fukuoka 816-8580

NaNO₂-based auxiliary layers including Ruthenium (Ru) or platinum (Pt)-loaded WO₃ were developed as new sensing materials for a FET-type NO₂ sensor in order to improve its response- and recovery-speeds to NO₂. The dependence of the loading amount of noble metal on the NO₂ sensing performance was investigated in detail. Among the devices examined, the FET-device fitted with a Ru (0.1 wt%) /WO₃-NaNO₂ layer was found to show the best response- and recovery-speeds in response to 500 ppb NO₂ at 130℃.

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Ｓｉ-ＭＯＳＦＥＴ型水素センサの寿命評価とそのメカニズム

日立基礎研

○宇佐川 利幸、 菊池 洋太

LIFE TIME EVALUATION OF Si-MOSFET HYDROGEN SENSORS

Toshiyuki USAGAWA , Youta KIKUCHI

Advanced Research Laboratory, Hitachi, Ltd., Kokubunnji-shi, Tokyo 185-8601

Developed Pt-gate Si-MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) hydrogen-gas sensors have several advantages such as: (1) Low temperature operations (100-150℃), (2)　Low voltage & low power operations (suitable for electric battery operations), (3) Easy down sizing (high potential to achieve ultra low power operations based on Si-LSI technology), (4) air free operations, (5) small and compact sizes, comparing with commercially available hydrogen gas sensors. These characteristics would be suitable for protecting the safety of coming hydrogen society. We introduce phenomenological evaluation methods of intrinsic life times for developed sensor chips by using Arrhenius plots to analyze accelerated temperature and humidity aging experiments. The intrinsic life times are related to the degradations of gate metal regions, source-drain regions, and Al wiring-heater in sensor chips. Hydrogen responding amplitudeΔVg is tough enough for accelerated temperature up to 475 ℃、which is nearly the breakdown temperature of FET characteristics. The degradation of source drain leak currents or electrical resistance of Al wiring-heater are caused by diffusion of constituent doped Si or Al atoms themselves. Unexpectedly the intrinsic life times of sensor chips are estimated to be large enough more than ten years.

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マイクロコンタクトダブルプリンティングによるオプティカル化学・バイオセンサアレイの集積化

富山大院理工

○鈴木　正康、野村　明孝、入部　康敬

INTEGRATION OF OPTICAL CHEMICAL- AND BIOSENSOR ARRAY BY MICROCONTACT DOUBLE PRINTING

Masayasu SUZUKI, Akitaka NOMURA and Yasunori IRIBE

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

The integrated optical pH and oxygen sensor array on which pH and oxygen sensor spots whose diameter is 10μm were arranged alternately on one chip, was developed by using microcontact “double” printing. FITC based pH sensor and ruthenium complex based oxygen sensor was stamped onto a DLC sputtered slide glasses. After the printing of oxygen sensor spots, pH sensor spots were stamped between oxygen sensor spots by using the same PDMS stamp. The response was measured by using a micro array scanner. pH sensor spots responded to only pH changes and oxygen sensor spots responded to only oxygen concentration changes. Furthermore glucose oxidase membrane (10μm i.d.) was stamped onto the oxygen sensors (10μm i.d.) prepared by microcontact printing. The prepared glucose sensor array showed quantitative responses to glucose.

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モレキュラーインプリントポリマー修飾電極による、Bisphenol A センシングシステムの検討

（創価大工）

○横田　宣之、河東田　武夫、渕脇　雄介、金松　知幸、久保　いづみ

STUDY OF THE SENSING SYSTEM FOR BISPHENOL A UTILIZING A MOLECULARLY
IMPRINTED POLYMER MODIFIED ELECTRODE

Nobuyuki Yokota, Takeo Katoda, Yusuke Fuchiwaki, Tomoyuki Kanamatsu, Izumi Kubo

Faculty of engineering, Soka University 1-236 Tangi-cho ,Hachioji ,Tokyo


Preparation of molecularly imprinted polymer (MIP) layer on a gold electrode plate was investigated in order to establish a simple and rapid bisphenol A (BPA) sensor system. MIP for BPA was polymerized from pre-polymer cocktail composed of 4-vinylpyridine (4-VPY), ethylene glycol dimethacrylate（EDMA）and BPA. It was spin-coated on the surface of the gold electrode and polymerized as a thin layer by UV light- irradiation for 2 and 5 min. The surface of MIP modified electrode and bare gold electrode was observed with atomic force microscopy and the MIP modified electrode was apparently different from the gold electrode. BPA was electrochemically oxidized around 580 mV vs. Ag/AgCl reference electrode with the gold electrode and the MIP modified electrode prepared in this study. This electrode can be served as BPA sensor and the anodic current of BPA depended on its concentration at the range of 5-15 μM. Furthermore, we tried to detect BPA (5 μM) in the serum of rat with the use of BPA sensor, and anodic current response of BPA around 580 mV was confirmed.

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電気泳動法による酵素固定化条件がグルコース応答特性に及ぼす影響

長崎大¹院生産科学，²工

○吉田衣里¹、兵頭健生¹、清水康博²、江頭　誠²

EFFECTS OF ENZYME IMMOBILIZATION CONDITIONS BY ELECTROPHORESIS ON THEIR GLUCOSE SENSING PROPERTIES

Eri YOSHIDA¹, Takeo HYODO¹, Yasuhiro SHIMIZU² and Makoto EGASHIRA²

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

Glucose sensing properties of a macroporous (mp-) Pt electrode immobilized with glucose oxidase (GOD) by electrophoresis were investigated in this study. The mp-Pt was obtained by electrolytic deposition of Pt on a polymethylmethacrylate (PMMA) template film and subsequent removal of PMMA at 400oC. The PMMA template film had comparatively ordered three-dimensional (3D) array structure, and then the resulting mp-Pt film showed submicron-sized porous structure reflecting the template film. GOD was immobilized on the surface of mp-Pt electrode by electrophoresis at 0~+5.0 V vs. Ag/AgCl in a GOD aqueous solution at pH = 7.1. Among all the electrodes tested, the mp-Pt electrode immobilized with GOD at +1.0 V showed the highest glucose response with fast response and recovery speeds, probably because of the suitable amount of GOD immobilized on the Pt surface with enhanced adhesion by the electrophoresis.

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共有結合型グルコースインプリント高分子電極のセンサ特性の評価

芝浦工大

○吉見 靖男、成松 明哲、中山 恵介

EVALUATION OF SENSING PROPERTY OF GLUCOSE-IMPRINTED ELECTRODE BASED ON COVALENT BINDING

Yasuo Yoshimi, Akisato Narimatsu and Keisuke Nakayama

Department of Applied Chemistry, Shibaura Institute of Technology. Koto-ku, Tokyo 135-8548

We are developing an electrochemical glucose sensor using a polymer imprinted covalently by glucose. Glucose was allowed to bind with 4-vinylphenyl boronic acid by dehydration. The conjugate copolymerized with crosslinking monomer, which was N,N’-methylene bisacrylamide (MBAA), 1,4-bis(acryloyl)piperazine (BAP) or triethyleneglycol dimethacrylate (TEDMA) with grafting on acrylated electrode. The electrode was washed with hydrochloric acid to remove the glucose as a template. Cyclic voltammetry of ferrocyanide was performed with the electrode. The anodic current was increased by glucose at the glucose-imprinted polymer using hydrophilic crosslinker MBAA. However it was increased using hydrophobic TEDMA. The anodic current at the electrode using MBAA and TEDMA was more sensitive to glucose rather than to fructose.

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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モノマー／鋳型間相互作用に関する考察

芝浦工大

○吉見 靖男、旗持 明利

SPECULATION OF ROLE OF THE AFFINITY BETWEEN TEMPLATE AND FUNCTIONAL MONOMER
IN THE GATE EFFECT OF MOLECULARLY IMPRINTED POLYMER

Yasuo Yoshimi and Akitoshi Hatamochi
Department of Applied Chemistry, Shibaura Institute of Technology. Koto-ku, Tokyo 135-8548

The affinity between the template and the functional monomer is thought to be the most important factor 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 itaconic acid (IA) was analyzed by NMR. The peak of the primary amine of PAA shifted by the presence of IA. The degree of the shift was saturated at the molar ratio of PAA:IA=1:6. A MIP was grafted on indium-tin oxide (ITO) using with L- (or D-) PAA as a template and IA as a functional monomer. Cyclic voltammetry was performed using the ITO as a working electrode. Chiral sensitive change of the anodic current was observed at the molar ratio of PAA:IA=1:2 or 1:4. The discrepancy may be caused by interaction between the template and crosslinker which was the main component.

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金属ナノ粒子修飾炭素電極を用いたヒ素系びらん性有毒ガスセンサの開発

熊本大院工¹、科学警察研究所²、理研計器(株)³

○西山勝彦¹、山田洋行¹、岸慎太郎²、佐藤啓太²、松浦宏昭³、中野信夫³、瀬戸康雄²、谷口　功¹

DEVELOPMENT OF ELECTROCHEMICAL GAS SENSOR FOR BLISTER AGENT HAVING
ARSENIC USING CARBON ELECTRODE MODIFIED WITH METAL NANO PARTICLES

Katsuhiko NISHIYAMA ¹, Hiroyuki YAMADA ¹, Shintaro KISHI ², Keita SATO ² ,
Hiroaki MATSUURA ³, Nobuo NAKANO ³, Yasuo SETO ² , Isao TANIGUCHI ^1
1Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology,
Kumamoto University,2-39-1, Kurokami, Kumamoto 860-8555
²National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa 277-0882
³Riken Keiki Co., Ltd., 2-7-6, Azukizawa, Itabashi-ku 174-8744

Selectivity and sensitivity of electrochemical gas depend on the surface properties of the electrode. Carbon is one of the most popular electrode materials for its safety, wide potential range, and cost. Recently, we reported that a compact type of electrochemical sensor to detect blister agents such as mustard gas (HD) using the carbon electrode modified with gold nano particles, since the effective electrochemical sensor for the blister agents has not been carried out.⁴). In the present study, we will report on the development of leuicite 1 (L1) containing As using carbon electrode modified with metal nano particles. The sensitivity of the sensor depended on the kind of carbon materials and the amount of modified gold, and the electrode potential. On the carbon paper electrode (ca. 6.2 cm²) modified with 12.8 µg of gold nano particles at 0.2 V vs. gold black in 9 M H₂SO₄, ca 1 µA of oxidation current was observed for 9.5 mg m^-3 of L1 gas with the flow rate of 300 ml min^-1 The response current decreased with the decrease of the amount of modified gold. We found that 1 µg of gold nano particle was required for the detection of 9.5 mg m^-3 of L1 gas. The linear relationship of the current vs. [L1] was obtained with the range between 1 and 9.5 mg m^-3 of L1. By using the sensor prepared in this study, we can detect 1.5 mg m^-3 which is required concentration for L1 gas detection.

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フィードバック機能による微小銀／塩化銀参照電極電位の安定化

筑波大院数理物質

○安達貴広、 福田淳二、 鈴木博章

MINIATURIZED REFERENCE ELECTRODE WITH A NEGATIVE FEEDBACK FUNCTION FOR POTENTIAL STABILIZATION

Takahiro ADACHI, Junji FUKUDA, and Hiroaki SUZUKI
Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573

A mechanism to stabilize the potential of an integrated miniature reference electrode by negative feedback was developed. A three-electrode system consisting of three Ag/AgCl electrodes was used and was controlled by a potentiostat. The electrode to provide the standard potential was used as the reference electrode, which was surrounded by a Ag/AgCl auxiliary electrode. When the reference electrode potential changed in response to changes in the concentration of chloride ions, large current was generated on the working electrode and at the same time on the auxiliary electrode. As a result, the concentration of chloride ions around the reference electrode recovered to the initial value, which also caused the recovery of the potential.

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ASOD固定化物を用いた銅(II)イオンのカロリメトリックバイオセンシング

神奈川工科大^{a, b}

佐藤　生男^a，○小林　由樹^a，　飯田　泰広^b

CALORIMETRIC BIOSENSING FOR COPPER(II) IONS USING IMMOBILIZED ASOD-PREPARATIONS

Ikuo SATOH ^a, Yoshiki KOBAYASHI ^a and Yasuhiro IIDA ^b

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

Ascorbate oxidase(ASOD)-immobilized preparations onto porous glass beads were packed into a plastic column and then, the column was attached to a temperature probe. The probe was subsequently attached to a flow-injection calorimetric sensing system. Microdetermination of copper(II) ions was based on an apoenzyme reactivation method and enzymatic activities were calorimetrically monitored by injecting 10.0 mM _L-ascorbate solution(pH 5.6). Exposing the column to N,N,-diethyldithiocarbamate solution(DDTC; pH 8.0) significantly decreased the catalytic activity of the column. Subsequent injection of 1.0 mM copper(II) ions solution(pH 6.0) led to reactivation of the deactivated column. Thus, copper(II) ions in submillimolar levels could be calorimetrically determined.

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　　自己組織化単分子膜を用いた参照用電界効果
トランジスタセンサのpH・イオン応答

早大理工^a、(株)堀場製作所^b

○黒岩 繁樹^a、王 進平^a、山内 悠^b、野村 聡^b、逢坂 哲彌^a

PH AND IONIC-STRENGTH RESPONSES OF REFERENCE FIELD EFFECT
TRANSISTOR MODIFIED BY SELF-ASSEMBLED MONOLAYER

Shigeki Kuroiwa ^a, Jingping Wang ^a, Hisashi Yamanouchi ^b, Satoshi Nomura ^b, and Tetsuya Osaka ^a

^aInstitute for Biomedical Engineering, Waseda University,Tokyo 162-0041
^b HORIBA, Ltd.,Kyoto 601-8510

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. In this study, a light-addressable potentiometric sensor (LAPS) modified by a self-assembled monolayer (SAM) of octadecylsilane (ODS) was pH-insensitive (-1.5 mV/pH), but it was sensitive to ionic strength as was reported in polymer-gate FETs. Our purpose was to make clear the problems of the evaluation methods of ODS-SAM FETs concerning pH and ionic responses and the effect of the surface morphology to improve a reference SAM-FET. ODS-SAM LAPSs and FETs were deposited under different conditions. pH and ionic responses, roughness measured by atomic force microscope, and contact angle (CA) were greatly changed by the difference in morphology of the ODS-SAM. ODS coagulation raises the CA, and the state of hydroxyl groups on the surface also affects the CA. ODS coagulation caused the pH response with the ODS-SAM but decreased the ionic response of the LAPS. Controlling the surface morphology of the ODS-SAM is important to suppress the pH and ionic sensitivities for an in vivo-applicable reference FET.

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イオン液体 1-hexyl-3-methylimidazolium bis(pentafluoroethanesulfonyl) amid塩橋の
基礎特性とフタル酸水素イオンの影響

堀場製作所^a、京都大学^b

○芝田　学^a、桑本　恵子^a、岩本　恵和^a、野村　聡^a、西　直哉^b、垣内　隆^b

THE FUNDAMENTAL PROPERTIES AND THE INFLUENCE OF HYDROGEN PHTHALATE ION ON 1-HEXYL-3-METHYLIMIDAZOLIUMl
BIS(PENTAFLUOROETHANESULFONYL) AMID SALT BRIDGE

Manabu SHIBATA ^a, Keiko KUWAMOTO ^a, Yasukazu IWAMOTO ^a, Satoshi NOMURA ^a, Naoya NISHI ^b, and Takashi KAKIUCHI ^b

^a Core technology, R&D center, HORIBA,Ltd., Kyoto-shi, Kyoto 601-8510
^b Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University,Kyoto-shi, Kyoto 615-8510

We have confirmed that 1-methyl-3-octylimidazolium bis(trifluoromethanesulfonyl)amide (C₈mimC₁C₁N) works well as an ionic liquid(IL)-type salt bridge for the pH measurement. We also found that the liquid junction potential (LJP) at a phthalate buffer was lower by 4mV than other buffers (a phosphate, borate, and citrate). This is because the hydrogen phthalate ions (Hph^-) dissolute to C₈mimC₁C₁N. So, we used 1-methyl-3-hexylimidazolium ion (C₆mim⁺) as the cation of IL in order to shift the standard ion transfer potential to more positive direction than that of C₈mim⁺ and combined C₆mim⁺ with (CF₃SO₂)₂N^- ion (C₂C₂N^-) so that the solubility of the ionic liquid to water is not changed, and then confirmed that C₆mimC₂C₂N can reduce the influence of the hydrogen phthalate ion.

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集積化マイクロセンシングデバイスの研究開発と
その生体試料応用

独立行政法人産業技術総合研究所

○栗田 僚二

Development of Integrated Micro-sensing Devices and Their Applications to Biological Sample Measurements

Ryoji Kurita

National Institute of Advanced Industrial Science and Technology

We have developed electrochemical and surface plasmon resonance (SPR) based micro-fluidic devices for biological samples. We used a micromachining technique to fabricate amperometric devices for neurotransmitter detection. We achieved high collection efficiency and current response on an electrode by integrating osmium bipyridine electron-mediator modified carbon electrodes, dual film electrodes for differential measurement and interdigitated array electrodes into a micro channel. Low detection limit was obtained with a high temporal and spatial resolution. We could monitor L-glutamate and histamine concentration changes near cultured cells. Furthermore, by combing with a micro dialysis probe, we succeeded in simultaneous in vivo measurement of glucose and lactate concentration in a rat brain. We also developed micro immunoassay devices designed to determine a trace level disease marker protein in blood. The immuno-device is based on the highly sensitive measurement of acetylcholine esterase activity used for antibody labeled enzyme by monitoring the real-time SPR angle change caused by thiocholine accumulation on a gold surface in a T-shaped microfluidic device. We succeeded in measuring 5 pg/mL (15 fg in 3 μL) B-type natriuretic peptide within 30 min.

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固定化グリコーゲンホスホリラーゼb充填カラムを用いたエフェクターのバイオセンシング

神奈川工科大

佐藤　生男、 ○新井　慎也

BIOSENSING OF　EFFECTORS USING AN IMMOBILIZED-GLYCOGEN PHOSPHORYLASE b COLUMN

Ikuo SATOH and　 Shin-ya ARAI

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

Glycogen phosphorylase b immobilized onto porous glass beads was packed into a plastic column and then, the column was attached to a flow-injection monitoring system. Injecting substrate solutions containing 5.0 % glycogen and glucose 1-phosphate (G 1-P) with adenosine monophosphate (AMP) as the effector for the enzymes into the system formed orthophosphate, which was spectrophotometrically detected with a malachite green method. Increases in absorbance at 650 nm with increase in AMP with various concentrations were observed. Thus, the effector in submillimolar levels could be determined.

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極微量溶液プラグのクーロメトリック分析

筑波大数理物質 ^a、Joseph Fourier University ^b

○佐々 文洋 ^a , Hind Laghzali ^b , 福田 淳二 ^a , 鈴木 博章 ^a

Coulometric detection of an analyte in a liquid plug

Fumihiro Sasa ^a, Hind Laghzali ^b, Junji Fukuda ^a, Hiroaki Suzuki <sup>a

a</sup> Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573
^b Depatement of Information Technologies for Health Care, Institute for Science and Technology,
Joseph Fourier University, Grenoble, France BP 53 - 38041

Applicability of coulometric detection was tested for the analysis of compounds in a nano-liter scale liquid plug confined in a PDMS microflow channel. A plug of an appropriate length prepared in a main flow channel was placed on a thin-film three-electrode system formed on a glass substrate. Hydrogen peroxide was detected as a model analyte. When the height of the flow channel was less than 80 μm, the analyte in the plug was consumed rapidly and the generated charge leveled off within 60 s. On the other hand, a substantial amount of the analyte was left, suggesting that there is enough room to improve the sensitivity and detection limit. A clear linear relationship was observed between the generated charge and the concentration of hydrogen peroxide. The device was also tested in the detection of L-glutamate.

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化学的マイクロポンプと微小流路ネットワークによる送液プログラミングとその化学分析への応用

筑波大院数理物質

○高島 篤司、福田 淳二、鈴木 博章

CHEMICALLY ACTUATED MICROPUMPS AND PROGRAMMING USING A MICROFLUIDIC NETWORK AND ITS APPLICATION TO CHEMICAL SENSING

Atsushi TAKASHIMA, Junji FUKUDA, and Hiroaki SUZUKI

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

A microfluidic device that works autonomously without external electrical signals was fabricated. The device consisted of chemically actuated micropumps and microfluidic networks. The operation of the micropumps was based on the volume change of oxygen bubbles produced as a result of catalytic decomposition of hydrogen peroxide. A hydrogen peroxide solution was transported through the flow channel for programming by capillary action spontaneously, which switched the micropumps on sequentially. Solutions stored in the upper reservoir for the respective micropumps could be injected into a main flow channel. Timing for triggering the pumping action could be adjusted by changing the length of the programming flow channel for the hydrogen peroxide solution. In other words, information of the program could be written on the device in the form of the network of flow channels. The applicability of the concept was also tested in a microfluidic device fabricated for chemical sensing.

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電気化学バイオリソグラフィー搭載のマイクロ流路システム

東北大院工 ^a、JST-CREST ^b

橋本昌彦^a、梶弘和^ab、○西澤松彦^ab

ELECTROCHEMICAL BIOLITHOGRAPHY-BASED MICROFLUIDIC BIOCHIP SYSTEM

Masahiko HASHIMOTO ^a, Hirokazu KAJI ^ab, and Matsuhiko NISHIZAWA <sup>ab

a</sup> Graduate School of Engineering, Tohoku University, 6-6-1 Aramaki, Sendai 980-8579
^b JST-CREST Sanbancho, Chiyoda-ku, Tokyo, 102-0075

Cytological examination of leucocytes and smear tests of blood samples are useful for the diagnosis of inflammatory diseases. In spite of the development of a flow cytometry technique that can automatically count and classify blood cells, the examination of peripheral blood smears is still important because direct observation of cells can identify more subtle changes in leucocytes in response to foreign substances such as pathogens. However, preparation of blood smears is time-consuming and labor-intensive because they are manually prepared on glass slides individually.
We have previously reported a method to create a patterned surface inside a microchannel by electrochemical means, "electrochemical biolithography", which enables site-specific immobilization of proteins after the dev ice is fully assembled[1-3]. Here, we present a strategy for the rapid capture of neutrophils from mixed leucocytes by combination with negative dielectrophoresis(DEP).

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超多点電気化学測定システムの構築

東北大院環境

○梅村太三、高橋康史、伊野浩介、珠玖仁、末永智一

DEVELOPMENT OF ULTRA-MULTIPOINT ELECTROCHEMICAL DETECTION SYSTEMS

Taizou UMEMURA, Yasufumi TAKAHASHI, Kosuke INO, Hitoshi SHIKU, and Tomokazu MATSUE

Graduate School of Environmental Studies, Tohoku University, Sendai

We developed a new device for the purpose of comprehensive electrochemical detection on a single chip. 32 × 32 column and row electrodes were arranged orthogonally and the devices comprised as many as 32 × 32 crossing points. Individual crossing point consists of a well in order to trap bioparticles or cells by electrophoresis and two different types of electrodes. First, polystyrene beads, mouse myeloma cells and alkaline phosphatase-modified polystyrene beads (ALP beads) were trapped by electrophoresis. After trapping ALP beads, electrochemical responses using enzyme reaction at individual points were detected　on the basis of redox cycling of localized electroactive species occurring between the electrodes. The results indicate that this device enables us to trap and detect a lot of sample and coincidentally.

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分岐鎖アミノ酸計測用電気化学酵素センサの設計・開発

富山大院理工

○寺村 一孝、篠原 寛明、須加 実

DESIGN AND DEVELOPMENT OF ELECTROCHEMICAL ENZYME SENSOR
FOR BRANCHED-CHAIN AMINO ACIDS

Kazutaka TERAMURA, Hiroaki SHINOHARA and Minoru SUGA
Graduate School of Science and Engineering, University of Toyama 3190 Gofuku, Toyama 930-8555

In this paper, an electrochemical enzyme sensor was designed for branched-chain amino acids as important metabolic compounds. Leucin (Leu) dehydrogenase and diaphorase both were immobilized onto a gold disk electrode via polymer chain. CV measurement and amperometric measurement with the developed amino acid sensor demonstrated the increase of catalytic oxidation current which depended on the Leu concentration. The detection range of Leu by CV method was 20～200μM and that by amperometric detection was 2μM ～1.0mM. The enzyme sensor showed high specificity for not only Leu, but also Val and lie, though little response was measured for other amino acids. These results indicated that this sensor has sufficient potential for a branched-amino acids sensor.

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半導体化学センサを用いた流路内2点同時計測による酵素反応測定

東北大工 ^a, 医工 ^b

吉田 碧里^a, ○宮本 浩一郎^a, Torsten Wagner ^b, 加納 慎一郎^a, 吉信 達夫^a,b

Multi-point measurement of enzymatic reactionin a fluidic channel using chemical sensor

Midori Yoshida ^a, Ko-ichiro Miyamoto ^a,Torsten Wagner ^b, Shin'ichiro Kanoh ^a, Tatsuo Yoshinobu ^a,b
a Department of Electronic Engineering, Tohoku University,6-6-05 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
^b Department of Biomedical Engineering, Tohoku University,6-6-05 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan

The light-addressable-potentiometric-sensor (LAPS) is a chemical sensor based on semiconductor with an electrolyte (E) - insulator (I) - semiconductor (S) structure. Due to the capability of multi-point　measurement, a plurality of sensor functions can be integrated on a single chip of LAPS. In this study, we applied LAPS for differential　measurement of enzymatic reaction, in which two measurement points in the upstream and the downstream of an enzyme reaction chamber were simultaneously monitored by two laser beams modulated at different　frequencies. The reaction time was controlled with the flow rate and the concentration of urea were successfully determined in the range of 10^-4 to 10^-1 M urea was detected.

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オプトード型光ファイバ酸素センサの長期安定性

横浜国大工^a、東京大学先端科学技術研究センター^b、電源開発株式会社^c

中村 祐樹^a、瀬古 裕也^a、伊藤 大輔^a、横山 隆^a、○岡崎 慎司^a、中川 英元^b、新井 隆^c

LONG-TERM STABILITY OF AN OPTODE-TYPE FIBER-OPTIC OXYGEN SENSOR
USING RUTHENIUM COMPLEX IN HARSH ENVIRONMENTS

Yuki NAKAMURA ^a , Yuya SEKO ^a , Daisuke ITO ^a ,Takashi YOKOYAMA ^a , Shinji OKAZAKI ^a,
Hidemoto NAKAGAWA ^b and Takashi ARAI <sup>c

a</sup> Faculty of Engineering, Yokohama National University Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501, Japan
^b Research Center for Advanced Science and Technology, Tokyo University Komaba 4-6-1, Meguro-ku, Tokyo 153-8904,Japan
^c Electric Power Development Co.,Ltd. Ginza 6-15-1, Chuo-ku, Tokyo 104-8165, Japan

The long-term stability of a fiber-optic oxygen sensor was investigated. The sensing mechanism is based on quenching of luminescence by oxygen. Ruthenium complex whose counter-anion is dodecyl sulfate was used as fluorescence dye and two kinds of sensing films was immobilized on quartz substrate by spin-coating method. The end face of an optical fiber probe was placed near the film and fluorescence at 610 nm was measured. Degradation tests were conducted in hot water at 80 degrees Celsius. There was almost no change in sensitivity of the Ru complex deposited film. On the other hand, the sensitivity of Ru complex homogenously dispersed into the silicone resin film was considerably affected by the immersion in hot water. This phenomenon would result from the swelling-shrinking behavior of silicon resin. In order to improve the stability, silicone overcoat as protective film was applied to the Ru complex deposited film. Although the response speed decreased by a factor of 20 compared to that of the sensor without protective film, the sensitivity was almost stable for 50 days in simulated ground water utilized as degradation test solution.

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光吸収型表面プラズモン共鳴を用いた酵素活性のセンシング

オムロン株式会社

戸谷真理子、山本和夫、○岩坂 博之

SENSING OF EMZYME ACTIBITY UTILIZING AN ABSORPTION-BASED SURFACE PLASMON RESONANCE SENSOR

Mariko TOYA, Kazuo YAMAMOTO, Hiroyuki IWASAKA

Omron Corporation, Core Technology Center, Kizugawa-shi, Kyoto, 619-0283

It was described in some articles that the surface plasmon resonance (SPR) sensors was effective to detect optical absorption of small amount of chemicals. We demonstrated to detect the optical absorption by utilizing SPR, and determined enzyme activity of aspartate aminotransferase. In this experiment, we observed physical adsorption of dyes on the thin metallic surface (sensing layer), and found the absorbance enhancement of dyes. We can expect higher sensitivity by applying physical adsorption.

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Shuyan GAO^a, Naoto KOSHIZAKI^a, Emiko KOYAMA^a, Hideo TOKUHISA^a, Takeshi SASAKI^a,
Yoshiki SHIMIZU^a, Jae-Kwan KIM^b, Youngsong CHO^b and Deok-Soo KIM^b

^a Nanotechnology Research Institute, AIST, Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
^b Department of Industrial Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-ku, Seoul 133-791, Korea
E-mail: koshizaki.naoto@aist.go.jp

Metallic nanoparticles embedded in an insulating matrix have recently attracted a lot of research interest. The physicochemical nature of the guest and host components and the synergy between these components endow them with higher functionality and performance, such as relative stability against aggregation, tunable surface plasmon resonance, third-order nonlinear susceptibility, electron tunneling, photoelectrode properties, and so on. Thus, design and construction of such nanocomposites facilitate manipulating material properties through tailoring the kinds, accessibility, and ratios of the components. However, the bottlenecks restricting them from application are (1) how to increase the number density of metallic nanoparticles, and (2) how to improve their stability in various solvents. Herein, Au nanoparticles embedded in Al₂O₃ matrix with tunable density were demonstrated as an example, which were rationally prepared by radio frequency magnetron co-sputtering. Compared with the previous case), the number density of gold nanoparticles has been greatly increased from 14000 μm^-2 to 24000 μm^-2 and the interparticle separation gap (edge-to-edge) has been correspondingly decreased from 8 nm to 5 nm. The most important improvement is the relatively high stability in commonly used solvents, such as water, ethanol, acetone, and acetonitrile. All these advantageous features will facilitate their applications in surface plasmon resonance (SPR) biosensors. Here the improved stability and detection sensitivity of the nanocomposite amplified-SPR transducer for sensing biotin-streptavidin interaction demonstrates that the obtained nanocomopsite film can be a stable and effective platform for SPR sensing.

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表面濃縮機能を有する電気化学発光法

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 CHEMILUMINESENCE WITH SURFACE ACCMULABLE MOLECULES

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

Thiocholine is useful as a coreactant of electrogenerated chemiluminescence because the strongest emission yet reported was observed in a low concentration region. This is because its bi-functional properties include both surface accumulation and luminescence acceleration. This result is important for analytical chemistry since thiocholine can be combined with various biosensing and biochip systems such as DNA and immunoassay systems.

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シスプラチンの電解析出を利用したDNAの高感度測定

兵庫県立大院物質理

○水谷文雄，吉本有希，安川智之

HIGHLY-SENSITIVE DETERMINATION OF DNA BASED ON THE CATHODIC DEPOSITION OF CISPLATIN

Fumio MIZUTANI, Yuki YOSHIMOTO and Tomoyuki YASUKAWA

Graduate School of Material Science, University of Hyogo,
Kouto, Kamigori-Cho, Hyogo 678-1297

A novel electrochemical technique for DNA detection has been developed by a simple combination cisplatin and a glassy carbon electrode. The complexation of cisplatin with DNA caused to suppress the electroreduction of cisplatin owing to the steric hindrance and, subsequently, the electrolytic current for reducing proton that is catalyzed by the platinum deposited on the glassy carbon electrode by the electoreduction of cisplatin. Thus the DNA content was determined from the decrease in the catalytic activity of the electrode: an enhanced current response for measuring the current for reducing proton as compared with that for reducing cisplatin itself could provide the highly sensitive measurement of cisplatin. The detection limit for herring DNA was as low as 0.1 ng/mL.

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導電性ナノカーボン薄膜電極によるDNAのシトシンメチル化の直接電気化学計測

筑波大^a、産総研^b、東工大^c、MESアフティ^d

○後藤圭佑^a,b、加藤大^b、関岡直行^a,b、上田晃生^a,c、栗田僚二^b、廣野　滋^d、丹羽修^a,b,c

Direct Electrochemical Detection of DNA Methylation by Using Nano-carbon Film Electrodes

Keisuke GOTO ^a,b, Dai KATO ^b, Naoyuki SEKIOKA ^a,b, Akio UEDA ^a,c, Ryoji KURITA ^b, Shigeru HIRONO ^d, and Osamu NIWA ^a,b,c

^a University of Tsukuba 1-1-1　Tenno-dai, Tsukuba, Ibaraki, 305-8571
^b National Institute of Advanced Industrial Science and Technology(AIST) 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566
^c Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503
^d MES-Afty Corporation, 2-35-2 Hyoe, Hachioji, Tokyo 192-0918

We developed a nanocarbon film by employing the electron cyclotron resonance (ECR) suputtering method. This ECR nanocarbon film exhibits excellent electrochemical properties such as a wide potential window, a low background current, and high electrode activity for various biomolecules. These properties enable us to detect the cytosine and methylcytosine by direct electrochemical oxidation.In this study, we measured oligonucleotides that are constracted a fragment of the tumor suppressor retinoblastoma (RB1) gene containing two methylation sites. We achieved the quantitatively methylation detection in 13mer oligonucleotides without depending on the position of the methylation sites. We also achieved excellent discrimination of single cytosine methylation in 24mer oligonucleotides by the subtraction of the two voltammograms. These results indicate that this method can provide DNA methylation detection for a particular sequence with high stability and quantitatively. As a result, we successfully used ECR nanocarbon film to develop a simple electrochemical DNA methylation analysis technique without any bisulfate or labeling processes.

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DNAシーケンサ開発の歴史と最近の進歩

日立中研

○神原　秀記

DEVELOPMENT AND PROSPECT OF DNA ANALYZER

Hideki Kambara

Centarl Research Laboratory, Hitachi Ltd., Kokubunji-shi, Tokyo 185-8601

These ten years, life science and biotechnology fields have been progressed greatly. It has been promoted by Human Genome Project based on DNA analysis. The DNA sequencing by autoradiography was labor intensive and time consuming. Wada project firstly tried to automate the sequencing processes. Automated fluorescent DNA sequencers developed by several groups were commercialized in late 1980’s, which encouraged people to start the Human Genome Project in 1990. The Human Genome Project completed in 2003 by using capillary array DNA sequencers which indicated the importance of massive analyses of bio-molecules. More recently, various massive parallel DNA sequencers based on step-by-step nucleotide incorporation reactions have been developed. The sequencing throughput is more than two orders of magnitude higher than that of a capillary array DNA sequencer.

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くし形電極のナノスケール化による高感度化の検討

NTTマイクロシステムインテグレーション研究所

○林 勝義、高橋淳一、堀内 勉、岩崎 弦、芳賀恒之

STUDY ON NANO-SCALE INTERDIGITED ARRAY ELECTRODE FOR HIGHLY SENSITIVE DETECTION OF BIOMOLECULES

Katsuyoshi HAYASHI, Jun-ichi TAKAHASHI, Tsutomu HORIUCHI, Yuzuru IWASAKI, Tsuneyuki HAGA

NTT Microsystem Integration Laboratories,Atsugi-shi, Kanagawa 243-0198

We studied nanoscale interdigitated array electrodes (nano-IDAEs) to create a detector platform for highly sensitivity biosensing devices. We successfully fabricated a gold nano-IDAE with 1000 pairs of electrode (width and gap both 250 nm) and a 1 mm band length. We also fabricated a series of IDAEs whose widths and gaps ranged from 250 nm to 2 μm, and performed cyclic voltammetry with the IDAEs using 100 μＭ of ferrocenylmethyl trimethyl ammonium bromide solution to evaluate their characteristics. As the width and gap (line and space) of the IDAEs decreased, the difference between the experimental and theoretical limiting currents became larger, and when the line and space were 250 nm, the limiting currents were about 20% higher than the theoretical value. We also employed the nano-IDAEs for measuring adrenaline. We demonstrated that the collection efficiency of 0 % obtained when using a 2 μm IDAE could be improved to more than 60 % when using a 250 nm.

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生体高分子を電気化学的に固定化するEC tagとその分子-接点の解析

九工大院生命体

○坂元博昭、長武史、松山省太郎、池野慎也、春山哲也

THE EC TAG FOR ELECTROCHEMICAL IMMOBILIZATION OF
BIOMACROMOLECULES AND ALALYSIS OF THE JUNCTURE BETWEEN
MOLECULE AND SOLID SURFACE

Hiroaki SAKAMOTO, Takeshi CHO, Sho-taro MATSUYAMA, Shinya IKENO, and Tetsuya HARUYAMA

Department of Biological Functions and Engineering, Kyushu Institute of
Technology, Kitakyushu Science and Research Park, Fukuoka 808-0196, Japan

Molecular immobilization is a way to making molecular devices, e. g. biosensor, biochip, bio-batteries. To fabricate the functional interface, it is essential to preserve the function of the molecule and the structure of molecular layer. We have developed a novel method of molecular immobilization through electrochemical reaction. The method is based on a novel finding about an interfacial phenomenon that coordinates the metal ion in the peptidic ligand which can be reduced and deposited on an electrode while preserving the bond between metal and ligand¹⁾. In this study, using the EC tag tagged molecule, electrochemical molecular immobilization was performed and an investigation of the molecule-solid juncture (the interface between molecular layer and solid surface) was undertaken which employed both chemical quantifications and X-ray photoelectron spectroscopy (XPS). All the experimental results indicated that at the molecule-solid juncture, the coordinated Cu²⁺ ion in the EC tag ligand was reduced electrochemically to a zero-valent metal state in deposited form on the electrode surface (conductive solid surface), while the complex preserved the bond between the deposited metal and the EC tag ligand.

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交流インピーダンス法による酵母の代謝物測定と薬効評価への応用

富山県工業技術センター^a、立山マシン（株）^b

○堀井雅恵^a、高田耕児^a、日出嶋宗一^b、横山義之^a、浅田峯夫^a、鍋澤浩文^a、藤城敏史^a、谷野克巳^a

MEASUREMENT OF YEAST METABOLITE USING IMPEDANCE METHOD AND THE APPLICATION TO DRUG ASSESSMENT

Masae HORII ^a, Koji TAKATA ^a, Soichi HIDESHIMA ^b, Yoshiyuki YOKOYAMA ^a, Mineo ASADA ^a, Hirofumi NABESAWA ^a, Satoshi FUJIKI ^a, Katsumi TANINO ^a

^aToyama Industrial Technology Center, 383 Takada, Toyama-shi, Toyama 930-0866
^bTateyama Machine Co. Ltd., 30 Shimonoban, Toyama-shi, Toyama 930-1305

The purpose of this study is to develop the electrochemical device for convenient and rapid method to analyze proliferation and metabolic state of planktonic cells using easily-handled budding yeast. Charge transfer resistance (Rct) and resistance of solution (Rs) were measured on yeast culture broth by impedance method using suitable electrode and solution for each measurement. As　yeast proliferated, Rct increased due to adsorption of some metabolic proteins to the electrode and Rs decreased due to increase of ionic metabolite. Based on the results, Rct and Rs were measured on the yeast culture medium that included various concentration of extracted essence from several natural medicines to examine their effect to yeast proliferation. Measurements of both Rct and Rs showed that extracts of Coptis japonica var. major inhibited yeast proliferation. Impedance sensing can be useful for planktonic live cell-based drug assessment.

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生体成分計測用バイオFETの研究開発（Ⅱ）硝酸ISFETの膜材料の検討

産総研健康工学RC^a、阪工大工^b

○脇田 慎一^a、吉田 尚弘^b、森 智久^b、澁谷 康彦^b

R & D OF BIOFET FOR BIOLOGICAL MONITORING（Ⅱ） STUDY ON MEMBRANE MATERIALS FOR NITRATE ISFETs

Shin-ichi WAKIDA ^a, Naohiro YOSHIDA ^b, Tomohisa MORI ^b and Yasuhiko SHIBUTANI <sup>b

a</sup>Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST),
Midorigaoka 1-8-31, Ikeda, Osaka 563-8577
^bFaculty of Engineering, Osaka Institute of Technology, Omiya 5-16-1, Asahi, Osaka, Osaka 535-8585, Japan

To develop high performance nitrate ion-selective field-effect transistors (ISFETs) to detect a human salivary nitrate, we investigated polymer membrane materials, such as poly(vinyl chloride) (PVC), poly(vinyl chloride) calboxylated (PVC-COOH) and poly (urethane-urea) (KP-13) for highly sensitive, selective and stable NO₃^--ISFETs using the suitable copper(I) complex ([Cu(bcp)₂]NO₃) as a nitrate-sensing material, 2-nitrophenyl- dodecylether (NPDDE) as a liquid membrane material (plasticizer). We studied the membrane-material effect for static sensor characteristics of NO₃^--ISEs, such as linear response range, slope sensitivity, selectivity and durability. The NO₃^- ion-selective electrodes (ISEs) based on PVC, PVC-COOH and KP-13 showed almost the same sensor characteristics. We also prepared prototype of FET NO₃^- checker using the above-mentioned membrane materials. We applied human saliva after pretreatment using a cartridge column packed with cation-exchange resin of the silver form using direct potentiometry. In any case, we obtained relatively good correlation with conventional ion chromatography.

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過酸化水素放出を指標とする白血球細胞バイオセンサの開発

東北大院環境^a，東北工大院環境情報工^b，兵庫県立大院物質理^c

○井上（安田）久美^a、伊野 浩介^a、珠玖 仁^a、葛西 重信^b、安川 智之^c、水谷 文雄^c、末永 智一^a

CELL-BASED BIOSENSOR FOR DETECTING TOXIC ACTIVITIES USING LEUCOCYTES

Kumi Y. INOUE ^a, Kosuke INO ^a, Hitoshi SHIKU ^a, Shigenobu KASAI ^b, Tomoyuki YASUKAWA ^c, Fumio MIZUTANI ^c and Tomokazu MATSUE ^a

^a Graduate School of Environmental Studies, Tohoku University, 6-6-11 Aoba, Aramaki,　Aoba, Sendai 980-8579
^b Department of Environmental Information Engineering, Tohoku Institute Technology, 35-11 Kasumicho, Taihaku, Sendai 982-8588
^c Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297

We have developed a biosensor to detect the hazardous contaminants in medical supplies and environmental samples. Aiming at rapid detection, we employed the leucocytes as sensing elements, which can produce hydrogen peroxide on exposure to toxicants and pathogens. At first, the ability of leucocytes to produce hydrogen peroxide was estimated by the luminal chemiluminescence method. Peripheral blood leucocytes produced hydrogen peroxidase on exposure to 500 ng/ml lipopolysaccharide (LPS), 1 ng/ml phorbol 12-myristate 13-acetate (PMA) and E. coli within 1 hr. On the other hand, the leukemia cell line HL-60, THP-1, retinoic-acid-differentiated HL-60 and PMA-differentiated THP-1 were less sensitive or did not produce detectable amount of hydrogen peroxide by the same stimulants. Then, the electrochemical detection was examined. The increase of the oxidation current on Pt microelectrode at +0.7 V vs Ag/AgCl set near the peripheral blood moncytes was observed on stimulation by 1,800 ng/ml PMA. We are now trying to use the osmium wired peroxidase polymer for higher sensitive hydrogen peroxide detection. The ITO electrode and Au disc electrode coated with the osmium wired peroxidase polymer could sense more than 100 times lower concentration of hydrogen peroxide than bear Pt electrode in PBS.

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高密度単一細胞アレイを用いた希少細胞検出技術の開発

東京農工大院生命

○細川 正人、新垣 篤史、竹山 春子、松永 是

DEVELOPMENT OF RARE CELL DETECTION TECHNIQUE USING A HIGH-DENSITY CELL ARRAY

Masahito HOSOKAWA, Atsushi ARAKAKI, Haruko TAKEYAMA and Tadashi MATSUNAGA

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

Detection and isolation of rare cells from limited biological samples have become major challenges in clinical diagnosis and research in the field of cell biology. Thus, a simple yet efficient method that enables both rapid enumeration and assured isolation of target cells in single-cell resolution is warranted. In this study, in order to enable rare cell detection at the single-cell level from a small quantity of sample, we developed a microfluidic device equipped with a high-density microcavity array. Using this device, several thousands of individual cells were trapped onto the array with high efficiency (approximately 90% of loaded cells). Cell-specific immunophenotypes were identified at the single-cell level by measuring fluorescence intensities of cells reacted with antibodies targeting cell surface markers. The purity of hematopoietic stem cells (HSCs) within human peripheral blood analyzed by this system was correlated with the result obtained by traditional flow cytometry. In addition, gene expression of stem cell marker CD34 was determined from single HSCs by isolating cells using a micromanipulator.

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癌細胞の蛍光・磁気標識のための量子ドット-磁性細菌粒子ナノ複合体の構築

東京農工院生命^a、プレシジョン システム サイエンス^b

○前田 義昌^a、吉野 知子^a、高橋 正明^b、銀屋 治巳^b、朝比奈 潤子^b、田島 秀二^b、松永 是^a

NOVEL NANOCOMPOSITES CONSISTING OF QUANTUM DOTS AND
BACTERIAL MAGNETIC PARTICLESFOR FLORESCENCT AND MAGNETIC LABELING OF CANCER CELLS

Yoshiaki MAEDA ^a, Tomoko YOSHINO ^a, Masaaki TAKAHASHI ^b, Harumi GINYA ^b,
Junko ASAHINA ^b, Hideji TAJIMA ^b and Tadashi MATSUNAGA ^a

^a Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588
^b Precision System Science Co., Ltd., Matsudo, Chiba, 271-0064

Novel nanocomposites consisting of nano-sized bacterial magnetic particles (BacMPs) and semiconductor quantum dots (QD) were developed for use in targeting and identifying cancer cells. BacMPs are synthesized by magnetotactic bacterium, Magnetospirillum magneticum AMB-1 and can display functional proteins using gene fusion techniques. In this study, two functional proteins, biotin carboxyl carrier protein (BCCP), derived from AMB-1 and protein G, derived from Streptococcus were displayed on BacMPs. BCCP was biotinylated in AMB-1 cells by endogenous biotin ligase. After purification of in vivo-biotinylated BacMPs, streptavidin and antibodies were immobilized on protein G-BCCP-displaying BacMPs (protein G-BCCP-BacMPs) via biotin and protein G, respectively. Furthermore, multi-color labeling of the protein G-BCCP-BacMPs was achieved with streptavidin-labeled QD. Using streptavidin-QD/protein G-BCCP-BacMP nanocomposites, we successfully demonstrated magnetic manipulation and fluore

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酵素電極反応を利用したグルタミン酸の電気化学検出

東京理科大理^a、群馬大工^b

○池田　昌隆^a、駒場　慎一^a、白石　壮志^b

FABRICATION OF A GLUTAMATE BIOSENSOR BASED ON ENZYME IMMOBILIZED ELECTRODE

Masataka IKEDA ^a, Shinichi KOMABA ^a, Soshi SHIRAISHI <sup>b

a</sup> Department of Applied Chemistry, Tokyo University of Science, Shinjuku, Tokyo 162-8601
^b Department of Chemistry and Chemical Biology, Graduate School of Engineering,
Gunma University, Kiryu-shi, Gunma 376-8515

An enzyme immobilized electrode was fabricated for the application of glutamate sensors; glutamate dehydrogenase (GLDH) as an electrode catalyst, meldola blue (MelB) as a mediator, carbon nanotube (CNT) giving the electron transfer network within the electrode, and polyion complexes (PIC) as immobilized matrix for the electrode. PIC was consisted of poly-L-lysine and poly(sodium 4-styrenesulfonate). We evaluated the electrochemical properties of the fabricated electrodes. The CNT/MelB/GLDH/PIC electrode exhibited amperometric response to glutamate concentration in the range up to 1 mM. In particular, current density was linearly increased with glutamate concentration from 1 to 100 μM. The electrode was expected to be applied as biosensors for glutamate by utilizing these linear relation.

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ピルビン酸デヒドロゲナーゼを用いたピルビン酸センサの電気化学インピーダンス法を用いた評価

東理大理工

○石塚由樹、四反田功、板垣昌幸、渡辺邦洋

Impedance Measurement for Amperometric Pyruvate Sensor Based on Pyruvate Dehydrogenase

Yuki ISHIDUKA, Isao SHITANDA*, Masayuki ITAGAKI and Kunihiro WATANABE

Impedance Measurement for Amperometric Pyruvate Sensor Based on Pyruvate Dehydrogenase
Faculty of Science and Technology, Tokyo University of Science Noda, Chiba 278-8510

Amperometric pyruvate biosensor was fabricated using a screen printed carbon electrode. Pyruvate dehydrogenase (PDH) and 2-methyl-1,4-naphtoquinone were used as enzyme and mediator, respectively. An aliquot of PDH solution and 2-Methyl-1,4-naphtoquinone was dropped onto the carbon electrode surface, followed by dropping 1 % nitrocellurose solution. The enzyme electrode was immersed in 0.1 M phosphate buffer (pH 6.25) containing 10 mM MgSO₄, 0.2 mM thiamine pyrophosphate (TPP) and 10μM FAD prior to use. The electrochemical impedance measurements of the PDH-modified electrode were performed by three electrode method in a phosphate buffer solution (pH 6.25). A small capasitive loop related to the ion permiation resistance of the membrane was observed in high frequency region. In middle frequency region, a capacitive loop was shown on the Nyquist plane, and the diameter of the capacitive loop corresponds to the pyruvate concentration. We simulated the impedance spectra by using an equivalent circuit model.

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