Vol. 22, Supplement A (2006)

Abstracts

A Novel Electrical Conductivity Simulation Approach
on the SnO₂ Based Solid State Gas Sensor Material

○ Ｚhigang ZHU^a, Chutia ARUNABHIRAM^a, TSUBOI^a, Michihisa KOYAMA^a,
Akira ENDOU^a, Momoji KUBO^a, Carlos A. DEL CARPIO^a, Akira MIYAMOTO^a,b

aDepartment of Applied Chemistry, Tohoku University, Sendai 980-8579
^bNew Industry Creation Hatchery, Tohoku University, Sendai 980-8579

A theoretical method based on our original tight-binging quantum chemical method was used to investigate the electrical and electronic properties of SnO₂, which typify one of the most frequently used semiconductor material for gas-sensing applications. The calculated electronic structures for defect-free bulk and (110) surface of SnO₂ were in good agreement with experimental results and previous first-principles calculations. The effect of oxygen deficiently on the electrical properties of the (110) surface was investigated. It was found that the calculated electrical conductivities are enhanced significantly due to the formation of defect level in the forbidden band. We also aim to discuss the effect of gaseous molecules such water and oxygen on the electrical conductivity of tin dioxide surface.

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SnO₂クラスター分散水溶液を用いた高感度薄膜型ガスセンサの検討

九大院総理工

吉田宏平、○湯浅雅賀、島ノ江憲剛、山添�f

DESIGN OF HIGHLY SENSITIVE THIN-FILM-TYPE GAS SENSOR USING TIN OXIDE CLUSTER

Kouhei YOSHIDA^*, Masayoshi YUASA^**, Kengo, SHIMANOE^**, Noboru Yamazoe^**

^* Interdisciplinary Graduate School of Engineering Sciences, Kyushu
University, Kasuga, Fukuoka 816-8580, Japan
^** Faculty of Engineering Sciences, Kyushu University, Kasuga, Fukuoka
816-8580, Japan

For highly sensitive thin-film-type gas sensor based on the control of high order structure, the stable colloidal suspensions of SnO₂-cluster were investigated by subjecting conventionally SnO₂ gels to hydrothermal treatment with an ammonia solution pH-controlled in the range of 8.0 to 10.5 under the pressure of 10 MPa at 200 ℃ for 3 h. Based on LPA analyses, the mean cluster sizes increased with the decrease in pH of the solution before the hydrothermal treatment. Thin films spin-coated from their suspensions were deposited on alumina substrates. The thin film prepared from SnO₂-clustered suspension proved high gas sensitivity to 200 ppm CO and H₂, as compared with the thin film prepared from mono-dispersed sol. From the results of TEM observation and pore-size distribution measurement, it is found that the particle size of clusters corresponded to the results of LPA analyses, and that the cluster particles developed meso-pore structure, respectively.

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3.

超音波噴霧熱分解法による多孔質酸化スズ
粉末の調製と半導体ガスセンサへの応用

長大工

稗田耕士，○兵頭健生，清水康博，江頭　誠

PREPARATION OF POROUS TIN DIOXIDE POWDERS BY PYROLYSIS
OF ATMIZED PRECURSOR SOLUTIONS
AND THEIR APPLICATION TO SEMICONDUCTOR GAS SENSORS

Koji HIEDA, Takeo HYODO, Yasuhiro SHIMIZU and Makoto EGASHIRA

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

Porous SnO₂ powders were prepared by pyrolysis of atomized precursor aqueous solutions (SnCl₂ or SnCl₄) containing polymethylmethacrylate (PMMA) microspheres as a template. Spherical macropores (150-200 nm in diameter) and the morphology reflecting the PMMA template could be formed in the SnO₂ powders (400-800 nm in diameter). The skeleton and shell of the porous SnO₂ microspheres prepared from a SnCl₂ solution were relatively thinner than those of one prepared from a SnCl4 solution. Among all the sensors tested, a SnO₂ sensor fabricated from the powder prepared by pyrolysis of a SnCl₂ aqueous solution at 1100℃ showed the largest response to 1000 ppm H₂ in air.

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酸化スズ薄膜マイクロセンサの硫化水素ガス検知特性に及ぼすマイクロギャップの効果

立命館大理工

○中田谷昌徳、新美　潤、小西　聡、玉置　純

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

Yoshinori NAKATAYA, Jun NIIMI, Satoshi KONISHI^*, Jun TAMAKI

Department of Applied Chemistry, Faculty of Science and Engineering,
Ritsumeikan University, Kusatsu-shi, Shiga 525-8577, Japan
^*Department of Micro System Technology, Faculty of Science and Engineering,
Ritsumeikan University, Kusatsu-shi, Shiga 525-8577, Japan

The effect of microgap electrode has been investigated on dilute H₂S sensing properties of SnO₂ thin film microsensors.
The microgap electrode was fabricated by means of MEMS techniques (photolithography and FIB) and the gap size was varied in the range of 0.1-1 μm. The sensitivity to dilut e H₂S was slightly increased with decreasing gap size, suggesting the small microgap effect in SnO₂-H₂S system. The sensitivity was divided into the sensitivity at electrode-oxide interface (Si) and at oxide grain boundary (Sgb). Although Si was larger than Sgb in whole concentration range of H₂S, their ratio (Sgb/Si) was smaller than the previous results of WO₃-NO₂ system and In₂O₃-Cl₂ system. It was found that the small Sgb/Si ratio was responsible for the small microgap effect and that the large Sgb value was characteristic in SnO₂-H₂S system.

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カーボンナノチューブセンサのガス検知特性

（新コスモス電機^a、大阪大学^b）　

○伊藤達也^a、本多信一^b、片山光浩^b、尾浦憲治郎^b

Characterization of carbon nanotube (CNT) sensor
by catalytic chemical vapor deposition (CCVD) method

Tatsuya Itoa, Shin-ich Hondb, Mitsuhiro Katayama^b, ^*Kenjiro Oura<sup>b

a</sup>New Cosmos Electric Co., Ltd., 3-6-25 Mitsuya-naka, Yodogawa-ku, Osaka
^bDepartment of Electronic Engineering, Graduate School of Engineering,
Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0872 Japan

Carbon nanotube (CNT) film deposited by catalytic chemical vapor deposition (CCVD) was investigated as gas sensor.
The structure of CNT on an Al₂O₃ substrate was observed by SEM and Raman spectroscopies.
The diameter distribution of CNT was estimated by Radical Breathing Mode (RBM) in Raman spectra.
The sensor showed a decreasing of resistance on exposure to NO₂ and Cl₂ gases.
The gases were detected to the ppb level under room temperature operation.
The correlation between gas sensitivity and gas concentration was derived based on the Langmuir’s adsorption isotherm, predicting a detection limit of 8 ppb for NO₂.

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吸着燃焼を利用した高感度TVOCセンサの開発

矢崎総業，^*長崎大工

○笹原隆彦，加藤博照，齋藤亜矢子，西村昌晃，江頭　誠^*

DEVELOPMENT OF A HIGHLY SENSITIVE MICRO GAS SENSOR BASED
ON ADSORPTION AND COMBUSTION FOR TOTAL VOLATILE ORGANIC COMPOUNDS

Takahiko SASAHARA, Hiroteru KATO, Ayako SAITO, Masateru NISHIMURA, Makoto EGASHIRA^*

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

An adsorption/combustion type gas sensor with low heat capacity employing Pd/g-Al₂O₃ was fabricated on a silicon substrate by MEMS technology. The sensor was driven by low-high pulse heating at two temperatures of 200 and 400 degrees C. The sensor showed a large response peak to toluene upon high temperature combustion for 0.4 s after low temperature adsorption for 17.6 s. The peak response detected any toluene concentration in the range of 10-1000 ppb. The detection and the determination limit calculated from standard deviation of background noise in air were 8 ppb and 20 ppb, respectively. On indoor field tests of new residential houses using the adsorption/combustion type sensor, the total volatile organic compounds concentration by the sensor agreed with that obtained by GC/MS or GC/FID analysis using active carbon trapping.

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複数ガスセンサによる火災源種と位置の同定

金沢星稜大¹、金沢工業大学²、九州大学³

新保達也¹,○石榑大介²,東野　翼¹，沢田　史子¹，大薮多可志¹，南戸秀仁²，都甲　潔³

Identification of fire source and its location using plural tin oxide gas sensor

Tatsuya Shimbo¹, Daisuke Ishigure², Tsubasa　Higashino¹,Ayako Sawada¹,
Takashi Oyabu¹, Hidehito Nanto², Kiyoshi Toko³

Kanazawa Seiryo University ¹,gosho usi10-1,Kanazawa city,Ishikawa Prefecture,japan,
Knazawa Institute of Tech ²,7-1 Ohgigaoka Nonoichi Ishikawa,Japan,
Kyushu University ³,6-10-1,hakozaki,higasi-ku,fukuoka,japan

It was attempted to detect a smoldering fire which was caused by a cigarette. Same types of eight sensors are adopted in this experiment. The sensor is a type of a tin oxide gas sensor which is used to detect various kinds of reducing gases. It is on a market as a gas alarm detector. The sensor is mounted at a supporting bar and its height can be changed. The height was set at 50, 100 and 150 cm. The lighted cigarette was put on a cotton cloth and the generated gases were detected. The sensor output near the fire source fluctuates largely. It is attempted to identify the position, burning materials and propagation speed of the fire.
The sensor output was summed for every 2 seconds and the differential characteristic of the summed value was derived.
The characteristic is effective to identify the fire position. As for the result, it can be distinguished the fire position within about 30 seconds. Tin oxide gas sensor is good for detecting a smoldering fire.

 

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保安分野における化学ガスセンサの役割

新コスモス電機株式会社

重盛徹志

Roles of chemical gas sensors in the filed of safety

Tesshi SHIGEMORI

New Cosmos Electric Co., Ltd.
2-5-4 Mitsuya-naka,Yodogawa-ku,Osaka 532-0036,Japan

Gas safety products such as gas detectors/alarms equipped with combustible gas sensors, toxic gas sensors, or oxygen sensors, are one of the most important applications in the field of gas sensors. The purpose of gas detector/alarm units is to protect people and property from gas-related accidents. Because of this, the units must perform with the utmost reliability to accurately detect gases in virtually any environment. A number of gas sensors have been commercialized to date as residential gas alarms and industrial gas alarm systems, and they have contributed significantly to preventing accidents. Industrial advancements, however, have fueled market demand for products that offer even higher performance. On the one hand, there are a lot of possibilities to find new market with the advance of sensor technology.

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8.

アミド基を有する高分子検知膜を塗布した水晶振動子によるHClガス検知

愛媛大院理工

○松口正信、門脇良人

A QCM-BASED HCl GAS SENSOR COATED WITH POLY(ACRYLAMIDE) DERIVATIVES

Masanobu MATSUGUCHI, Yoshito KADOWAKI

Department of Applied Chemistry, Ehime University, Matsuyama 790-8577, Japan

A quartz resonator coated with 6 kinds of poly(acrylamide) derivatives were studied for simply but accurately detecting HCl gas in air. The exposure of the resonator to HCl gas reversibly decreased the oscillation frequencies. The sensitivity, response time, and reversibility were depended on the structure of amide group. Among the polymers used, poly(N,N-dimethylacrylamide)(PDMAA) showed the most relevant data for the HCl sensor. The HCl sensitivity obtained for PDMAA was ca. 0.17 ppm/Hz. On the other hand, the irreversible response towrd NO₂ gas was considerably high and great interference was also produced by changes in the test gas humidity.

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半導体酸化物を用いたテトラクロロエチレンセンサの開発

立命館大理工、フィガロ技研^*、ユニチカ環境技術センター^**

○谷平龍也、河口智博^*、宇高利浩^*、木村圭助^**、廣田一雄^**、玉置　純

DEVELOPMENT OF TETRACHLOROETHYLENE SENSOR USING SEMICONDUCTOR OXIDE

Tatsuya TANIHIRA, Tomohiro KAWAGUCHI^*, Toshihiro UDAKA^*, Keisuke KIMURA^**,
Kazuo HIROTA^**, Jun TAMAKI

Department of Applied Chemistry, Faculty of Science and Engineering,
Ritsumeikan University, Kusatsu-shi, Shiga 525-8577, Japan
^*R&D Department, Figaro Engineering Inc., Mino, Osaka 562-8505, Japan
^**Unitika Environmental Technical Center Ltd., Uji, Kyoto 611-8555, Japan

Semiconductor gas sensors to detect tetrachloroethylene (C₂Cl₄) have been investigated by using SnO2, In₂O₃, and WO₃ for the development of portable soil gas detection system. The decomposition of C₂Cl₄ was examined on these oxide based catalysts. The Fe₂O₃-oxides, Pd-SnO₂, and Pt-SnO₂ showed the high activity in C₂Cl₄ decomposition. The acid properties of catalysts were related with the decomposition activity and the acid site with moderate strength was effective to decomposition of C₂Cl₄. However, the sensors fabricated with Fe₂O₃-oxides hardly responded to C₂Cl₄, suggesting that the decomposition intermediates such as C fragments and Cl fragments offset the resistance change of sensor. On the other hand, Pd-SnO₂ sensor showed moderately high sensitivity to C₂Cl₄ at 300-350 ℃. The adsorption o f Cl was suppressed on Pd-SnO₂, inducing the large contribution of C fragments and thus the large resistance decrease of sensor.

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愛媛大工

○森　雅美、　細谷　祐樹、　板垣　吉晃、　青野　宏通、　定岡　芳彦

SENSING PERFORMANCES OF SmFe_1-xCo_xO₃ SEMICONDUCTIVE GAS SENSOR
TO LOW OZONE CONCENTRATION

Masami MORI, Yuuki HOSOYA, Yoshiteru ITAGAKI,
Hiromichi AONO and Yoshihiko SADAOKA

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

We are researching the gas sensors application of perovskite-type oxides prepared by thermal decomposition of heteronuclear complexes. A high sensitivity was obtained for SmFeO₃(x=0) even for sub-ppm level of ozone gas. However, the sensor had to be operated at high temperature because its conductivity was relatively low. In this study, the conductivity was controlled by substituting a part of Fe with Co, and sensing performances of SmFe_1-xCo_xO₃ p-type semiconductive gas sensors to low ozone concentrations were examined. The sensitivity of those sensors were measurable at low temperatures due to an increase of their conductivity. The specimen with x=0.1-1.0 showed a high sensitivity at 100℃ or less to low ozone concentrations. Furthermore, the influence of the contamination of several VOCs in monitoring environment was examined. The sensitivity to VOCs showed high value at high temperature. In other hand, at low temperature, the sensitivity to ozone was hardly influenced by VOCs-existence. The partial Co substitution was effective for the detection of ozone containing VOCs.

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YSZ表面へのリチウムイオン伝導層の形成とCO₂ガスセンサへの応用

愛媛大工

◯政吉 健志、板垣 吉晃、青野 宏通、定岡 芳彦

FORMATION OF LITHIUM ION CONDUCTION LAYAR ON SURFACE OF YSZ AND ITS
APPLICATION FOR POTENTIOMETRIC CO₂ GAS SENSOR.

Takeshi MASAYOSHI, Yoshiteru ITAGAKI, Hiromichi AONO and Yoshihiko SADAOKA

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

Li₂CO₃ and ZrO₂ mixture on YSZ sheet was calcined to prepare Li⁺ conducting layer. Single phase Li₂ZrO₃ layer (ca.10μm) having high density was obtained on the surface of YSZ when Li₂CO₃ and ZrO₂ mixture (1:0.1 in mol ratio) was calcined at 950℃ for 2h. The conductivity of the YSZ with the Li⁺ conducting layer was almost the same value with that of the YSZ sheet. The CO₂ gas sensor using the YSZ sheet having Li⁺ conducting layer showed the stable EMF response at 300℃. However, the EMF was drifted at 35℃and 400℃, because the Li₂ZrO₃ phase would react with Li₂CO₃ auxiliary phase.

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複合亜硝酸塩補助相によるNASICONベース低温作動型NO₂センサの水蒸気妨害の改善

北九州高専

小畑賢次, 松嶋茂憲

REDUCTION OF THE INTERFERENCE OF WATER VAPOR IN NASICON-BASED NO₂ SENSOR ATTACHED
WITH METAL OXIDE AND NITRITE COMPOUND OPERATIVE AT LOW TEMPERATURE

Kenji OBATA and Shigenori MATSUSHIMA

Department of Materials Science and Chemical Engineering, Kitakyushu National College of Technology, 5-20-1 Shii, Kokuraminami-ku, Kitakyushu-shi, Fukuoka 802-0985

NASICON (Na₃Zr₂Si₂PO₁₂)-based potentiometric NO₂ devices were fabricated by combining ITO powders with NaNO₂, NaNO₂-Li₂CO₃ (9:1 in molar ratio) or NaNO₂-Li₂CO₃-BaCO₃ (9:1:2 in molar ratio) as an auxiliary phase. Their NO₂ sensing properties were investigated in the range of 1.9 to 6.7 ppm NO₂ under 1 - 50%RH between 30 and 150℃. The NO₂ sensitivity of (ITO, NaNO₂)-attached device was fluctuated by the change of the humidity condition. In addition, the EMF values of the device in a fixed NO₂ concentration shifted up with increasing humidity at 30℃ On the other hand, the NO₂ sensing properties of (ITO, NaNO₂-Li₂CO₃)-attached and (ITO, NaNO₂-Li₂CO₃-BaCO₃)-attached devices were remarkably improved, compared with those of (ITO, NaNO₂)-attached one. These results suggest that the interference of water vapor to NO₂ sensing properties of the device is effectively reduced by using an auxiliary phase with resistance to deliquescence.

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混成電位型ジルコニアセンサにおける
NO2感度の酸化物検知極膜厚への依存性

九州大学¹、リケン(株)²

◯ペルマル　エルマレイ¹，ブラディミル プラシニツァ¹, 上田 太郎¹，長谷井　政治²，
三浦　則雄³

DEPENDENCE OF NO2 SENSITIVITY ON THICKNESS OF
OXIDE SENSING-ELECTRODE FOR MIXED-POTENTIAL-TYPE ZIRCONIA SENSOR

◯Perumal ELUMALAI¹, Vladimir V. PLACHNITSA¹, Taro UEDA¹, Masaharu HASEI², Norio MIURA1

¹ Art, Science and Technology Center for Cooperative Research,
Kyushu University, Kasuga-shi, Fukuoka 816-8580, Japan
² R&D Division, Riken Corporation, Kumagaya-shi, Saitama 360-8522, Japan

The effect of thickness of oxide sensing-electrode (SE) on NO₂ sensitivity of the planar sensor based on yttria-stabilized zirconia (YSZ) was examined at high temperatures. The sensitivity of the sensor increases with decreasing thickness of Cr₂O₃-SE (or NiO-SE) and the highest sensitivity was obtained by using the thinnest layer of Cr₂O₃-SE (~2.7 μm). In the case of NiO-SE, the highest sensitivity was observed for the sensor using the 4 μm-thick SE even at high temperature of 850℃. Based on the results of the measurements for the complex impedances, the polarization curves and the gas-phase NO₂ decomposition catalysis, it was confirmed that the catalytic activity to the gas-phase NO₂ decomposition on the oxide-SE matrix played an important role in determining the NO₂ sensitivity of the present sensors.

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WO₃を添加したNiO検知極を用いた混成電位型ジルコニアセンサのNO₂応答特性

(九大産学連携センター^a、リケン(株)^b )

○王 健^a, 寺田 大将^a, エルマレイ ペルマル^a, 上田 太郎a, 長谷井 政治^b, 三浦 則雄^a

SENSING CHARACTERISTICS OF MIXED-POTENTIAL-TYPE ZIRCONIA-BASED
NO₂ SENSOR USING WO₃-ADDED NiO SENSING-ELECTRODE

Jian WANG^a, Daisuke TERADA^a, Perumal ELUMALAI^a, Tarou UEDA^a, Masaharu HASEI^b, Norio MIURA^a

^a Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi,
Fukuoka 816-8580
^b R&D Division, Riken Corporation, Kumagaya-shi, Saitama 360-8522

We have lately reported that NiO sensing-electrode (SE) gives the highest NO₂ sensitivity at high temperature of 800-900℃ for a mixed-potential-type zirconia-based sensor. In addition, NO₂ sensitivity was found to be enhanced significantly by the addition of 3 wt.% Rh into NiO-SE. Since the use of expensive Rh is not favorable for actual application, we examined here various kinds of metal oxides as an alternative additive to NiO-SE. Among the oxides examined, WO₃ was found to give the largest improvement effect on NO₂ sensitivity and the maximum sensitivity was observed when the NiO-SE was formed by sintering at 1400℃ after the addition of 10 wt.% WO₃. At 800℃, the NO₂ sensitivity of the sensor using 10 wt.% WO₃-added NiO-SE was almost twice of that using pure NiO-SE and was nearly equal to that using 3 wt.% Rh-added NiO-SE. The reason for the improvement in NO₂ sensitivity by the addition of WO₃ was also examined and discussed.

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アルミニウムイオン伝導体を用いた新規なNO_xセンサ

阪大院工

○田村 真治，長谷川 功，今中 信人

NITROGEN OXIDES GAS SENSOR BASED ON
ALUMINUM ION CONDUCTING SOLID ELECTROLYTE

Shinji TAMURA, Isao HASEGAWA, Nobuhito IMANAKA

Department of Applied Chemistry, Faculty of Engineering Osaka Universit
2-1 Yamadaoka, Suita, Osaka 565-0871 Japan

A new type of nitrogen oxides gas sensor was fabricated by using aluminum cation conducting solid electrolyte with sensing auxiliary electrode and Al metal thin film loaded on each surface of the electrolyte disk. The present nitrogen oxides gas sensor showed such good sensing performances of rapid, stable, continuous, and reproducible response and a linear relationship between the sensor output and the logarithm of the NO concentration was obtained in the gas concentration range from 200 to 2000 ppm at 250°C. The sensor output variation with the NO gas concentration change was in an excellent agreement with the theoretical one for the sensor with the KNO₃ doped Gd₂O₃-Nd₂O₃ solid solution ((Gd_0.4Nd_0.6)₂O₃-KNO₃) as the sensing auxiliary electrode.

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小型水素ポンプ・ゲージの作製とその特性

（秋田大学工学資源学部）

○金児紘征、 川畑哲郎、 多田英司

PREPARATION AND PROPERTIES OF A MINIATURE HYDROGEN PUMP-GAUGE

Hiroyuki KANEKO, Tetsuro KAWABATA and Eiji TADA

Department of Materials Science and Engineering,
Akita University, 1-1 Tegata Gakuen-cho, Akita, 010-8502

A miniature CaZr_0.9ln_0.1O_3-α hydrogen pump-gauge with aperture was constructed and applied to measure hydrogen pressure. Hydrogen pressure was analyzed by Hetric etal.'s method ¹⁾ to avoid hydrogen leakage from internal chamber.
It was successfully measured within a few seconds at 600℃ in the range 10^-3- 0.07 atm. This device is useful for measuring a steady-state hydrogen pressure and also it can be applied to survey a fluctuated hydrogen pressure.

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酸化物レセプタを用いた固体電解質インピーダンス検出型NO_xセンサ

九工大工

○木庭大輔、荒木友里、高瀬聡子、清水陽一

SOLID ELECTROLYTE IMPEDANCEMETRIC NO_xSENSOR USING OXIDE RECEPTOR

Daisuke KOBA, Yuri ARAKI, Satoko TAKASE and Youichi SHIMIZU

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

The new type solid-electrolyte impedance metric NO_x sensor electrochemical device composed of Li_1.5Al_0.5Ti_1.5(PO₄)₃ (LATP) as the transducer and various oxide (n-type (TiO₂, SnO₂, WO₃), p- type (NiO, Cr₂O₃) semiconductor and perovskite-type oxide LaBO₃ (B= Co, Cr, Ni, Mn, Fe) ) as receptor, respectively, have been systematically investigated for the detection of NO_x (NO and NO₂) in the range 10-200ppm at 400-500℃. Responses of these sensors were able to divide component between resistance and capacitance, and it was found that the device is applicable to the selective detection of NO and NO₂ concentration in each ingredient. Respectively TiO₂, SnO₂ (n-type semiconductor) and perovskite-type oxide based receptor gave good response to NO and NO₂. We found different response between n-type and p-type semiconductor, tried to elucidate of sensing mechanism.

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アパタイト型構造を有するLi_xLn_10-xSi₆O_27-x (Ln=La,Nd,Sm)系固体電解質の
イオン伝導とCO₂ガスセンサへの応用

愛媛大工

○宮廣　匠、藤嶋　学、板垣吉晃、青野宏通、定岡芳彦

CONDUCTIVITY OF APATITE -TYPE Li_xLn_10-xSi₆O_27-x(Ln=La,Nd,Sm) AND ITS
APPLICATION FOR POTENTIOMETRIC CO₂ GAS SENSOR

Takumi MIYAHIRO, Manabu FUJISHIMA, Yoshiteru ITAGAKI, Hiromichi AONO,
and Yoshihiko SADAOKA

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

Apatite-type Li_xLn_10-xSi₆O_27-x (Ln=La,Nd,Sm) (x=0,1,2,3) electrolytes were prepared for the application of potentiometric CO₂ gas sensor. The x=2,and 3 samples were single phase and high density by sintered at 1300℃. Although the conductivity of x=2,and 3 was lower than that of x=0,1, then carrier ion estimated to be Li⁺ ion. The mixture of Li₂CO₃ and Li_xLn_10-xSi₆O_27-x was very stable at below 700℃. The EMF for the CO₂ gas sensor using Li₂Nd₈Si₆O₂₅ drifted in initial stage, and then the EMF showed stable value .

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安定化ジルコニアと酸化物検知極を用いた電流検出型センサの炭化水素検知特性

九大院総理工^a、 九大産学連携センター^b

○上田太郎^a、 中藤充伸^a、 三浦則雄^b

SENSING CHARACTERISTICS OF AMPEROMETRIC HYDROCARBON SENSORS
BASED ON STABILIZED ZIRCONIA AND OXIDE SENSING-ELECTRODE

Taro UEDA ^a, Mitsunobu NAKATOU ^a, 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

The sensing characteristics to C3H₆ were examined at 600℃ for the amperometric sensor using a yttria-stabilized zirconia (YSZ) tube and ZnO (+ 1.5 wt.% Pt) sensing electrode (SE). It was found that the current response varied almost linearly with C₃H₆ concentration in the range of 0 - 200 ppm under wet condition. When the potential of SE was fixed at +70 mV (vs. Pt/air reference
electrode; RE), the present sensor showed good gas selectivity to C₃H₆ as well as acceptable response speed. In order to increase the current response, the peak current was measured as a sensing signal under the condition where the potential of SE was polarized at +1.0 V (vs. RE) for a period of only 0.3 s in the flow of sample gas containing C₃H₆ at 600℃. The sensitivity based on the peak current to 200 ppm C₃H₆ was increased up to about 1000μA. The selectivity to C₃H₆ was confirmed to be also excellent in this case.

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電極触媒の酸化活性差を利用する電流検出型固体電解質
炭化水素センサ

九州大学大学院工学研究院

○石原達己，Atanu Dutta, Zhonghe Bi, 松本広重

Amperometric solid state hydrocarbon sensor based on the oxidation activity
of electrode

Tatsumi Ishihara, Atanu Dutta, Zonghi Bi, and Hiroshige Matsumoto

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

Amperometric hydrocarbon sensor using Fe doped LaGaO₃ based oxide was investigated and it was found that the selective detection can be achieved by using difference in oxidation activity of electrode. In this study, detection characteristics of Pt-Co-LDC/LSGF(7373)/La_0.5Sr_0.5MnO₃ was studied and furthermore, long term stability was also studied. In order to identify the electrode reaction, impedance analysis was also performed and it was found that the cathodic overpotential is much larger than that of anode. The developed sensor is highly selective to C₃H₆ and hardly dependent on O₂ concentration and also stable sensitivity was kept over 7 days.

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新規固体参照極を用いたプレナー型酸素センサの応答特性

九大院総理工^a、九大産学連携センター^b

中久保 昌平^a、寺田 大将^b、○和間 良太郎^a、三浦 則雄^b

SENSING CHARACTERISTICS OF PLANAR-TYPE OXYGEN SENSOR
USING NEW SOLID REFERENCE-ELECTRODE

Shohei NAKAKUBO^a, Daisuke TERADA^b, ○Ryotaro WAMA^a , Norio MIURA^b

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

The responses to oxygen of various Mn-based oxides were examined for searching a new solid reference-electrode material to use in a planar-type oxygen sensor based on YSZ. Among seventeen oxides tested, Mn₂O₃ was found to be most appropriate for the material. It was confirmed that Mn₂O₃ was insensitive not only to oxygen but also to any of various reducing gases that usually exist in automotive exhausts. When Mn₂O₃ was used as a reference electrode for the planar-type oxygen sensor attached with a Pt sensing-electrode, the sensor was confirmed to work well as an oxygen sensor in the concentration range from 0.1 to 20 vol.% at 600℃. This sensor could be also operated well as an A/F(λ) sensor in the examinedλrange from 0.87 to 1.06 at 600℃. The abrupt change in emf of about 700 mV was observed atλof around 1.0.

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完全埋込みを目指した組換え酵母を用いた酵素センサ

富山大学　工学部¹，国立感染症研究所²，�潟fンソー　基礎研究所³

山口　昌樹¹，○中野　敦行¹，谷山　忠義²，柳井　謙一³

A YEAST TRANSFORMANT-BASED ENZYME SENSOR FOR IMPLANTABLE APPLICATION

Masaki YAMAGUCHI¹, Atsunori NAKANO¹, Tadayoshi TANIYAMA² and Kenichi YANAI<sup>3

1</sup>Faculty of Engineering, University of Toyama, Toyama-shi, Toyama 930-8555
²National Institute of Infectious Diseases
³Research Laboratories, Denso Co.

We propose a new implantable enzyme sensor for blood glucose measurement using a transformant of glucose oxidase gene which requires no immobilization of enzyme and enables the reproduction of enzyme. It was revealed that the gox gene transformant reached in the logarithmic growth phase with an incubation period of 12 to 20 h. The enzyme activity generated by the transformant at 48 h (the stationary phase) and 240 - 600 h were 0.83 U/ml (OD660 = 21.8) and 1.62 U/ml (OD660 = 24.2), respectively. The detection current of the enzyme sensor was 0 - 1561 nA at a glucose concentration of 0 - 400 mg/dl. The relative standard deviation (RSD) was indicated a favorable result of 4.3 - 11.8%. Finally, an implantable enzyme sensor, based on the gox gene transformant, has been fabricated. The in vitro evaluation demonstrated the possibility of a biosensor, enabling the detection of concentrations of glucose of 0 - 400 mg/dl.

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凍結乾燥基質を用いた微小酵素活性測定システム

筑波大院数理物質^a、ヤマサ醤油^b

○森本 克也^a、サンジェイ・アパジャー^a、大上 直人^a、日下部 均^b、鈴木 博章^a

MICRO ANALYSYS SYSTEM FOR THE DETERMINATION OF
ENZYME ACTIVITIES USING FREEZE-DRIED SUBSTRATES

Katsuya MORIMOTO ^a, Sanjay UPADHYAY ^a, Naoto OHGAMI ^a, Hitoshi KUSAKABE^b, and Hiroaki SUZUKI <sup>a

a</sup> Graduate School of Pure and Applied Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305-8573b Yamasa Corporation, Choshi, Chiba 288-0056

A micro analysis system for the determination of enzyme activities was fabricated. The device consisted of a glass substrate with an L-glutamate sensor and a polydimethylsiloxane (PDMS) substrate with a flow channel. Enzyme substrates were freeze-dried and incorporated in a micro flow channel, which realized the analysis without any mixing procedures. The porous structure of the supporting layer and fine substrate particles facilitated permeation of a sample solution and rapid dissolution of the substrates. L-glutamate produced by the enzymatic reaction of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and g-glutamyl transpeptidase (g-GTP) was detected using the L-glutamate sensor. A significant improvement in sensitivity was observed compared with conventional approaches. The relation between the slope of the response curve and enzyme activities were linear up to 100 U/l for GOT, 100 U/l for GPT and 350 U/l for g-GTP.

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複数溶液の逐次導入・排出機構とそのバイオセンシングへの応用

筑波大院数理物質

梨子田典弘、○佐藤航、鈴木博章

MICROFLUIDIC DEVICE FOR SEQUENTIAL INJECTION AND FLUSHING OF SOLUTIONS
AND ITS APPLICATION TO BIOSENSING

Norihiro NASHIDA, Wataru SATOH, Hiroaki SUZUKI

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

A microfluidic system with injecting and flushing functions was developed. The system consisted of a glass substrate with driving electrodes and a polydimethylsiloxane (PDMS) substrate. Flow channels were formed with a dry-film photoresist layer. The hydrophilic flow channels facilitated the introduction of solutions from reservoirs. Injection and flushing of solutions were controlled by valves which operate based on electrowetting. The valves consisted of gold working electrodes formed in the channel or a through-hole formed in the glass substrate. Solutions were introduced from the reservoirs into a reaction chamber at the center of the chip and flushed through the valve formed in the through-hole. To demonstrate the applicability of the device to immunoassay, α-fetoprotein (AFP) was immobilized on a platinum electrode in the chamber using a plasma-polymerized film (PPF). After incubation with goat anti-AFP antibodies labeled with glucose oxidase (GOD), electrochemical detection was conducted and a distinct current increase was observed, which depended on the amount of immobilized AFP.

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ナノギャップ電極の創製とバイオセンサへの応用

阪府大　先端セ

椎木弘，○床波志保，岩本昌，長岡勉

FABRICATION OF NANO-GAP ELECTRODE AND ITS APPLICATION FOR BIOSENSING

Hiroshi Shiigi, Shiho Tokonami, Masashi Iwamoto, Tsutomu Nagaoka

Frontier Science Innovation Center, Osaka Prefecture University,
1-2 Gakuen-cho, Sakai 599-8570

We have presented a simple fabrication technique of nano-gapped Au particle film which is consisted of Au particle &#8211; alkylchain &#8211; Au particle repeated sequence.　The gap between particles was precisely controlled by alkylchain of dithiol used as a binder molecule. The controlled gap enables us to measure a very little resistance change caused by hybridization. Combining the film with an electrical property of DNA has been conducive to a great achievement for developing a rapid and sensitive DNA detection method without any PCR amplification, sophisticated instrumentation and fluorescent labeling with an easy handling electrical readout system.

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ＯＨＰシートを利用したナトリウムイオンセンサの作成と評価

（国立リハビリ研 ）

○外山滋

FABRICATION AND CHARACTERIZATION OF DODIUM ION SENSOR
BASED ON TRANSPARENCY FILM

Shigeru TOYAMA

Research Institute, National Rehabilitation Center for Persons with Disabilities 4-1
Namiki, Tokorozawa, Saitama 359-8855z

A sodium ion sensor based on a transparency film has been developed.
The basal electrode was layered by Cr, Au, Pt, Ag, and AgCl.
The electrode pattern was fabricated by using the Line Patterning Method.
The sensor gas an internal NaCl solution under the ion sensitive layer, which is introduced by replacing preformed polyethylene glycol layer under the ion sensitive layer with the NaCl solution through a pore.
The sensor exhibited stepwise response by adding NaCl solution during measurement.

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スクリーン印刷による３電極一体型チップの作成と、
ペプチドおよびアミノ酸の直接的電気化学測定

^a北陸先端大、^b石川産業創出支援機構、 ^c（有）バイオデバイステクノロジー

○近江　みゆき^a、井手上　公太郎^b、Kagan Kermana、牛島　ひろみ^c、高村　禅^a、民谷　栄一^a

0FABRICATION OF THE THREE-ELECTRODE SCREEN-PRNTED STRIPS,
AND VOLTAMMETRIC ANALYSIS OF AMINO ACIDS AND PEPTIDE

Miyuki CHIKAE^a, Koutarou IDEGAMI^b, Kagan KERMAN^a, Hiromi USHIJIMA^c, Yuzuru TAKAMURA^a, Eiichi TAMIYA^a

^aSchool of Materials Science, Japan Advanced Institute of Science and Technology,
1-1 Asahidai, Nomi City, Ishikawa 923-1292
^bIshikawa Sunrise Industries Creation Organization, 2-20 Kuratsuki, Kanazawa City, Ishikawa 920-8203
^cBiodevice Technology Ltd., 2-1 Asahidai, Nomi City, Ishikawa 923-1211

The label-free voltammetric detection of amino acids and peptide was performed using a disposable strips based on the screen-printed gold electrode (SPAuE) and carbon electrode (SPCE). The sensor was characterized by employing cyclic voltammetry (CV) in 0.5 M Na₂SO₄ containing 2 mM K₃[Fe(CN)₆]. T>he coefficients of variance both potential and current density of anodic potassium ferrocyanide signal were less of 2.0 % (n = 20), indicating the good performance and reproducibility of the screen-printing process. The screening of electroactivity in amino acids was performed by CV and differential pulse voltammetry (DPV). The oxidation signals of tryptophan (Trp), tyrosine (Tyr), methionine (Met), histidine (His), and cysteine (Cys), and the reduction signal of cystine could be observed among all the other of amino acids and cystine. Furthermore, we performed the voltammetric detection of a clinically important peptide, angiotensin II at a SPAuE. The oxidation signal of angiotensin II, containing a single Tyr residue, was monitored at a peak potential of 0.615 V (vs. Ag/AgCl) by DPV. Since the removal of the adsorbed amino acids and their oxidized products from the electrode surface has been a difficult task, the single-use SPAuE and SPCE are promising sensors for the electrochemical bioanalysis of proteins.

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三電極系の変則的使用によるオンチップpHスタットとその応用

筑波大院数理物質

○森本 克也、鈴木 博章

ON-CHIP pH-STAT BASED ON THE IRREGULAR USE OF
A THREE-ELECTRODE SYSTEM AND ITS APPLICATION

Katsuya MORIMOTO and Hiroaki SUZUKI

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

An on-chip pH-stat system was fabricated which operates based on the irregular use of a thin-film three-electrode system.
An iridium oxide pH-indicator electrode was used for the reference electrode, whereas a non-polarizable Ag/AgCl electrode was used for the working electrode. A potential change of the reference electrode caused a rapid current increase. Accompanying this change, the pH of the reaction chamber recovered to the initial value by the electrolysis of water on the auxiliary electrode. The device could be used for the titration of an acid or a base by measuring the charge, which could also be applied to the determination of urea by measuring the amount of protons accompanying the hydrolysis of urea. Linear relationships were observed between the generated charge and the concentration of the respective analytes.

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MEMS技術を利用したバイオチップの開発

早大理工

○逢坂　哲彌

DEVELOPMENT OF BIOCHIP USING MEMS TECHNOLOGY

Tetsuya OSAKA

School of Science and Engineering, Waseda University
3-4-1 Okubo,　Shinjuku, Tokyo 169-8555

Field effect transistors (FETs) modified with organosilane monolayers were fabricated for applying on-chip ion and biosensing. The devices showed a typical transistor property with a good stability in aqueous solutions. The amino monolayer-modified FET acted as an ion sensitive FET with a good pH sensitivity of 58 mV/pH, and the perfluoro-alkyl monolayer-modified FET worked as a reference device. These monolayer-modified devices were expected to be applied as an on-chip pH sensor. In addition, the device immobilized with enzyme enabled to detect trace concentration (10-9 to 10-6 M) of urea with a high sensitivity of 64 mV/decade. Moreover the detection of hybridization reaction of DNA was attempted. When DNA on the surface hybridized with complementary DNA, the gate voltage shifts due to the negative charge of DNA itself. The results showed that the gate voltage shifted by 53 mV in the case of using 20-mer DNA. Also, the voltage shifts depending on the number of mismatches in DNA were observed. Therefore the immobilized FET had a high capability for the detection of some biomaterials.

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酸化物系エレクトロクロミック薄膜素子よる環境イオンセンサ

九工大工

○竹安智宏、高瀬聡子、清水陽一

AN ENVIRONMENTAL ION SENSOR USING
ELECTROCHROMIC MULICOMPONENT THIN-FILM OXIDE

Tomohiro TAKEYASU, Satoko TAKASE, Youichi SHIMIZU

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

Electrochromic behavior of multicomponent metal oxide thin-film electrode and it's electrochemical characteristic have been studied for the use of environmental ion sensing devices. The metal oxide thin-films were prepared by spin-coating method on ITO-glass substrates from solutions including metal-octylates at 50℃. The transmittance variation of SnMn(9:1)Ox thin-film electrode at cyclic voltammetry showed dependence on nitrate ion concentration at -0.75V vs SCE. The transmittance at 460 nm of SnMn(9:1)Ox thin-film electrode exhibits dependence on nitrate ion concentration at -0.75V vs SCE, and not depend on hydrogen-phosphate ion and chloride ion concentration. The device seems to be an nitrate ion sensor with high selectivity and sensitivity.

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マイクロ流経路内のＬＡＰＳによる測定

（東北大工）

○ 吉信 達夫、伊藤 選、杵淵 達夫、松坂 篤志、加納 慎一郎

LAPS MEASUREMENT OF MICROCHANNELS

Tatsuo YOSHINOBU, Suguru ITO, Tatsuo Kinefuchi,
Atsushi MATSUIZAWA and Shin’ichiro KANOH

Department of Electronic Engineering, Tohoku University,
6-6-05 Aza-Aoba, Aramaki, Aboa-ku, Sendai 980-8579

The Light-Addressable Potentiometric Sensor (LAPS) is a semiconductor-based chemical sensor, in which the measuring location on the sensor surface can be addressed by illumination. By using a scanning laser beam, it can be used for visualization of the two-dimensional spatial distribution of ions in the solution in contact with the sensor surface.
In this study, we fabricated microchannels on the sensor surface using the SU-8 technology for possible application of the LAPS as a chemical sensing element in microfluidic devices such as μ-TAS and Lab-on-a-Chip.

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ルミノール電気化学発光と電極表面状態の関係

芝浦工業大学応用化学科

○吉見靖男，鎌田正行，山縣 優，関根真一

EFFECT OF SURFACE CONDITION ON ELECTROCHEMILUMINESCENCE OF LUMINOL

Yasuo YOSHIMI, Masayuki KAMADA, Yu YAMAGATA, Shinichi SEKINE

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

We have reported that electrode surface modification with polycation-polyanion adsorption blocks approach of anionic reducers (uric acid and ascorbic acid). However, the modification cannot prevent electrochemiluminescence (ECL) of luminol from inhibition by the anionic reducers. The authors speculated that the electrode-modification by polyions promoted ECL reaction in bulk of the solution rather than that at vicinity of the electrode surface. We designed a new method of masking luminescence generated in bulk solution using red-colored dye. Eosin yellowish and beet red was selected as the dyes because they have little interaction with anodic reaction of luminol or hydrogen peroxide. The dyes did not affect the intensity of ECL of luminol without hydrogen peroxide. However they decreased slightly the intensity of ECL of luminol with hydrogen peroxide (signal ECL). They decreased the intensity of the signal-ECL with polycation-polyanion adsorbed electrode more significantly. The masking method of the bulk-ECL by dye is feasible for basic study of ECL mechanism.

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SPR免疫センサによる爆発性化合物の高速高感度検出

九州大学^a、JSPSb

○D. ラビ シャンカラン^a,b, 松本 清^c, 都甲 潔^d, 三浦則雄^a

RAPID AND HIGHLY SENSITIVE SPR IMMUNOSENSOR FOR EXPLOSIVE COMPOUNDS

○Dhesingh RAVI SHANKARAN^a,b, Kiyoshi MATSUMOTO^c, Kiyoshi TOKO^d, Norio MIURA<sup>a

a</sup>Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka, 816-8580, Japan
^bJapan Society for the Promotion of Science, Tokyo,102-8471, Japan
^cGraduate School of Agriculture, Kyushu University, Fukuoka-shi, 812-8581, Japan
^dGraduate School of Information Science and Electrical Engineering,
Kyushu University, Fukuoka-shi, 812-8581, Japan

We report here the development of highly sensitive surface-plasmon-resonance (SPR) immunoassays for rapid and label-free detection of 2,4,6-trinitrotoluene (TNT). Two conjugates (2,4,6-trinitrophenyl-keyhole limpet hemocyanine (TNPh-KLH) and 2,4,6-trinitrophenol-bovine serum albumin (TNP-BSA)) and four antibodies of different origin (monoclonal anti-TNT Ab (M-TNT Ab), monoclonal anti-TNP antibody (M-TNP Ab), polyclonal anti-TNPh-KLH Ab, (P-TNPh-KLH Ab) and polyclonal anti-TNP antibody (P-TNP Ab) were used in the development of immunoassays. A simple physical-adsorption method was employed for immobilization of the conjugates onto the transduction surfaces and their interactions with antibodies were monitored by SPR. The eight immunosystems were evaluated and compared for the detection of TNT based on the principle of indirect competitive immunoreaction. The immunoassays showed remarkable sensitivity for TNT (2 ppt level) with an immunoreaction time of 36 s.

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２次元ＳＰＲ免疫センサの高感度化

富山大工，NTT-AT

○鈴木正康，羽根新太郎，大島豊弘，入部康敬，飛田達也

DEVELOPMENT OF A HIGHLY SENSITIVE TWO-DIMENSIONAL SPR IMMUNOSENSOR

Masayasu SUZUKI, Shintaro HANE, Toyohiro OHSHIMA,
Yasunori IRIBE, Tatsuya TOBITA

Faculty of Engineering, University of Toyama
Toyama-shi, Toyama 930-8555
NTT Advanced Technologies Corporation
Atsugi-shi, Kanagawa 243-0124

We are developing the lymphocyte micro array chip system for the screening of antigen-specific B lymphocytes, which are necessary for the development of antibody medicines. We focused on a two-dimensional surface plasmon resonance imaging sensor (2D-SPR) as a tool for immunochemical monitoring in the micro well. In this study, mouse IgG in mic ro wells was detected by using the high resolution 2D-SPR which we developed. The micro-well array was prepared with a PDMS film on gold sensor film. Then protein A was immobilized onto the gold. With 10 and 30 micron I.D. micro wells, mouse IgG could be detected by the increase of averaged light intensity of SPR images for micro-wells. Sensitivity could be extremely improved by the optimization of measurement angle, exposure time, light source intensity and so on. These results show the possibility of the real-time monitioring for the antibody production by a B lymphocyte in a micro well.

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インビボ測定用フレキシブルグルコースセンサの開発

徳島大工,　東洋精密工業^*,　カンザス大学^**

○高岡宏樹,　安澤幹人,　清水利泰^*,　今井信治^*,　Raeann Gifford^*,　George S. Wilson^**

DEVELOPMENT OF FLEXIBLE GLUCOSE SENSORS FOR IN VIVO MEASUREMENT

Hiroki TAKAOKA, Mikito YASUZAWA, Toshiyasu SHIMIZU^*, Shinji IMAI^*,
Raeann GIFFORD^*, George S. WILSON^**

Department of Chemical Science and Technology, The University of Tokushima,
Tokusima 770-8506, Japan
^*Toyo Precision Parts MFG. Co., Ltd., Kashihara, Nara 634-0836
^**Department of Chemistry, University of Kansas,
Lawrence, Kansas 66045, USA

Important design considerations for in vivo type glucose sensors include miniaturization and flexibility, specificity, biostability, long useable life span, and safety. In the design of the sensor, miniaturization of the sensor is of primary importance. Miniaturization and flexibility of the sensor will help reduce the damage to the tissue from sensor implantation. Sensors fabricated from small diameter platinum (<0.1mm) can be brittle, therefore create a greater risk of breakage. In this study, flexible super-elastic Ni-Ti alloy wire was used as the core material with platinum thin film sputtered on its surface. A comparison of the sensor performance between platinum wire and platinum sputtered Ni-Ti wire is demonstrated. Glucose oxidase immobilization was performed by crosslinking with glutaraldehyde and bovine serum albumin. The sensor was fablicated with an integral Ag /AgCl reference to facilitate in vivo testing. This in vivo type glucose sensor showed remarkable anti-interferent selectivity, moreover with a linearity range extending up to 22.4 mM in the phosphate buffer solution.

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インビボ測定用マルチチャンネルセンサの開発

徳島大工,　東洋精密工業^*,　カンザス大学^**

○安澤幹人,　古川晋也,　高岡宏樹,　Raeann Gifford^*,　George S. Wilson^**

DEVELOPMENT OF A MULTICHANNEL BIOSENSOR FOR IN VIVO MEASUREMENT


Mikito YASUZAWA, Shinya FURUKAWA, Hiroki TAKAOKA, Raeann Gifford^*,　George S. Wilson^**

Department of Chemical Science and Technology, The University of Tokushima,
Tokusima 770-8506, Japan
^*Toyo Precision Parts MFG. Co., Ltd., Kashihara, Nara 634-0836
^** Department of Chemistry, University of Kansas,
Lawrence, Kansas 66045, USA

Glucose/lactate dual-channel needle type biosensor with the total diameter of less than 250 μm was fabricated by the combination of glucose oxidase (GOx) immobilized tube electrode and lactate oxidase (LOx) immobilized wire type electrode. GOx immobilized tube electrode was prepared by the formation of sensing site on Pt-coated polyimide tube and immobilizing GOx by electrodeposition of GOx followed by electropolymerization of o-phenylenediamine. LOx immobilized wire type electrode was also prepared by first enzyme electrodeposition step and then electopolymerization step. Both GOx immobilized tube electrode and LOx immobilized wire type electrode showed good response and showed good linear response up to 15 mmol dm-3 in both 0.1 mol dm-3 phosphate buffer solution (pH 7.4) and in horse serum. No crosstalk was observed when glucose/lactate dual-channel needle type biosensor was tested in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). In vivo measurement in rats with the dual channel sensors is under investigation.

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尿分析用マイクロプレーナ型アンペロメトリック胆汁酸バイオセンサーの開発

産総研バイオニクス研究センター ^a、株式会社タニタ ^b、
東京工科大バイオニクス学部 ^c

○小出　哲^a、伊藤　成史^b、輕部　征夫^a, ^c

DEVELOPMENT OF A MICRO-PLANAR AMPEROMETRIC BILE ACID
BIOSENSOR FOR URINE ANALYSIS

SATOSHI KOIDE ^a, NARUSHI ITO ^b and ISAO KARUBE ^{a, c}

^a National Institute of Advanced Industrial Science and Technology,
Research Center of Advanced Bionics, clo Katayanagi Advanced Research
Laboratories, 1404-1 Katakura, Hachioji, Tokyo 192-0982
^b TANITA Corporation, 1-14-2, Maeno-cho, Itabashi-ku, Tokyo 174-8630
^c School of Bionics, Tokyo University of Technology, 1404-1 Katakura,
Hachioji, Tokyo 192-0982

In this work, bile acid biosensor was constructed by electrochemical technique. The electrodes of the sensor chip were manufactured by sputtering of platinum and silver onto the substrate surface. The sensor chip was coated with nafion(r) using spin-coater. Bile acid biosensor was fabricated as follows: Mixed enzyme solution (bile acid sulfate sulfatase (BSS), β-hydroxysteroid dehydrogenase (β-HSD) and NADH oxidase (NHO) were dissolved in distilled water) with glutaraldehyde was placed onto the electrode surface of the sensor chip and then spread by spin-coater and furthermore was reacted (cross-linked by glutaraldehyde) for 24 hours at 4℃. Glycolithocolic acid 3-sulfate (sulfated bile acid) was used as a test sample. Because sulfated bile acid is about 60% of bile acids in urine. The electrochemical measurement was carried out in a TES buffer (pH 7.5) containing 150 mM NaCl at room temperature. There was relationship between concentration of bile acid and current value. The dynamic range of the sensor chip was 0 〜 100 μM for bile acid. Additionally, bile acid in the urine specimen could be detected using this bile acid biosensor. We present a rapid, simple and high sensitivity biosensor of bile acid.

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産総研　バイオニクス研究センター^a、（株）タニタ^b、東京工科大^c

○稲葉　洋平^a、伊藤　成史^b、横山　憲二^a、輕部　征夫^{a, c}

Novel electrochemical measurement of 8-hydroxy-2'-deoxyguanosine in urine

Yohei INABA ^a), Narushi ITO ^b), Kenji YOKOYAMA ^a) and Isao KARUBE ^{a, c)}

^a)National Institute of Advanced Industrial Science and Technology (AIST),
c/o Katayanagi Advanced Research Laboratories, 1404-1 Katakura-Machi,
Hachiouji, Tokyo 192-0982

^b)TANITA Corporation, 1-14-2, Maeno-cho, Itabashi-ku, Tokyo 174-8630

^c)Tokyo University of Technology, 1404-1 Katakura-Machi, Hachiouji, Tokyo 192-0982

8-Hydroxy-2’-deoxyguanosine (8-OHdG) contained in urine is a biomarker of
oxidative stress. In this study, we have developed an effective solid phase
extraction (SPE) method when urinary 8-OHdG is measured by high performance
liquid chromatography coupled to an electrochemical detector (HPLC-ECD). The
SPE consists of two-steps procedures, i.e., reverse phase chromatography
using C18 and strong cation exchange chromatography. The procedures removed
the interference materials in urine. As the results, the detection of
urinary 8-OHdG was useful.

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ウレアーゼ・ベンゼンジチオール・ヒドロキノン混合電解重合膜を用いた
過酸化水素の選択的電解酸化に関する研究

（埼玉工大院工）

○ 関岡 直行、佐藤 智洋、内山 俊一

STUDY ON THE SELECTIE ELECTRODE OXID ATION OF HYDROGEN PEROXIDE USING ELECTROPOLYMERIZED MEMBRANE COMPOSED OF UREASE <BENZENETHIOL.
AND HYDROQUINONE

Naoyuki.SEKIOKA, Tomohiro.SATO, Shunichi.UCHIYAMA

Department of Materials & Science, Graduate School of Engineering,
Saitama Institute of Technology. 1690 Fusaiji Okabe Saitama 369-0293 Japan

Urease strongly adsorbs onto the platinum electrode surface.
Benzenedithiol and hydroquinone mixture was electropolymerized by using urease adsorbed platinum electrode. The mixed membrane composed of urease, benzenedithiol, and hydroquinone should be formed, because S-S bonds are formed among these compounds. In this study we measured the electrode oxidation currents of L-ascorbic acid, uric acid, L-cysteine and hydrogen peroxide by using platinum electrode coated by the mixed membrane.
This membrane has very small holes with highly selective permeability of compounds.
We found that the ratios of the electrode oxidation current values of L-ascorbic
L-ascorbic acid, uric acid and L-cysteine to hydrogen peroxide was 1:10000, 1:2000 and 1:10000 respectively. However, these ratios became significantly worse measured by platinum electrode modified by electropolymerized membrane composed of benzenedithiol and hydroquinone without urease and they were found to be 1:150, 1:150 and 1:200, respectively. These result indicated that hydrogen peroxide can pass through inner urease, in contrast to other molecules. This is probably because the molecular size of hydrogen peroxide is smaller than the other compounds and a protein has very strong affinity to hydrogen peroxide.

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電気化学酵素免疫測定法によるナトリウム利尿ペプチドホルモン検出

産総研

○三重安弘^*、大須賀友美佳^*、平野悠^*、丹羽修^**、水谷文雄^*

HIGHLY SENSITIVE MEASUREMENT OF ATRIAL NATRIURETIC PEPTIDE BY
ELECTROCHEMICAL ENZYME IMMUNOASSAY

Yasuhiro MIE^*, Yumika OSUGA^*, Yu HIRANO^*, Osamu NIWA**, Fumio MIZUTANI^*

National Institute of Advanced Industrial Science and Technology
(AIST), ^*Hokkaido Center, 2-17-2-1, Tsukisamu-higashi, Sapporo,
062-8517, ^**Tsukuba Center, 1-1-1, Higashi, Tsukuba, 305-8566

α-Human atrial natriuretic peptide, a marker peptide hormone for heart diseases, was determined at femtomolar levels by an electrochemical enzyme immunoassay. Alkaline phosphatase (ALP) was used as a labeling enzyme. Changes in ALP activity were monitored using a lipid-modified glucose oxidase electrode based on bioelectrocatalytic redox cycling. p-Aminophenol, the product of the ALP enzyme reaction, was electrochemically oxidized at the electrode to p-iminoquinone, and then reduced back by glucose oxidase which was stably immobilized on the electrode surface. The consumption/regeneration cycle of p-aminophenol resulted in a great enhancement in the sensitivity of the enzymatic immunoassay.

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^aDepartment of Materials & Science, Graduate of School of Engineering,
Saitama Institute of Technology, 1690 Fusaiji Okabe, Saitama 369-0293, Japan

^ｂAnshun University of Science and Technology,185 Qianshan Zhong Road,
Anshan, Liaoning, China

A new amperometric uric acid (UA) sensor is developed that is based on the immobilization of uricase to the homogeneous polystyrene (PS) membrane with polymaleimidestyrene (PMS) as dispersant. The reduction current can be observed when uric acid solution is added at lower potential than -0.5 V vs. Ag/AgCl and a novel amperometric determination method of uric acid has been developed by means of the electrode reduction of the oxygen. The good linear calibration curve of uric acid concentration was obtained in a low concentration range from 5μM to 155μM. The present uric acid sensor of low price, easy preparation, and ambulatory use has an effective merit that the interference of ascorbic acid can be eliminated.

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触媒素子を固定化したDNA-ポリアミン複合膜を認識素子とする
アンペロ メトリックバイオセンサ

埼玉工大工

○長谷部　靖、Tingting Gu

AMPEROMETRIC BIOSENSOR BY THE USE OF CATALYTIC
ELEMENT-INCORPORATED DNA-POLYAMINE COMPLEX MEMBRANE
AS A NOVEL RECOGNITION INTERFACE

Yasushi HASEBE, Tingting GU

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

Copper ion was immobilized into the DNA/polyamine complex membrane prepared on the glassy carbon (GC) electrode.
The circular dichroism (CD) spectrum of the DNA-Cu(II)/PAA membrane in wet state showed that the DNA exists in B-like form within the membrane. The copper ion embedded in the DNA/PAA layer exhibited good electrochemical behaviors, and the electrochemical rate constant between the immobilized copper ion and the GC electrode surface was estimated to be 26.4s-1. The resulting DNA-Cu(II)/PAA/GC electrode showed an excellent electrocatalytic activity for the H₂O₂ reduction, based on the Cu(II)/Cu(I) redox cycle. Even in the presence of dissolved oxygen, the DNA-Cu(II)/PAA/GC electrode exhibited highly sensitive and rapid (response time, less than 5 s) response to H₂O₂. The steady-state cathodic current responses of the sensor obtained at -0.2 V vs. Ag/AgCl in air-saturated 50 mM phosphate buffer (pH 5.0) increased linearly up to 135μM with the detection limit of 50 nM. The DNA-Cu/PAA/GC electrode was applicable to oxidase-biosensors.

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フェロセンボロン酸を用いたリポポリサッカライドの電気化学的検出

JST-CREST、産総研

○加藤大、飯島誠一郎、佐藤縁、Jia Jianbo、栗田僚二、水谷文雄、丹羽修

ELECTROCHEMICAL DETECTION FOR LIPOPOLYSACCHARIDE USING FERROCENYLBORONIC ACID

Dai KATO, Seiichiro. IIJIMA, Yukari SATO, Jianbo JIA, Ryoji KURITA,
Fumio MIZUTANI, Osamu NIWA

JST-CREST, 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan;
National Institute of Advanced Industrial Science and Technology,
1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan

　We describe a novel electrochemical technique for lipopolysaccharide (LPS) based on the current change of rocenenylboronic acid (FcB) caused by the interaction with glycosyl units of LPS. To improve the sensitivity and detection limit, we successfully employed current amplification for FcB with an enzyme-modified electrode. The enzyme-modified electrode was constructed from a gold electrode modified with a bovine serum albumin membrane immobilizing diaphorase. The current response for FcB decreased in association with its complexation with glycosyl units of LPS, and this current decreases caused by LPS was also amplified due to the recycling process. In addition, the enzyme-modified electrode exhibited a rapid response for LPS (5 min). The detection limit of LPS from Escherichia coli O127:B8 was as low as 50 ng/ml.

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スクリーン印刷電極を用いた簡易残留農薬センサ

北陸先端大材料科学^a、富山県農業試験場^b、北斗科学産業（株）^c、バイオデバイステクノロジー^d

永谷尚紀^a,近江みゆき^a,Kagan Kermana,中田均^b,近藤兼司^c,牛島ひろみ^d,高村禅^a,○民谷栄一^a

RESIDUAL PESTICIDES DETECTION SENSOR USING SCREEN PRINTED ELECTRODE.

Naoki NAGATANI^a, Miyuki ChIKAE^a, Kerman KAGAN^a, Hitoshi NAKADA^b,
Kenji KONDO^c, Hiromi USHIJIMA^d, Yuzuru TAKAMURA^a, Eiichi TAMIYA^a

^aSchool of Materials Science, Japan Advanced Institute of Science and Technology,
1-1 Asahidai, Nomi City, Ishikawa 921-1292
^bToyama Agricultural Experiment Station, 1124-1 Yoshioka, Toyama City, Toyama 939-8153
^cHokuto Science Industry Co., 435-5 Takariya, Toyama City, Toyama 930-0897
^dBiodevice Technology Ltd., 2-13 Asahidai, Nomi City, Ishikawa 923-1211

Organophorus and carbamate pesticides as insecticides are widely used in agriculture. These pesticides inhibit activity of acetylcholinesterase (AChE) as a key nerves system enzyme. This inhibition uses for insecticide, but also, this function plays the same as that human transmission of nerve impulse is impossible. and there are some problems about foods safety and environmental pollution. In some case, pesticide residue can be detected in agricultural products. It is a serious problem to human health and environmental. The standard methods for measuring residual pesticides are based on gas chromatogaraphy (GC) coupled with mass selective detector (MS) or high performance liquid chromatography (HPLC). In this report we developed quick and sensitive residual pesticides detection sensor using screen printed electrode to measure AChE activity.

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ALP-固定化物充填カラムを用いた亜鉛イオンのSIA

神奈川工科大工

○佐藤生男，原田知幸，��橋久美子，飯田泰広

SIA OF Zn(II) IONS USING A COLUMN PACKED WITH ALP-IMMOBILIZED BEADS

Ikuo SATOH, Toshiyuki HARADA, Kumiko TAKAHASHI, Yasuhiro IIDA

Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute
of Technology1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken, 243-0292, Japan

Use of a column packed with alkaline phosphatase (ALP) beads as a recognition element in combination with a sequential-injection analysis (SIA) system was tested for determination of zinc(II) ions. The enzymes covalently immobilized onto porous glass beads with controlled pore size (24.2 nm) were packed into a small polymer column. The enzyme-column was placed into a water-jacketed holder(303 K), which was incorporated into the system equipped with a flow-through cell connected to a UV/VIS detector. The catalytic activi ty was assessed by monitoring variations in absorbance at 405 nm attributable to formation of p-nitrophenol in the hydrolysis of p-nitrophenyl phosphate as substrate solution. Exposing the column to 20 mM EDTA (pH 4.0) caused marked decrease in absorbance at 405 nm. Then, increase in absorbance attributable to subsequent introduction of 1.0 mM zinc(II) ions was observed.
The activity partially reactivated was a function of zinc(II) ions introduced. Thus, determination of zinc(II) ions in a dynamic range of 0.01 to 0.1 mM could be photometrically achieved with use of a SIA system.

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分子鋳型ステロールセンサの開発と非侵襲計測

阪府大　先端セ

○椎木弘，深澤聡，長岡勉

Development of Molecularly Imprinted Sterol Sensor and Non-invasive Detection

Hiroshi Shiigi, Satoshi Fukazawa, Tsutomu Nagaoka

Frontier Science Innovation Center, Osaka Prefecture University,
1-2 Gakuen-cho, Sakai 599-8570

Control of the total cholesterol level in the body plays an important role for preventing life-style related diseases. Now, the measurement of cholesterol level in the clinical institution is carried out by using absorption photometer with the enzymatic reaction. However, the conventional method is troublesome due to the necessities of going to a hospital for invasive-collecting blood and using the enzyme reaction through many procedures. On contrary, about 11 % of the body's cholesterol is found in the skin at the same rate as in blood, according to the United States FDA. Therefore, we focus on a simple electrochemical detection and non-invasive measurement of skin cholesterol using the molecularly imprinted self-assembled monolayer electrode (MISAM).

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