Vol. 21, Supplement B (2005)

Abstracts

スクリーン印刷を用いて作製した銀塩化銀参照電極

東理大理工

柳澤　篤、板垣昌幸、渡邉邦洋

SILVER-SILVER CHLORIDE ELECTRODE FEBRICATED BY SCREEN PRINTING

Atsuhi YANAGISAWA, Masayuki ITAGAKI and Kunihiro WATANABE

Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science
2641 Yamazaki. Noda-shi, Chiba 278-8510, Japan

Saturated KCl/AgCl/Ag electrode (SSE) was fabricated by a screen printing mehod. The potential of the fabricated SSE was compared with the potential of the commercial SSE. It was found that these potentials were identical, and this result has good reproducibility. The chloride ion sensor was manufactured by using the fabricated SSE. The output voltage obeyed to Nernst equation regarding to chloride concentration. These results indicated the utility of the fabricated SSE.

針型銀／ヨウ化銀参照電極とそのpHセンサへの応用

筑波大学^a、NTT^b、九州大学^c

○橋本正利^a、サンジェイ・アパジャー^a、小島慎平^a、鈴木博章^a、林勝義^b、砂川賢二^c

NEEDLE-TYPE Ag/AgI REFERENCE ELECTRODE AND ITS APPLICATION TO A pH SENSOR

Masatoshi HASHIMOTO^a, Sanjay UPADHYAY^a, Shinpei KOJIMA ^a, Hiroaki SUZUKI ^a,Katsuyoshi HAYASHI ^b, Kenji SUNAGAWA ^c

^a Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1
Tennodai, Tsukuba, Ibaraki 305-8573
^b NTT Microsystem Integration Laboratories, 3-1 Morinosato, Wakamiya,Atsugi,
Kanagawa 243-0198
^c Kyushu University Graduate School of Medical Sciences, 3-1-1
Maidashi,Higashi-ku, Fukuoka, Fukuoka 812-8582

A needle-type liquid-junction reference electrode was developed based on the use of a thin-film Ag/AgI electrode for a potential-determining element. The internal iodide ion concentration was maintained at a constant value determined by the solubility constant of AgI. Iodide ions which might have existed in the external solution were eliminated: they were electrochemically converted into iodine molecules and trapped in a starch matrix filled in the liquid junction. The internal filling solution was exchanged rapidly within several minutes. Changes of several mV occurred in the electrode potential in relation to changes in the external iodine concentration when the iodide ion concentration changed by one order of magnitude in the nM range. When the liquid-junction reference electrode was used with a pH-indicator electrode in solutions containing different concentrations of various interferents, the achieved precision was ± 0.01 pH unit.

高性能メチルアンモニウムセンサの開発

岡山大・院医歯薬¹、徳島文理大・薬²、東京化成³

植田圭介¹、日置英彰²、久保美和²、児玉三明²、高石清香³、横洲博親³、○勝 　孝¹

DEVELOPMENT OF HIGH-PERFORMANCE METHYLAMMONIUM SENSOR

Keisuke UEDA ¹, Hideaki HIOKI ²,, Miwa KUBO ², Mitsuaki KODAMA ², Kiyoka TAKAISHI ³, Hirochika YOKOSU ³, Takashi KATSU ¹

¹ Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8530
² Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514
³ Tokyo Kasei Kogyo Co. Ltd., 6-15-9, Toshima, Kita-ku, Tokyo 114-0003

High-performance methylammonium sensor was developed using p-1,1,3,3-tetramethylbutyl- calix[6]arene-hexaacetic acid hexaethyl ester. This sensor showed the highest response to methylammonium among various organic ammonium ions and inorganic cations, giving the following selectivity coefficients; log k^Pot_CH3NH3⁺,x : C₂H₅NH₃⁺, -0.2; C₃H₇NH₃⁺, -1.4; C₄H₉NH₃⁺, -1.9; C₆H₁₃NH₃⁺, -1.6; phenethylammonium, -1.9; (CH₃)₄N⁺, -3.4; (C₂H₅)₄N⁺, -4.0; Na⁺, -2.8; K⁺, -1.8; Rb⁺, -1.6; Cs⁺, -0.2; NH₄⁺, -2.8. The sensor exhibited a near Nernstian response to methylammonium in the concentration range of 1x10^-5 to 1x10^-2 M with a slope of 58.5 mV per concentration decade in 0.1 M MgCl₂. Formation of a 1:1 complex between p-1,1,3,3-tetramethylbutylcalix[6]arene-hexaacetic acid hexaethyl ester and methylammonium was confirmed by electrospray ionization mass spectrometry.

Electrochemical Oxidation of Disulfide Bonds Contained Compounds at Highly Boron-doped Diamond Electrodes

Tribidasari. A. Ivandini^a,b, Yasuaki EINAGA^a

^aDepartment of Chemistry, Faculty of Science and Technology, Keio University
3-14-1 Hiyoshi, Yokohama 223-8522, Japan
^bChemistry Dept., Faculty Mathematic and Science, University of Indonesia
Kampus Baru UI Depok, Jakarta 16424, Indonesia

Oxidation of disulfide bonds-contained compounds, indluding cystine, cystein and insulin was investigated at highly boron-doped diamond electrodes by using cyclic voltammetry and flow infection analysis. At bare diamond electrode, direct oxidation of the compounds can be performed. However, controlling the termination is required to optimize the condition.

ポリエーテル鎖を持ったキノンの各種非水溶媒中での電気化学特性

東京農工大学大学院共生科学技術研究部・ナノ未来科学研究拠点^a、
日産自動車株式会社 総合研究所　第3技術研究所^b

○水雲智信^a、大井亮^b、岩崎靖和^b、大野弘幸^a

ELECTROCHEMICAL PROPERTY OF POLYETHER-MODIFIED QUINONES IN VARIOUS NON-AQUEOUS MEDIA

Tomonobu MIZUMO^a), Takashi OI^b), Yasukazu IWASAKI^b), and Hiroyuki OHNO^a)

^a) Department of Biotechnology, Tokyo University of Agriculture and Technology,
Koganei, Tokyo 184-0011, Japan
^b) Technology Research Laboratory No.3, Nissan Research Center,
Natsushima-cho, Yokosuka, Kanagawa 237-8523, Japan

Quinones are often used as mediator for electrochemical sensors, especially enzyme based biosensors. However, the solubility of quinoid compounds are generally low both for aqueous and non- aqueous electrolytes. In order to improve this drawback, we synthesized quinones having poly(ethylene oxide) (PEO) chains. The PEO arranged quinones were readily prepared by substitution reaction using chloranyl and the PEO oligomers. The obtained quinones showed low melting point. When tri(ethylene glycol) (TEG) was attached, the quinone was obtained as liquid. The solubility of the quinone was considerably high, for example 1. 0mol L^-1 to CH₃CN at room temperature. The TEG attached ones dissolved freely with various organic solvents. Furthermore, these showed good compatibility with ionic liquids. The electrochemical properties of the obtained quinone were evaluated by dissolving them into various common non-aqueous electrolyte solutions and ionic liquids.

水溶液中における水晶振動子共振周波数の浸漬角度依存特性

鹿大工、産総研

〇吉本　稔、時村　心、吉村俊一郎、黒澤　茂

Immersion angle dependence of the resonant frequency shift of the quartz crystal microbalance in liquids

Minoru YOSHIMOTO, Shin TOKIMURA, Shun-ichiro YOSHIMURA and Shigeru KUROSAWA

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

　We investigated the immersion angle dependence of the resonant frequency shift, ΔF, of the quartz crystal microbalance (QCM) in a Newtonian liquid from the point of view of the QCM oscillation direction. As a result, we have found that only when the surface with the electrode of the QCM is not parallel to the gravity direction, the immersion angle dependence of ΔF appears. Namely, it has become clear that the immersion angle dependence of ΔF has no relation to the QCM oscillation direction.

血液導電率センサの開発

国立リハビリ研、東洋大工

外山　滋、中村正紀、青木一仁、加藤誠志、宇佐美論

DEVELOPMENT OF A BLOOD CONDUCTOMETRIC SENSOR

Shigeru TOYAMA, Masanori NAKAMURA, Kazuhito AOKI, Seishi KATO and Ron USAMI

Research Institute, National Rehabilitation Center for Persons with Disabilities
4-1 Namiki, Tokorozawa, Saitama 359-8555, Japan
Department of Applied Chemistry, Faculty of Engineering, Toyo University
2100 Nakanodai, Kujirai, Kawagoe, Saitama 350-8585, Japan

Two types of blood conductometric sensor have been developed to estimate blood osmotic pressure. The first type sensor has a very simple structure comprising two Pt electrodes on a glass substrate. This sensor requires a very little sample (about 15 μl). Wecould obtain a linear relation between the sensor response and the concentration of serum. The second type sensor has a blood cell filter. This sensor could directly apply preserved animal blood and measure its conductance. The sensor output was independent to the hematocrit of the sample, and exhibited a linear relation with the osmotic pressure.

分子インプリント高分子のゲート効果を利用した有機溶媒系キラルセンシング

芝浦工大，早大理工^*

関根真一、渡邊優太、吉見靖男、服部浩二^*、酒井清孝^*

CHIRAL SENSING IN ORGANIC SOLVENT USING GATE EFFECT OF MOLECULARLY IMPRINTED POLYMER

S. Sekine, Y. Watanabe, Y. Yoshimi, K. Hattori^*, K. Sakai^*

Department of Applied Chemistry, Shibaura Institute of Technology, Minato-ku, Tokyo108-8548, Japan
^*Department of Chemical Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan

Chiral sensing in organic solvent by the gate effect of a molecularly imprinted polymer (MIP) was attempted in this work. We grafted poly-(methacrylic acid-co-ethyleneglycol dimethacrylate) imprinted by D- or L-MIP-ITO or Blank-ITO, respectively. Cyclic voltammetry of ferrocene in dichloromethane was performed with the treated electrode. The effect of the presence of D- or L-PAA in the current were observed. As the results, the anodic current at the D- or L-MIP-ITO decreased (more than 10%) by its template of 5 mM. However it was hardly sensitive to The 5 mM enantiomer of the template. The current of the Blank-ITO was insensitive to either of the PAA. those results show that this gate effect would be potentially applicable for simple amperometric sensors with enantio-selectivity. The sensor can work in organic solvent, which is a remarkable advantage comparing with biosensors using enzymes or antibodies.

VOLTAMMETRIC　SENSING OF UREA BASED ON ELECTRODE OXIDATION OF CARBAMIC ACID PRODUCED BY UREASE REACTION

○Xiuyun WANG^a,b, Ryoichi TOMITA^a, Shunichi UCHIYAMA^a

^aDepartment of Materials & Science、Graduate of School of Engineering,Saitama Institute of Technology,
1690 Fusaiji Okabe, Saitama 369-0293
^ｂAnshun University of Science and Technology
185 Qianshan Zhong Road, Anshan, Liaoning, China

The oxidation current can be observed when carbamate ammonium aqueous solution is electrolyzed at higher potential than 1.0 V vs. Ag/AgCl. Carbamic acid is produced from urea as an intermediate of urease reaction. As well as carbamate ammonium solution, the oxidation current was observed when urea is added into urease solution and a novel amperometric determination method of urea has been developed by means of the electrode oxidation of carbamic acid formed in urease reaction. The good linear relationship of urea concentration and cyclic voltammetric current was obtained in a concentration range from 5mM to 100mM. The present urea sensor has an effective merit that the interference of ammonia can be eliminated.

酸性ウレアーゼカラム一体型マイクロフローガス拡散デバイスによる尿素の高感度計測

飯田泰広、千葉豊生、佐藤生男

神奈川工科大学応用化学科

SENSITIVE DETERMINATION OF UREA WITH USE OF AN IMMOBILIZED ACID UREASE COLUMN EMBODIED INTO A MIMICROFLOW GAS DIFFUSTION DEVICE

Yasuhiro IIDA, Yoshinori CHIBA and Ikuo SATOH

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

A novel gas diffusion device armed with immobilized enzymes was developed and the device was applied to flow-injection analysis (FIA) of urea with an acid urease column as a recognition element. A flow-type of the biosensing system used in this study was assembled with a sample injection valve, a gas-diffusion device armed with the immobilized acid urease column, and a flow-through cell attached to a UV/VIS detector. The gas diffusion device has a double tubing structure. The inner tubing was a gas permeabetubing and bromothymol blue as a coloring agent was pumped through in this tuving. The outer tubing was PTFE tubing for flowing carrier solution and a monolithic silica column was constructed in this bubing and acid urease was immobilized onto the silica monolith. Standard urea solutions were measured through monitoring variations in absorbance resulting from pH shift due to CO2 molecules enzymatically generated under acidic condition. A wide, linear relationship was obtained between the concentration of urea (1.25 - 1000μM) and the change in absorbance. This FIA system gave higher sensitivity than that previous system did (25 - 500μM). The proposed FIA system was applied to determination of urea in real samples.

アスコルビン酸ブロック電極のグルコースセンサへの応用

久保いづみ、山本佳代子、前原信義

創価大工

Application of the Surface Modified-Electrode for the blocking of Ascorbic Acid to a Glucose Sensor

Izumi KUBO, Kayoko YAMAMOTO, Nobuyoshi MAEHARA

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

A surface of gold electrode was modified with a self-assebled monolayer (SAM) order to protect the oxidation of ascorbic acid, which exists in biological fluid. The electrode was prepared by the modification with 7-carboxyheptanethiol(7C) and 8-aminoctanethiol(8A). On the modified electrode, GOD was immobilized with use of ethylenediamine(ED) and/or glutaraldehyde(GA). Oxidation of glucose was mediated by Co(phen)₃²⁺. When GOD was immobilized on the 7C SAM modified gold electrode with 0.5% ED and 2.5% GA, the GOD-immobilized electrode showed most selective response to glucose at 200 - 250mV, which was the oxidation potinatial of Co(phen)₃²⁺. With the electrode, glucose was determined to 0.5mM at room emperature.

微細針状グルコースセンサを用いた体内グルコース濃度連続測定評価

徳島大工、東洋精密工業^*、カンザス大学^**

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

THE CONTINUOUS MONITORING ESTIMATION USING FINE NEEDLE TYPE IN VIVO GLUCOSE SENSORS

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

Department of Chemical Science and Technology, The University of Tokushima
2-1 Minamijosanjima, Tokusima 770-8506, Japan
^*Toyo Precision Parts MFG. Co., Ltd.
376-1 Shindo, Kashihara, Nara 634-0836, Japan
^** Department of Chemistry, University of Kansas
1251 Wescoe Hall Dr., Lawrence, KS 66045, USA

There are various desirable characteristics to consider when designing in vivo type glucose sensors; including miniaturization, specificity, biostability, long useable life span, and safety. Miniaturization of the sensor is an important feature because smaller devices are less invasive, both physically and psychologically. A miniaturized device will excite fewer pain receptors in the skin and will cause less tissue damage, thus less pain and improved performance. However, since miniaturization can lead to easy deformation and breakage of the sensor, it is difficult to fabricate sensors less than 200 μm diameter that retain enough flexibility and strength to insure proper in vivo function. In this study, super-elastic Ni-Ti alloy wire was used as the core material with platinum thin film sputtered on its surface. Glucose oxidase was then immobilized on the platinum surface and functional glucose sensor characteristics were investigated. In vivo measurement with the new flexible glucose sensor was attempted.

微小化学センサ・センシングチップの開発と応用

産総研

脇田慎一

DEVELOPMENT AND APPLICATION OF MICRO CHEMICAL SENSORS AND MICRO SENSING SYSTEM

Shin-ichi WAKIDA

Human Stress Signal Research Center,
National Institute of Advanced Industrial Science and Technology (AIST)
Ikeda, Osaka 563-8577

Micro chemical sensors and micro sensing system are of great interest for sensor network system. We have intensively researched and developed for ISFETs and electrophoretic microfluidics. To realize ISFETs for biomedical and environmental applications, we studied sensing materials, sensor matrixes and sensor monitoring systems as well as scientific investigation for sensor mechanism. To realize microfluidics for biomedical and environmental applications, we also studied fabrication technique, microfluidic control and microfluidic monitoring system. I summarized a brief review of my topic of our studies.

マイクロ針状グルコースセンサの作製

徳島大工、東洋精密工業^*、カンザス大学^**

○野本信一、高岡宏樹、安澤幹人、清水利泰^*、今井信治^*、Raeann Gifford^**、George S. Wilson^**

FABRICATION OF NEEDLE TYPE MICRO GLUCOSE SENSORS

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

Department of Chemical Science and Technology, The University of Tokushima
Tokushima-shi, Tokushima 770-8506, Japan
^*Toyo Precision Parts MFG. Co., Ltd., Yamatotakada-shi, Nara 635-0066
^** Department of Chemistry, University of Kansas,
1251 Wescoe Hall Dr., Lawrence, KS 66045, USA

Glucose sensors with the diameter of less than 10 ?m were fabricated using super-flexible Ni-Ti alloy wire as a core material. The 150 ?m diameter of Ni-Ti alloy wire was reduced by a continuous dipping operation in etching solution. Ni-Ti surface was sputter coated with Pt film. The Pt surface was covered with silica leaving the unetched end bare for electric contact. Silica on the etched tip was removed in order to prepare sensing cavity. Glucose oxidase (GOx) was immobilized on the sensing cavity by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) in the presence of GOx. Performance characteristics of the fabricated micro glucose sensor were determined in phosphate buffered saline (pH 7.4). The response current increased with the increase of glucose concentration up to 22 mmol dm-3. However, the linear range went up to 11 mmol dm-3. The response time to 90% maximum current for the micro glucose sensor was 20 seconds.

非特異吸着抑制表面加工技術の開発

(徳島大工)○力武浩太郎、小出崇志、二神規通、古川晋也、安澤幹人

DEVELOPMENT OF SURFACE PROCESSING TECHNIQUE FOR NONSPECIFIC ADSORPTION INHIBITION

Kotaro RIKITAKE, Takashi KOIDE, Norimichi FUTAGAMI, Shinya FURUKAWA, Mikito YASUZAWA

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

The adaptation of metals surface was performed by the surface reaction of perhydropolysilazane (PZ) in the presence of polyethylene glycol (PEG). Surface hydrophilic property was able to control by the reaction of PEG with PZ and the usage of PEG at various molecular weight. Biocompatibility of platinum treated with PZ and PEG was evaluated by blood platelet adhesion test. The treatment significantly improved the biocompatibility of platinum. Potentiality and utility of new surface processing technique for biocompatibility treatment and nonspecific adsorption inhibition was strongly suggested.

バブル型集積化送液システムとそのバイオセンシングへの応用

筑波大学

佐藤　航、清水義文、橋本正利、鈴木博章

BUBBLE-TYPE INTEGRATED MICROFLUIDIC TRANSPORT SYSTEM AND ITS APPLICATION TO BIOSENSING

Wataru SATOH, Yoshifumi SHIMIZU, Masatoshi HASHIMOTO and Hiroaki SUZUKI

Graduate School of Pure and Applied Science, University of Tsukuba
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan

Microfluidic transport, mixing, and sensing were achieved using only integrated microfluidic and sensing components. The basic structure fo the pumps and valves consisted of three-electrode systems and a PDMS diaphragm to separate the electrolyte solution from the sample solution in the micro flow channel. Hydrogen bubbles were grown or shrunk around a platinum black working electrode formed on the walls of anisotropically etched through-holes in a siliconsubstrate. This caused the deformation of the PDMS diaphragm, and a solution in the flow channel was mobilized. Two solutions could be introduced from two infection ports and transported through the flow channels with the help of check valves based on the same principle. By stopping the flows, the solutions could be mixed in the mixing channel. To demonstrate its applicability to micro analysis systems, two solutions were infected, mixed and allowed to react in the mixing channel. The detection of hydrogen peroxide and L-glutamate was demonstrated with this device.

ＰＤＭＳマイクロ流体デバイスの酸素透過性評価

東北大院環境^a，機能性ペプチド研究所^b，東北大学先進医工^c，防衛大学校^d，

珠玖　仁^a、斉藤剛史^a、呉　靖宇^a、安川智之^a、末永智一^a,c、星　宏良^b、横尾正樹^c，阿部　宏之^c、山田　弘^d

OXYGEN PERMEATBILITY FOR POLY(DIMETHLSILOXANE) (PDMS) CHARACTERIZED BY FEEDBACK-MODE SCANNING ELECTROCHEMICAL MICROSCOPY

Hitoshi SHIKU^a, Takeshi SAITO^a, Ching-Chou WU^a, Tomoyuki YASUKAWA^a, Tomokazu MATSUE^a,c, Hiroyoshi HOSHI^b, Masaki YOKOO^c, Hiroyuki ABE^c, Hiroshi YAMADA^d

^aGreduate School of Environmental Studies, Tohoku University, Sendai 980-8579, Japan
^bInstitute for the Functional Peptide, Yamagata 990-0823, Japan
^cTohoku University Biomedical Engineering Research Organization(TUBERO), Sendai 980-8579, Japan
^dDepartment of Applied Chemistry, National Defense Academy, Kanagawa 239-8686, Japan

Poly(dimethylsiloxane) (PDMS) is now recognized as a most ideal material for manufacturing micro-devices in the bio-micro-electromechanical systems (bio-MEMS), because of its significant charactristics to easily design relatively complicated three-dimensional structures. The high permeability of oxygen is another ubiquitous nature of PDMS to be applied for micro-culture, micro-circulation or further convoluted operationswith various valuable living cells, spheroids, embryos and tissues. Feedback-modescanning electrochemical microscopy (FB-SECM) has been applied to quantitatively characterize the oxygen permeation behaviors for the PDMS and the surface-modified PDMS by locating the microelectrode probe very close to the sample surfaces. We show here the oxygen permeability for PDMS is possibly affected by O₂ plasma irradiation and albumin adsorption at the PDMS surfaces. As these surface modifications are often involved in a set of the device-fabrication procedure, careful attention concerning on oxygen permeation of the PDMS and the modified-PDMS should be required for the device-design.

微小電極を組み込んだ密閉型マイクロウェルアレイチップによる単一細胞活性計測

東北大院環境¹，(独)国立環境研²

○沼井 大輔¹，長峯 邦明¹，安川 智之¹，珠玖 仁¹，小出 昌弘²，板山 朋聡²，末永 智一¹

HERMETICALLY SEALED ELECTROCHEMICAL MICROWELL ARRAY CHIP FOR SINGLE CELL ANALYSIS

Daisuke NUMAI¹, Kuniaki NAGAMINE¹, Tomoyuki YASUKAWA¹, Hitoshi SHIKU¹, Masahiro KOIDE², Tomoaki ITAYAMA², Tomokazu MATSUE¹

¹Graduate School of Environment Studies, Tohoku Universuty
6-6-11 Aramaki Aoba , Aoba-ku, Sendai 980-8579
²National Institute for Environmental Studies
16-2 Onogawa, Tsukuba 305-8506

Hermetically sealded electrochemical microwell array chip has been developed for the single cell or molecular-level analysis. A small number of target cells was enclosed into a three dimensional minute well with a microelectrode in the chip, which was photolithographically fabricated using a glass substrate and a resist polymer. The photosynthetic activity of the entrapped cells was characterized based on reduction current of oxygen at the microelectrode in the well. The results indicated that as low as 300 algae cells were successfully detected from the oxygen generation due to photosynthetic activity. It is expected that this device can be applied to integrated ultra-sensitive biosensors.

オンデマンド型マイクロ流路抗体チップの開発

東北大院工^a、院環境科学^b

○橋本　昌彦^a、　梶　弘和^a、　川島　丈明^a、　安部　隆^a、　末永　智一^b、　西澤　松彦^a

DEVELOPMENT OF ON-DEMAND TYPE OF MICROFLUIDIC PROTEIN CHIP USING ELECTORCHEMICAL BIO-LITHOGRAPHY

Masahiko HASHIMOTO ^a, Hirokazu KAJI a, Takeaki KAWASHIMA ^a, Takashi ABE ^a, Tomokazu MATSUE ^b, Matsuhiko NISHIZAWA ^a

^a Department of Bioengineering and Robotics, Graduate School of Engineering,

^b Department of Environmental Studies, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan

The dynamic control of surface properties and spatial presentation of functional molecules within a microfluidic channel is important for the development of diagnostic assays and bioreactors. We have developed a surface patterning technique based on an electrochemical method, "electrochemical bio-lithography'', which enables the localized immobilization of biomolecules and is simple enough to be integrated into the miniaturized and semi-closed systems such as microchannels. Here, we present a strategy for the real-time immobilization of proteins in a microfluidic device. The combination of the electrochemical bio-lithography with multiple fluidic laminar flows offers variations in obtainable protein patterns within a microchannel since this lithographic treatment can be conducted repeatedly even in the channel. The micropatterned antibodies within the channel serve as the platform for the efficient and convenient immunoassay, opening new possibilities for the microchannel-bas
ed bioassays.

キュウリの微少組織を吸着固定した多孔性炭素材料を用いる簡易型ビタミンCセンサーの開発

埼玉工大院工

○冨田亮一、内山俊一

DEVELOPMENT OF CONVENIENT VITAMIN C SENSOR USING POROUS CARBON MATERIAL ADSORBED BY CUCUMBER MICROTISSUE.

Ryoichi TOMITA, Shunichi UCHIYAMA

Department of Materials and Engineering, Graduate School of Engineering, Saitama Institute of Technology
1690 Fusaiji, Okabe, Saitama 369-0293

The utilization of biological tissues containing large amount of enzymes is effective for fabricating inexpensive enzyme sensors, but the lifetime of enzyme in biological tissue is rather short due to its putrefaction compared with the enzyme sensors using immobilized purified enzyme membrane. In this work, the cucumber juice containing ascorbte oxidase (ASOD) was used to immobilize ASOD to porous carbon material by adsorption, and this modified carbon material was combined with oxygen electrode to fabricate L-ascorbic acid (AsA) sensor. We found that an excellent linear relationship between AsA concentration and current response was obtained and the stability of sensor response was longer than at least one month. The reason why lifetime of enzyme sensor increases is that microdebris of tissue is confined into the micropores of the carbon fibers, and the leaking or unfolding of enzyme does not take place. The porous carbon material adsorbed by purified ASOD also showed similar long life time and the chemically amplified response (detection limit was 2.0×10^-8M) was observed by 0.05 M dithiothreithol(DTT). However, in case of microtissue adsorbed carbon material, the amplification of sensor response using DTT was not observed, because access of DTT to enzyme in tissue is difficult, differing from purified enzyme.

フェロセン修飾電極を用いた過酸化水素の高感度検出
―酵素免疫反応への応用を目指して―

北大院理^a、産総研ゲノムファクトリー研究部門^b

HIGHLY SENSITIVE HYDROGEN PEROXIDE DETECCTION USING FERROCENE MODIFIED GOLD ELECTRODE

Shinichiro AMENUMA^a, Yasuhiro MIE^b, Fumio MIZUTANI^b, Kohei UOSAKI^a

^aDivision of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810
^bResearch Institute of Genome-Based Biofactory, National Institute of Advanced Industrial Science and Technology(AIST), Sapporo, Hokkaido 062-8517

The highly sensitive measurement of H₂O₂ using a self assembled monolayer of ferrocene(Fc) on the gold electrode surface was carried out. H₂O₂ solutions containing horseradish peroxidase (HRP) were flowed through the Fc modified gold surface in a thin layer cell to oxidize Fc to ferricinium cation (Fc⁺). The charged Fc⁺ at the gold electrode surface was then electrochemically reduced by applying the potential of -0.05 V (vs. Ag/AgCl). The reductive currents in the obtained amperograms increased with increasing the concentration of H₂O₂ flowed. The linear relation between the current (or electrical charge estimated from the amperogram) and the H₂O₂ concentration was observed up to 100 nM of H₂O₂ with a detection limit of 10 nM. When flowing H₂O₂ solutions without HRP, no significant reductive currents in the amperograms were observed, indicating the catalytic roll of HRP to oxidation of Fc by H₂O₂. Since the active (heme) site of HRP is easily two-electron oxidized by H₂O₂ to be high oxidation state (compound I), it is suggested that this compound oxidizes Fc on the electrode surface.

金属酸化物−金属電極複合型くし形電極の作製とカテコールアミンの選択検出

芝工大工¹, NTT-MI研², 九大³

○太田雅史¹, 林　勝義², 岩崎　弦², 吉見靖男¹, 砂川賢二³, 芳賀恒之²

FABRICATION OF AN INTERDIGITATED HETERO-ARRAY ELECTRODE CONSISTING OF A METAL-OXIDE ELECTRODE AND A METAL-BAND ELECTRODE AND SELECTIVE DETECTION OF CATECHOLAMINE AGAINST ELECTROACTIVE INTERFERENTS

Masashi OOTA¹, Katsuyoshi HAYASHI², Yuzuru IWASAKI², Yasuo YOSHIMI¹,
Kenji SUNAGAWA³, Tsuneyuki HAGA²

¹Department of Applied Chemistry, Shibaura Institute of Technology,
Minatoku, Tokyo 108-8548, Japan
²Microsystem Integration Laboratories, NTT,
Atsugi, Kanagawa 243-0198, Japan
³Department of Cardiovascular Medicine Kyushu University Graduate School of Medical Science,
Fukuoka, Fukuoka 812-8552, Japan

We fabricated an interdigitated array electrode (IDAE) consisting of a metal-oxide electrode and a metal-band hetero-electrode and employed it for the selective detection of catecholamine. We used an indium-tin oxide (ITO) film as the oxidation electrode of IDAE because the ITO was able to suppress response currents from L-ascorbic acid (AA) and uric acid (UA), which are major electroactive interferents in biological fluids. However, the ITO film also suppresses the reduction of quinones including oxidized catecholamine. We developed a simple technique for fabricating hetero IDAE, which also preserves the electrochemical properties of the ITO. When we compared hetero ITO-gold, homo gold-gold IDAEs, we found that the hetero IDAE provided high selectivity for DA detection.

カーボンペースト電極を使用したドーパミンの選択的検出

熊本大

稲田和文、西山勝彦、谷口　功

SELECTIVE DETECTION OF DOPAMINE USING CARBON PASTE ELECTRODES

Kazufumi INADA, Katsuhiko NISHIYAMA, Isao TANIGUCHI

Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University
2-39-1, Kurokami, Kumamoto860-8555, Japan

Detection of dopamine (DA) in the presence of ascorbic acid (AA) at the carbon paste electrodes (CPES) is described. Anodic peak potential of DA was more positive than AA by ca. 190 mV at the electrochemically pretreated CPES in a phosphate buffer solution (pH7.4). Anodic peak current of 2.5 mM DA did not depend on the AA concentration (from 0.1 to 1 mM). Influence of albumin on detection of DA in the presence of AA was investigated, and graphite (crystalline, -300 mesh, Alfa Aesar) was found to be preferable among carbon powders used .

ENZYMATIC LUMINESCENCE DETECTION OF DOPAMINE WITH THE AMINE OXIDASE AND ITS APPLICATION TO REAL TIME OBSERVATION OF NERVE MODEL CELL RESPONSE

Hiroaki SHINOHARA and Feifei OH

Dept. of Material Systems Engineering and Life Science, Faculty of Engineering, Toyama University,
Gofuku 3190, Toyama 930-8555, Japan (e-mail:hshinoha@eng.toyama-u.ac.jp)

Highly sensitive detection method for dopamine was developed by using the bi-enzymatic luminescence reaction to monitor the response of nerve model cells at real time. The effective enzyme for dopamine oxidation was firstly investigated. It was found that tyramine oxidase (TOD) had very high activity for dopamine oxidation to produce hydrogen peroxide. Therefore, the TOD was applied to detect dopamine by coupling with luminol reaction with peroxidase. Dopamine was detected in the concentration range from 10 nM to 1 μM with this method. Finally, the luminescence detection method was applied to observe the activation response of PC12 cell as a nerve model cell. Very quick luminescence generation was observed with a luminescence detector upon acetylcholine stimulation. It demonstrated the quick release of dopamine from the PC12 cells at real time.

簡易型２色光ファイバSPRセンサの基礎特性

静大電子科研^a，静大電研^b，静大工^c

鈴木　均^a、杉本光範^b、松井義和^c、近藤　淳^a,c

FUNDAMENTAL CHARACTERISTICS OF A HANDY-TYPE DUAL-COLOR FIBER OPTIC SPR SENSOR

Hitoshi SUZUKI^a, Mitsunori SUGIMOTO^b, Yoshikazu MATSUI^c, Jun KONDOH^a,c

^aThe Graduate School of Electronic Science and Technology, Shizuoka University
^bResearch Institute of Electronics, Shizuoka University
^cFaculty of Engineering, Shizuoka University
Hamamatsu, Japan

We present the fundamental characteristics of a handy-type dual-color optical fiber surface plasmon resonance (SPR) sensor for sensing refractive index of liquids. Principle of the propsed SPR sensor is based on the differential reflectance method. Two light emitting diodes (LEDs), which are flashing alternately with different wavelengths, are employed as light sources. Changes of reflectance at two wavelengths are proportional to the refractive index change of a sensed medium. MEasurable refractive index range of 1.333 to 1.3616 and the limit of detection (LOD) of 5.2 ×10^-4 were confirmed.

電気化学的SPR法を用いた蛋白濃度測定

国立身体障害者リハビリテーションセンター研究所

○青木 一仁、外山 滋、加藤 誠志

MEASUREMENT OF PROTEIN CONCENTRATION BY THE USE OF ELECTROCHEMICAL SPR SENSOR

Kazuhito AOKI, Shigeru TOYAMA, Seishi KATO

Research Institute, National Rehabilitation Center for the Persons with Disabilities
4-1 Namiki Tokorozawa, Saitama 359-8555, JAPAN

A simple approach of a uric protein sensor was examined. An electrochemical surface plasmon resonance (SPR) sensor was applied to nonspecifically detect proteins such as albumin by the use of direct protein adsorption onto the sensor surface. The potential of sensor surface, made of Au, was controlled to regulate the adsorption behavior of albumin. Appling low potential such as -600mV vs Ag/AgCl, the protein adsorption onto Au was inhibited. SPR response was measured after the repeated potential change. It was correlated to the albumin concentration in a phosphate buffer. Sodium dodecanate was applied to remove the protein adsorbed on the Au surface in order to regulate the sensor. Though the dodecanate might be attracted onto Au surface by the intermittent potential changes of the Au surface, the adsorbed dodecanate was easily removed by applying low potential.

表面プラズモン共鳴(SPR)免疫センサによる２,４-Ｄのラベルフリ-高感度検出

九大産学連携センター ^a、 九大院総理工^b, 九大院薬^c　

Ｋ.Ｖ. ゴビ^a, ○キム スクジン^b, 田中宏幸^c, 正山征洋^c, 三浦則雄^a

SURFACE PLASMON RESONANCE (SPR)-BASED IMMUNOSENSOR FOR HIGHLY SENSITIVE LABEL-FREE DETECTION OF 2,4-D

K.Vengatajalabathy GOBI^a, ○Sook Jin KIM^b, Hiroyuki TANAKA^c,
Yukihiro SHOYAMA^c , Norio MIURA^a

^a Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka 816-8580, Japan
^b Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580, Japan
^c Graduate School of Pharmaceutical Sciences, Kyushu University, Maidashi,
Higashi-ku, Fukuoka 812-8582, Japan

An optical biosensor based on SPR technology for detection of 2,4-D, one of endocrine disrupting chemicals, has been demonstrated employing an indirect competitive-immunoreaction principle. A physically adsorbed ovalbumin-conjugate of 2,4-D (hereafter 2,4-D-OVA) served as the sensing surface and was a stable, closely-packed monolayer. When a mixture of 2,4-D-OVA and free 2,4-D is injected into the sensing system which has already surface-immobilized 2,4-D-OVA, the free 2,4-D inhibits anti-2,4-D-Ab to immunoreact with the sensing surface and the extent of the inhibition is determined. The present SPR immunosensor responds to the presence of 2,4-D as low as 100 pg/ml (ppt). A simple flowing of an acidic glycine buffer (pH 2.0) for less than a minute was performed to regenerate the sensor chip. Reusability of a same chip in quantification of 2,4-D is achieved more than 50 cycles. The cross-sensitivity of the fabricated SPR immunosensor is studied with a few structurally- and environmentally-relevant compounds.

高感度SPR免疫センサのための抗体固定化膜の検討

筑波大^a，産総研^b

黒澤千佳子^a,b、Edmar P. Casa^b、愛澤秀信^b、黒澤　茂^b、鈴木博章^a

CHARACTERIZATION OF IMMOBILIZATION LAYER FOR HIGHLY SENSITIVE SURFACE PLASMON RESONANCE IMMUNOSENSOR

Chikako KUROSAWA^a,b, Edmar P. CASA^b, Hidenobu AIZAWA^b, Shigeru KUROSAWA^b, Hiroaki SUZUKI^a

^aInstitute of Materials Science, University of Tsukuba
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
^bNational Institute of Advanced Industrial Science and Technology (AIST)
1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan

To detect endocrine disruptors in environmental sample and disease markers in human blood, surface plasmon resonance (SPR) sensor is abailable, however, the sensitivity is not enough to detect small molecules. In this study, poly(tert-butylacrylate) brush as an immobilization layer of antibody for immunosensor was grafted on the chemically-activated gold surface via atom transfer radical polymerization (ATRP), ATRP is known as a valid polymerization method to graft well-controlled polymer(1),(2). We grafted poly(tert-butylacrylate) brush on SPR sensor chip and Si wafer, and characterized grafted polymer using XPS, FE-SEM, and GPC. The results show that the polymerization process was done successfully. Additionally, the SPR angle change due to polymer swelling has been able to detect by SPR detector.

高解像度２次元ＳＰＲイメージングセンサを用いたマイクロアレイチップでの免疫センシング

富山大学工学部^a、NTTアドバンステクノロジ^b

○入部康敬^a、春日井崇^a、大島豊弘^a、飛田達也^b、鈴木正康^a

IMMUNOSENSING WITH MICRO-ARRAY CHIPS BY USING A HIGH RESOLUTION TWO-DIMENSIONAL SPR IMAGING SENSOR

Yasunori IRIBE^a, Takashi KASUGAI^a, Toyohiro OHSHIMA^a, Tatsuya TOBITA^b and Masayasu SUZUKI^a

^aFaculty of Engineering, Toyama University, Toyama-shi, Toyama 930-8555, Japan and
^bNTT Advanced Technology Corp., Atsugi, Kanagawa 243-0124, Japan

We are developing novel micro-well array systems for the parallel monitoring of immunoreactions. This system will be used to identify the antigen-specific B lymphocytes and applied to high-throughput antibody production. This micro-well array chip has a quarter million wells on one chip (ca. 20 mm x 20 mm), and diameter of each well is 10 mm and only one cell can be occupied for each well. We focused on a two-dimensional surface plasmon resonance imaging sensor (2D-SPR) as a tool for immunochemical monitoring in a micro well. In this study, mouse IgG in micro wells was detected by using the high resolution 2D-SPR. The micro-well array was prepared with a PDMS film on gold sensor film. Then protein A was immobilized via 4,4’-dithiodibutyric acid (DDA) onto the gold. Even with 30 mm I.D. micro-wells, mouse IgG could be detected by the increase of averaged light intensity of SPR images for micro-wells. These results show the possibility of the real-time monitoring for the antibody production by a B lymphocyte in a micro well.

アパタイト型希土類シリケートLn-Si-Ga-O系酸化物イオン伝導体の調製と応用

愛媛大工

○中村悠一、竹田尚貴、板垣吉晃、青野宏通、定岡芳彦

PREPARATION AND APPLICATION OF IONIC CONDUCTIVE APATITE-TYPE RARE-EARTH GALLIUM SILICATES

Yuuichi NAKAMURA, Naoki TAKEDA, Yoshiteru ITAGAKI, Hiromichi AONO and Yoshihiko SADAOKA

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

Ln_9.33+x/3Si_6-xGa_xO₂₆ (Ln=La, Nd, Sm, 0≦x≦2.0) was prepared by the sintering at 1600℃ for 5h. The conductivity and the sinterability were improved by an increase in x value for the Ln_9.33+x/3Si_6-xGa_xO₂₆ system. The Nd_9.83Si_4.5Ga_1.5O₂₆ sample showed the maximum conductivity 8.97×10^-4S・cm^-1 at 773K, which is comparable with that of Nd_9.83Si_4.5Al_1.5O₂₆. The electron number for O2 gas concentration cell was almost agreed with theoretical value for Ln=Sm, but not for Ln=La, Nd.

炭酸ガスセンサへの応用を目的とした炭酸リチウム-希土類酸化物混合材料の特性評価

愛媛大工

○島本 洋一、山内 充、津村 直樹、板垣 吉晃、青野 宏通、定岡 芳彦

CHARACTERIZATION OF MIXTURE OF LITHIUM CARBONATE AND RARE EARTH OXIDE FOR APPLICATION OF CO₂ GAS SENSOR

Youichi SHIMAMOTO, Mitsuru YAMAUCHI, Naoki TSUMURA, Yoshiteru
ITAGAKI, Hiromichi AONO and Yoshihiko SADAOKA

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

The mixtures of Li₂CO₃ and rare earth oxide (R₂O₃) were investigated for the application of the CO₂ gas sensor. Mixture of Li₂CO₃ and R₂O₂CO₃ was obtained by calcination in CO₂ gas for light rare earth oxide (R=La~Gd), but not for heavy rare earth oxide (R=Dy~Yb) and Y₂O₃. When these mixtures used as an auxiliary phase, the electromotive force (EMF) was very stable compared with that using sole Li₂CO₃.

Effects of Different Additives on the Sensing Properties of NiO Electrode Used for Mixed-Potential-Type YSZ-based Gas Sensors

Vladimir V. PLACHNITSA and Norio MIURA

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

The nano-sized NiO sample was modified by the addition of each of BaO, La₂O₃ and CuO (10 wt.% each) to change its morphology and electrochemical catalytic activities. Then, the NOx sensing characteristics of mixed-potential-type YSM-based planar sensor were examined at temperatures of 500-800℃ by using each of the obtained NiO-based samples as a sensing electrode (SE). As a result, it was found that the CuO-added NiO-SE gave the large enhancement in NO₂ sensitivity as well as NO₂ selectivity at 800℃ even under wet condition, in comparison with the pure NiO-SE.

安定化ジルコニアを用いたプラナー型酸素センサ用酸化物系固体参照極材料

九大院総理工、^*九大産学連携センター

○中久保 昌平、 寺田 大将^*、 島本 洋一^*、 三浦 則雄^*

OXIDE-BASED SOLID REFERENCE-ELECTRODE FOR PLANAR OXYGEN SENSOR USING STABILIZED ZIRCONIA

Shohei NAKAKUBO, Daisuke TERADA^*, Yoichi SHIMAMOTO^* and Norio MIURA^*

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

In order to search a new material for solid reference-electrode to use in a planar oxygen-sensor based on stabilized zirconia (YSZ), the sensitivities to various gases for several mixed-oxide materials were examined. As a result, it was found that, among the oxides examined, only NiMn₂O₄ was insensitive to any of the examined various gases (NO₂, NO, H₂, C₃H₈, CH₄ and CO, 400 ppm each) in the temperature range of 400-900℃ and was independent of the change in oxygen concentration from 0.1 to 20 vol.% at 600℃. It was confirmed that the planar-type oxygen sensor using Pt sensing electrode (SE) and NiMn₂O₄ reference-electrode (RE) could be operated well as an oxygen sensor as well as an A/F sensor at 600℃.

固体電解質型水素センサの開発

新コスモス電機

○中里嘉浩，川端有香，前川亨，鈴木健吾

A SOLID ELECTROLYTE TYPE HYDROGEN GAS SENSOR USING YTTRIA STABILIZED ZIRCONIA

Yoshihiro NAKAZATO, Yuka KAWABATA, Toru MAEKAWA, Kengo SUZUKI

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

A solid electrolyte type hydrogen (H₂) gas sensor has been developed using yttria stabilized zirconia (YSZ), where platinum and gold were used as sensing electrode and counter electrode respectively. The sensing characteristic of the sensor was investigated by measuring H₂ and some of interference gases in a concentration range of 10-10000ppm. Moreover the dependency of the sensor on ambient temperature and humidity was also investigated. The sensor showed high sensitivity to H₂ and very low sensitivity to the interference gases. Furthermore the sensor was almost not influenced by the ambient temperature and humidity.

セラミックス高機能性電極による新規センサデバイスの構築

九工大工

○清水陽一

DESIGN OF NOVEL ELECTROCHEMICAL SENSOR DEVICE WITH CERAMIC FUNCTIONAL ELECTRODE

Youichi SHIMIZU

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

Sol-gel processing techniques of ceramic electrodes as well as solid-electrolytes were developed for designing new functional electrochemical environmental sensor devices. Solid-state sensors combined with solid electrolytes and ceramic electrodes have been investigated for the detection of NO_x, CO₂, and SO₂. New amperometric-, electrochromic-, and impedance metric- sensing techniques to environmental ion with high sensitivity and selectivity were developed by the use of ceramic-based electrodes. Anodic current of the ceramic thin-film- based electrode showed good properties of amperometric sensing to hydrogen-phosphate ion. Opto-electrochemical phosphate-ion sensors based on electrochromism of metal-oxide thin-film electrodes were developed. All solid-electrolyte ion sensor device using an Na-ion conductor as an impedance metric transducer and a perovskite-type oxide thin-film as a receptor, respectively, could be also demonstrated.

多等類固体フィルムを用いた光学湿度センサの検討

筑波学院大^a，茨城大理^b

○高藤　清美^a，後閑　寛彦^b，金子　正夫^b

STUDY OF HUMIDITY OPTICAL SENSOR USING POLYSACCHARIDE SOLID FILM

○Kiyomi TAKATO ^a , Norihiko GOKAN ^b and Masao KANEKO ^b

^a The Faculty of Information & Communication, Tsukuba Gakuin University, Tsukuba-shi, Ibaraki 305-0031
^b Faculty of Science, Ibaraki University, Mito-shi, Ibaraki 310-8512

This paper reports fabrication of a humidity optical sensor. Many of the conventional humidity sensors have utilized electric characteristics changes such as the change of conductivity or dielectric constant. The disadvantages of such humidity sensors can be overcome by using optical sensors, since the latter have many advantages; they do not use electric current, can be used even in a flammable vapor (antiexplosive), are stable under electromagnetic disturbance (such as in an electric oven), etc. In this investigation, fabrication and characterization of a humidity optical sensor are reported that incorporates Ru(bpy)₃²⁺ in a polysaccharide film coated on an end of an optical fiber. The present humidity optical sensor used a blue light emitting diode for excitation of luminescent probe (Ru(bpy)₃²⁺) and also a photodiode for the detection of the emission from the Ru(bpy)₃²⁺. The sensing characteristics will be reported.

酸素吸脱着処理をしたSnO₂単結晶(110)表面のSTM観察

^a　九州大学大学院総合理工学研究院
^b　九州大学大学院総合理工学府

○島ノ江憲剛^a、碇　和正^b、清水康之^b、山添　�f^a

STM OBSERVATION OF OXYGEN-ADSORBED SnO₂ (110) SURFACE BY THERMAL TREATMENT UNDER OXIDATIVE CONDITION

Kengo Shimanoe(a), Kazumasa Ikari(b), Yasuyuki Shimizu(b), Noboru Yamazoe(a)

(a) Faculty of Engineering Sciences, Kyushu University
6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580
(b) Interdisciplinary Graduate School of Engineering Sciences, Kyushu University
6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580

Surface structure of SnO₂ (110) treated thermally under oxidative condition was investigated by STM. After thermal treatment under oxidative condition, the [001]-oriented wide rows and dark spots beside the [001]-oriented fine rows were observed. Compared with the surface reduced by hydrogen, it is attributed the observed wide rows and dark spots to O₂^- (molecularity adsorption) and O^- (adsorption with negative charge), respectively.

分子ふるいシリカ被覆酸化スズセンサによる形状選択的検出

（鳥取大工^a、科技機構さきがけ^b）

○関山 昌宏^a、　片田 直伸^a,b、　丹羽 幹^a

SHAPE SELECTIVE DETECTION BY TIN OXIDE CHEMICAL SENSOR COATED WITH MOLECULAR SIEVING SILICA OVERLAYER

Masahiro ＳＥＫＩＹＡＭＡ ^a 、 Naonobu ＫＡＴＡＤＡ ^a,b and Miki ＮＩＷＡ ^a

^a Department of Materials Science, Faculty of Engineering, Tottori University, Koyama-cho, Tottori 680-0945, Japan
^b PRESTO, JST, Kawaguchi, Saitama 332-0012, Japan

In order to generate a novel shape selective function onto a semiconductor gas sensor, tin oxide surface was modified by chemical vapor deposition of silica using molecular template. Tin oxide powder was loaded on an alumina plate, and pretreated in an oxygen flow at 673 K. Then, benzaldehyde was adsorbed in a helium flow at 423 K, followed by the deposition of tetramethoxysilane at 473 K and calcination in an oxygen flow at 673 K. The sensitivities of thus modified SiO₂/SnO₂ sensor were measured to C₆H₁₄ isomers in an N₂/O₂ flow at 543 K. The unmodified SnO₂ sensor showed high sensitivities to all the tested C₆H₁₄ isomers (hexane, 2-methylpentane and 2,2-dimethylbutane) under the experimental conditions. The SiO₂/SnO₂ modified in the presence of benzaldehyde template showed no response to 2,2-dimethylbutane and a low sensitivity to 2-methylpentane, while the sensitivity to hexane was kept high. This indicates that the modified sensor detected the presence of two methyl branches with 100 % of the selectivity, based on the shape of cavity controlled by the template molecule.

ヘテロ積層半導体型ガスセンサのベンゼン感知特性

長大工

○森内誠治，兵頭健生，清水康博，江頭　誠

BENZENE SENSING PROPERTIES OF HETEROLAYERED SEMICONDUCTOR-TYPE GAS SENSORS

Seiji MORIUCHI, 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

Effects of noble metal loading and heterolayered structure on the benzene sensing properties of semiconductor-type sensors have been investigated. Although the benzene response of the sensors without noble metal loading was small, noble metal loading resulted in improvement of the response. Especially, the sensor fabricated with 10TiO₂-90ZnO loaded with 0.5 wt% Au (0.5Au/10TiO₂-90ZnO) showed the largest response among single layer sensors tested, when preparation procedure of 10TiO₂-90ZnO powder was carefully controlled. Stacking of a 0.5Pd/10TiO₂-90SnO₂ layer on the 0.5Au/10TiO₂-90ZnO sensing layer led to further improved response at temperatures lower than 300°C. The large improvement of the benzene response at lower temperatures is considered to arise from either one of the following two factors or by both: partial oxidation of benzene in the upper layer and limitation of oxygen gas diffusion into the underlying sensing layer by the upper layer.

パラジウム・マグネシウム合金薄膜を用いた水素センサ

産総研^a，松下電工^b，東北大^c

吉村和記^a、仲野純章^b、内梨　栄^b、山浦真一^c、木村久道^c、井上明久^c

HYDROGEN SENSOR USING Mg-Pd ALLOY THIN FILM

Kazuki YOSHIMURA^a, Sumiaki NAKANO^b, Sakae UCHINASHI^b, Shin-ichi YAMAURA^c, Hisamichi KIMURA^c, Akihisa INOUE^c

^aMaterials Research Institute for Sustainable Development, AIST, Nagoya, Aichi 463-8560, Japan
^bResearch & Development Center, Home Appliances Manufacturing Business Unit, Matsushita Electric Works, Ltd.,
Kadoma 571-8686, Japan
^cInstitute for Materials Research, Tohoku University, Sendai 980-8577,Japan

Pd-capped Mg-Pd alloy thin films were prepared by DC magnetron sputtering using Mg and Pd targets, and their hydrogen sensing characteristics have been investigated. After exposure to hydrogen containing atmosphere, the resistance of the film increases by the formation of insulating hydride in the film. By monitoring the resistance of Pd/Mg-Pd thin film, we can get the information on hydrogen concentration. Pd-capped MgPd0.1 film with the thicknesses of 4 nm Pd and 20 nm MgPd0.1 shows a good hydrogen sensing property for 4 vol.% hydrogen in Ar. With increase of Pd content in alloy composition of Mg-Pd thin film, the modulation range of resistance decreases, although the recovery process is getting faster. Their sensing range is from 0.01% to 10% hydrogen in Ar. These films are supposed to be one of candidates for a low-cost room temperature hdrogen sensor.

ナノギャップ電極を持つWO₃ナノセンサのNO₂検知特性に及ぼす膜厚の効果

立命館大理工

○大河内　侑、小椋俊介、小西　聡、玉置　純

EFFECT OF FILM THICKNESS ON NO₂ SENSING PROPERTIES OF WO₃ NANO-SENSORS WITH NANO-GAP ELECTRODE

Yu Okochi, Shunsuke Ogura^*, 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

Effects of film thickness on NO₂ sensing properties have been investigated for WO₃ nanosensors with nano-gap electrode. The nano-gap electrodes with gap-size of 100 nm was fabricated on SiO₂/Si substrate by MEMS techniques (photolithography and FIB). Then the WO₃ film was deposited on the nano-gap electrode by suspension dropping to be nano-gas sensor. The sensing properties to dilute NO₂ of WO₃ film nanosensors were measured in the range of 0.01-1 ppm at 200 ℃. The film thickness was changed from very thin state (nano-gap electrodes was visible) to very thick one (100 μm). The sensitivity increased with increasing film thickness up to 12-18 μm. The sensitivity had a maximum at this thickness and then decreased after this. As discussed previously [2], it is considered that the sensitivity is influenced by the diffusions of NO₂ molecules as well as O₂ molecules inside the WO₃ film.

実用型高感度マイクロNO₂センサの検知特性と環境モニタリングへの応用

立命館大理工^*、堀場製作所^**、エフアイエス^***

○高木　鉄平^*、中田　嘉昭^**、山岸　豊^**、松本　晋一^***、玉置　純^*

SENSING PROPERTY OF HIGH SENSITIVITY MICRO NO₂ GAS SENSOR AND ITS APPLICATION TO ENVIRONMENTAL MONITORING

Teppei Takagi^*, Yoshiaki Nakata^**, Yutaka Yamagishi^**, Shinichi Matsumoto^***, Jun Tamaki^*

^*Department of Applied Chemistry, Faculty of Science and Engineering,
Ritsumeikan University, Kusatsu-shi, Shiga 525-8577
^** R&D Center, HORIBA Ltd., Minami-ku, Kyoto 601-8510
^*** Sales Engineering Division 1, FIS Inc., Itami-shi, Hyogo 664-0891

A prototype WO₃ thick film microsensor has been fabricated for highly sensitive detection of dilute NO₂. The sensor substrate equipped with Au comb-type microelectrode and W thin film heater was fabricated by means of MEMS techniques. The WO₃ thick film was deposited on the Au microelectrode to be microsensor. The Au comb-type microelectrode (line width: 5 μm, dist ance between lines: 5 μm) was designed in an area of 1x1 mm² and the homog eneous temperature distribution was achieved due to specific heater pattern. The WO₃ thick film microsensor showed extremely high sensitivity to dilute NO₂ (S = 43 to 0.02 ppm NO₂) at heater voltage of 13V (240℃). It was found that the WO₃ microsensor could be applied for the environmental NO₂ monitoring.

電界効果トランジスタNO₂センサを用いた動態計測システムの検討

九大院総理工

○西依伸洋(a)、島ノ江憲剛(b)、山添　�f(b)

DESIGN OF ON-SITE MONITORING SYSTEM USING FIELD EFFECT TRANSISTOR TYPE NO₂ SENSOR

Nobuhiro NISHIYORI(a), Kengo SHIMANOE(b), Noboru YAMAZOE(b)

(a)Interdisciplinary Graduate School of Engineering Sciences, Kyushu University
6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580
(b)Faculty of Engineering Sciences, Kyushu University
6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580

In order to fabricate compact on-site monitoring system, FET type NO₂ sensor attached with an NaNO₂-WO₃ auxiliary phase was
investigated under various measurement conditions for influences by working temperature and gas flow rate, wake-up properties,
repeatability and long term stability. As a result, it was found that the FET sensor temperature-controlled by Pt heater with
diode showed excellent sensor properties. The compact monitoring system included the FET sensor was compared with
chemiluminescence type NOx analyzer. It turned out that the system operated at 150℃ indicated fairly good response and
recovery properties to NO2 in ppb level as well as the NOx analyzer.

To Japanese Contents To English Contents

火災早期発見のためのガスセンサシステムの開発

金沢工大^a，新コスモス電機^b，金沢星稜大^c

石榑大介^a、竹井義法^a、山ノ口　崇^a、南戸秀仁^a、笠原　浩^b、大藪多可志^c

DEVELOPMENT OF A GAS SENSOR SYSTEM FOR EARLY FIRE DETECTION

Daisuke ISHIGURE^a, Yoshinori TAKEI^a, Takashi YAMANOKUCHI^a, Hidehito NANTO^a, Hiroshi KASAHARA^b and Takashi OYABU^c

^aKanazawa Institute of Tech., Hakusan, Ishikawa 924-0838, Japan
^bNew Cosmos Electric Co., LTD, Osaka 532-0036, Japan
^cKanazawa Seiryou Univ., Kanazawa, Ishikawa 920-8620, Japan

This paper shows that we develop a system for early fire detection by using a gas sensor array. Several types of metal oxide semiconductor (MOS) gas sensors construct the sensing array. Each sensor on the array has different characteristics. It is generally known that ordinary fire alarm systems sense smoke and heat to detect fire. Therefore the detectors cannot detect initial stage of fire. Then we develop an odor sensing system for early fire detection by using commercially available MOS sensors. The proposed gas sensing system is consisted of five different types of sensors, te three sensors have wide sensitivity for various odors, and the others have high sensitivity for fydrogen. We show that the gas sensor array system can discriminate the targets involving the odorants obtained by burning several materials from the disturbances and the multivariate analysis can perform the discrimination of the odorants, which can reduce an influence of change of concentration of the gases.

To Japanese Contents To English Contents

新規電解液を用いた電気化学式COセンサ

フィガロ技研株式会社

○加藤　由起、藤森　裕樹、井上　智弘、松浦　吉展

A NEW RELIABLE ELECTROCHEMICAL CO GAS SENSOR USING A UNIQUE ELECTROLYTE

Yuki KATO， Yuki FUJIMORI，Tomohiro INOUE，Yoshinobu MATSUURA

Figaro Engineering Inc.,1-5-11 Senba-nishi,Mino,Osaka 562-8505,Japan

By using a newly low concentration neutralized aqueous organic sulfonic acid resin as an electrolyte, integration of an extremely small amount of noble metal catalyst into the catalyst layer, and application of a separator, this new electrochemical sensor has the advantage of being more environmentally friendly than traditional electrochemical sensors. Using a dry battery structure, the developed sensor poses no risk of electrolyte leakage and offers characteristics which can detect CO gas in various temperature range (-40 to 70°C) and display high durability and long term stability.

デカンチオール修飾金および銀ナノ粒子のインピーダンス解析による有機ガスの検出

熊本大工

楠田秀明、冨永昌人、谷口　功

DETECTION OF ORGANIC VAPOR BY IMPEDANCE ANALYSIS AT AU AND AG NANOPARTICLES CAPPED WITH DECANETHIOL MONOLAYER

Hideaki KUSUDA, Masato TOMINAGA and Isao TANIGUCHI

Department of Applied Chemistry and Biochemistry, Kumamoto University
2-39-1, Kurokami, Kumamoto 860-8555, Japan

Properties of metal nanoparticles are determined by particle size, shape and crystal structure. Nanoparticles might have special property for bulk metal not to have. The tunable electronic properties of nanoparticle-structured materials has recently been increasingly interested in because of applications to sensing and catalysis. In this work, we report the detection of volatile organic compounds and water by measuring on impedance at interdigitated microelectrodes (IME) with Au and Ag nanoparticles which have decanethiol shell. Impedance response for exposure to water, ethanol or toluene, impedance decreased, while for hexane, an increase in impedance was observed at IME with these nanoparticles.

吸着燃焼式ガスセンサ材料表面での有機ガスの吸着燃焼特性

長大工(a)、矢崎総業(b)

○柴田浩希(a)、兵頭健生(a)、笹原隆彦(b)、清水康博(a)、江頭　誠(a)

ADSORPTION AND COMBUSTION BEHAVIOR OF ORGANIC COMPOUNDS ON SENSOR MATERIALS USED FOR ADSORPTION/COMBUSTION-TYPE SENSORS

Hiroki SHIBATA(a), Takeo HYODO(a), Takahiko SASAHARA(b), Yasuhiro SHIMIZU(a) and Makoto EGASHIRA(a)

(a) Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University, 1-14 Bunkyo-machi,
Nagasaki 852-8521, Japan
(b) Technology Center, Yazaki Corporation, 1500 Mishuku, Susono, Shizuoka 410-1194, Japan

The origin of unique response transients of an adsorption/combustion-type sensor to organic compounds has been investigated from the view points of their adsorption/ desorption properties on and from Pd/γ-Al₂O₃ and γ-Al₂O₃ used as a sensing and a reference layer, respectively. Temperature programmed desorption (TPD) technique revealed that Pd/γ-Al₂O₃ was more active than γ-Al₂O₃ for the complete oxidation of organic compounds. Desorption gases resulting from the combustion varied with the kind of organic compounds adsorbed and also depended on the molecule structure of the isomers. For each target gas, the shape of the TPD spectra of CO₂ from Pd/γ-Al₂O₃ was found to be similar to the differential profile of the response transient of the sensor up to a preset temperature 450゜C. Thus, the sensor response well reflects the heat generated during the complete combustion of organic compounds preadsorbed on the Pd/γ-Al₂O₃ sensing layer.

10mol%ハフニアドープセリアを使った抵抗型酸素センサの作製

産総研

○伊豆典哉、申ウソク、松原一郎、村山宣光

FABRICATION OF RESISTIVE OXYGEN SENSOR BASED ON 10 MOL% HAFNIA DOPED CERIA

Noriya IZU, Woosuck SHIN, Ichiro MATSUBARA, Norimitsu MURAYAMA

National Institute of Advanced Industrial Science and Technology (AIST)
2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya, Aichi 463-8569

In order to simplify an electric circuit for a resistive oxygen gas sensor, resistance of the resistive oxygen sensor needs to become small. It was reported that the resistance of the sensor using Zr-doped ceria was smaller than that using non-doped ceria. In this study, the resistive oxygen sensor using thick film of ceria doped with Hf which is the same group of the periodic table as Zr (Ce_0.9Hf_0.1O₂ sensor) was fabricated and the sensor property of it was investigated. Ce_0.9Hf_0.1O₂ thick film had single fluorite phase. The thick film had porous structure with 1-2 micrometer particles. Ce_0.9Hf_0.1O₂ sensor had much lower resistance than the sensors using Ce_0.9Zr_0.1O₂ thick film and CeO₂ thick film. The temperature dependence of resistance of Ce_0.9Hf_0.1O₂ sensor was smaller than that of Ce_0.9Zr_0.1O₂ sensor and CeO₂ sensor.