Vol. 17, Supplement A (2001)

Proceedings of the 32nd Chemical Sensor Symposium
April 1-3, 2001

Abstracts

1.

ŠgŽU•û’öŽ®‚ÉŠî‚­”––ŒŒ^”¼“±‘̃KƒXƒZƒ“ƒT‚̉ðÍi‚Pj’è튴“x‹““®

Žðˆä@„A¼‰i’¼Ž÷A“‡ƒm]Œ›„AŽR“Y@úf

‹ã‘å‰@‘‡—H

DIFFUSION EQUATION-BASED STUDY OF THIN FILM TYPE SEMICONDUCTOR GAS SENSOR (1) SENSITIVITY BEHAVIOR UNDER STEADY STATE

Go SAKAI, Naoki MATSUNAGA*, Kengo SHIMANOE, Noboru YAMAZOE

Faculty of Engineering Sciences, Kyushu University
*Department of Molecular and Material Sciences, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan

Diffusion equation-based analysis was performed to understand the sensitivity behavior of thin film type semiconductor gas sensor. The diffusion equation was formulated by assuming that an inflammable gas, which moves inside the film by Knudsen diffusion, reacts with adsorbed oxygen following a first order reaction kinetic. The gas concentration profile derived reveals that the depth of gas penetration inside the film depends strongly on diffusivity and reactivity of the gas in problem. The profile allows one to estimate the gas sensitivity of the film if its sheet conductance is specifically correlated with the gas concentration. By assuming that the correlation be linear, the observed dependence of gas sensitivity on the film thickness could be simulated satisfactorily. The volcano-shaped sensitivity vs. temperature correlation could also be accounted for by considering the temperature dependence of diffusion coefficient (DK), reaction rate constant (k) and sensitivity coefficient (a).

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2.

ŠgŽU•û’öŽ®‚ÉŠî‚­”––ŒŒ^”¼“±‘̃KƒXƒZƒ“ƒT‚̉ðÍi2j‰ß“n‰ž“š‹““®

¼‰i’¼Ž÷AŽðˆä@„A“‡ƒm]Œ›„AŽR“Y@úf

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DIFFUSION EQUATION-BASED STUDY OF THIN FILM SEMICONDUCTOR GAS SENSOR (2) RESPONSE TRANSIENT

Naoki MATSUNAGA, Go SAKAI*, Kengo SHIMANOE* and Noboru YAMAZOE*

Department of Molecular and Material Sciences, Graduate School of Engineering Sciences, Kyushu University
*Faculty of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan

A diffusion equation has been solved under non-steady condition in order to simulate how the concentration profile of a target gas develops inside a thin film semiconductor gas sensor after the flow of target gas is brought into contact with the sensor at time 0. The diffusion equation as well as the other boundary conditions are assumed to be the same as those previously used for the steady state analysis. The solution is expressed by a polynomial function involving diffusion coefficient (D), rate constant (k), film thickness (L), depth from the film surface (x), time (t) and target gas concentration outside (Cs). Remarkably the gas concentration transient exhibits overshooting behavior before reaching a steady value, the magnitude and appearance time of the overshooting being very dependent on D, k and L. It follows that an overshooting phenomenon in sensor response can also be expected to show up under particular conditions for D, k and L.

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3.

Ž_‰»ƒCƒ“ƒWƒEƒ€Œn”––ŒƒZƒ“ƒT‚Ì’á”Z“x‰–‘fƒKƒXŒŸ’m“Á«

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—§–½ŠÙ‘å—H

SENSING PROPERTIERS TO DILUTE CHLORINE GAS OF INDIUM OXIDE-BASED THIN FILM SENSORS

Jun TAMAKI, Eijiro NISHIMURA, Chizuko NARUO, Yoshifumi YAMAMOTO, and Masao MATSUOKA

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

IIndium oxide based thin films were prepared by EB evaporation as well as dropping method and subjected to the detection of dilute chlorine gas at 200-500 Ž. The In2O3 evaporated film showed complicated response to Cl2 ga s. On the other hand, the In2O3 thin film prepared by dropping method, in which In2O3 powder calcined at 850 Ž was used, exhibited simple response ch aracteristics and the sensitivity as high as 2500 to 5 ppm Cl2 at 250 Ž. T his sensor also could detect dilute Cl2 gas until 0.02 ppm. The response characteristics were interpleted by several adsorptions of Cl2 on In2O3 surface.

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4.

DILUTE CH3SH-SENSING CHARACTERISTICS OF CdGa2O4 FILM PREPARED BY SOL-GEL METHOD

Xiangfeng CHU and Jun TAMAKI

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

The thick films of CdGa2O4, CdFe2O4, CdIn2O4 and Cd2Sb2O7 were prepared on the silicon substrates equipped with Au comb-type electrodes. The phase constituents and microstructure of the films were characterized by means of XRD and SEM, and the gas-sensing properties to dilute volatile sulfides were studied. The experiments illustrated that CdGa2O4 thick films had very high sensitivity and good selectivity to dilute CH3SH at 300 Ž.

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5.

Pd/—z‹ÉŽ_‰»TiO2–Œ‚Ì…‘fƒKƒXŒŸ’m“Á«
´…N”ŽAŒK–ì’¼Ž÷A•º“ªŒ’¶A]“ª@½

’·è‘åH

H2 GAS SENSING PROPERTIES OF Pd/ANODICALLY OXIDIZED TiO2 FILM

Yasuhiro SHIMIZU, Naoki KUWANO, Takeo HYODO, and Makoto EGASHIRA

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

TiO2 films were prepared by anodic or atmospheric air oxidation of Ti metal, and the H2 sensing properties of the junction-type sensors of the films and Pd metal have been investigated at 250 - 500‹C under reverse and forward bias conditions. A TiO2 film (A-TiO2) oxidized anodically in a H2SO4 solution had nano-holes of 50-130 nm in diameter and exhibited the highest H2 sensitivity among the films tested, especially under reverse bias conditions. A-TiO2 was less sensitive to CO, but its H2 sensitivity was decreased by the coexistence of water vapor. Water vapor was suggested to reduce the reaction between H2 and oxygen adsorbates on TiO2, and/or the dissociative dissolution of H2 into Pd and/or affecting the potential barrier at the interface between TiO2 and Pd of the junction-type or diode-type sensor.

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6.

”M“I‚ɈÀ’è‚ȃƒ\ƒ|[ƒ‰ƒXŽ_‰»ƒXƒY‚Ì’²»‚ƃZƒ“ƒTÞ—¿‚ւ̉ž—p

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’·è‘åH

PREPARATION OF THERMALLY STABLE MESOPOROUS SnO2 POWDER AND APPLICATION TO SENSOR MATERIAL

Takeo HYODO, Norihiro NISHIDA, Yasuhiro SHIMIZU and Makoto EGASHIRA

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

Ordered mesoporous SnO2 powders with thermal stability were prepared from sodium stannate by utilizing the self-assembly of n-cetylpyridinium chloride, followed by treatment with phosphoric acid (PA). It was found that PA-treatment was indispensable for preparing the thermally stable mesoporous SnO2; it reduced the growth of SnO2 crystallites. TEM photographs revealed the ordered layer structure of mesoporous SnO2 calcined at 600Ž for 5 h in almost all regions even after the calcination. It was also confirmed that the mesoporous SnO2 had a large pore volume at a pore diameter of ca. 1.6 nm with a large surface area of 305 m2 g-1. The sensitivity to 500 ppm H2 and 500 ppm CO of a thick film-type sensor (ca. 85 mm thick) fabricated with the mesoporous SnO2 were 22.9 at 350Ž and 3.72 at 450Ž, respectively.

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“Á•Êu‰‰

”––ŒE”÷׉ÁH‹Zp‚Ɖ»ŠwƒZƒ“ƒT‚ւ̉ž—p

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(Š”)–L“c’†‰›Œ¤‹†Š@“dŽqƒfƒoƒCƒX•”

THIN FILM & MICROMACHINING TECHNOLOGIES FOR CHEMICAL SENSORS

Jiro SAKATA

Electronics Device Lab., Toyota Central Res. & Dev. Labs., Inc.
Nagakute, Aichi, 480-1192, Japan

Development of fabrication technology for micro-sensors gives us small, low energy consumption, and low cost chemical sensor devices. This paper describes the factors of realizing micro-chemical sensors. Thermal isolation properties are one of the most important factors, because gas sensors are usually operated at high temperature. The sensors fabricated by the surface micro-machining make energy consumption reduced to 1/100, and show an excellent response for heating. Fabrication process of sensing materials is also important. @Solid electrolyte thin films, such as oxygen ion and proton conductor, can be deposited by sputtering. Limiting current-type micro-sensors can be fabricated by the deposition of solid electrolyte thin films on porous substrates, and show excellent sensitivity and linearity for oxygen or hydrocarbon concentration.

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7.

–F‘°Œn VOCŒŸo—p”÷¬•ªŒõƒtƒ[ƒZƒ‹‚Ì컂Ƃ»‚Ì“Á«

–x“à@•×AX–{@FAã–ì@—SŽqA’O‰H@C

NTT¶ŠˆŠÂ‹«Œ¤‹†Š

FABRICATION AND CHARACTERISTICS OF A MICRO-FLUIDIC DEVICE FOR OPTICAL DETECTION OF AROMATIC VOC

Tsutomu HORIUCHI, Takashi MORIMOTO, Yuko UENO, Osamu NIWA

NTT Lifestyle and Environmental Technology Laboratories, Nippon Telegraph and Telephone Corporation
Atsugi, Kanagawa 243-0198, Japan

We fabricated a prototype micro-fluidic device to detect and identify atmospheric levels of aromatic VOCs by using absorption spectroscopy as the detection method. The device consists of concentration- and detection-cells. Both cells are fabricated using a micro machine technique. The concentration-cell is composed of an adsorbent to concentrate VOC gases and a thin-film heater to desorb the concentrated gas thermally. The concentration-cell could amplify the detection signal of toluene gas by two orders of magnitude. We successfully measured ppm-levels of toluene gas with this device.

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8.

Wω»‚u‚n‚bƒZƒ“ƒT‚Ì‚Š´“x‰»

Špè‰ë”ŽA’J–쎖¤A—´ŽR’qžÄA¬XˆêÆA’JŒû^–ç


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IMPROVEMENT IN VOC SENSITIVITY OF INTEGRATED SEMICONDUCTOR GAS SENSORS

Masahiro KADOSAKI, Katsumi TANINO, Chiei TATSUYAMA*, Kazuya KOMORI** and Shinya TANIGUCHI***

Toyama Industorial Technology Centor, 383 Takada,Toyama 930-0866, Japan
*Faculty of Engineering, Toyama Univesity, 3190 Gofuku,Toyama 930-8555, Japan
**Hokuriku Electric Ind.Co.,Ltd., 3158 Shimo-okubo,osawano,Toyama 939-2292, Japan
***Cosel Co.,Ltd.., 1-6-43 Kamiakae,Toyama 930-0816, Japan

Sick-house syndrome receives much public attention as a problem of indoor environment at present. Volatile organic compounds (VOC) such as formaldehyde (HCHO) and xylene (C6H4(CH3)2) generated from building materials are pointed out as one of origins of the sick-house syndrome. Therefore, the development of a sensor system available to measure the indoor-air pollution level in new houses at high sensitivity, easily and with low cost is highly desired. In our previous studies, we found that the polar plots of sensitivity obtained by an integrated gas sensor, which were composed of SnO2, WO3, In2O3, ZnO, Co3O4 and Cr2O3, are useful to discriminate chemical species in VOC. In order to detect ppb-level VOC gases, using the polar plots of the integrated sensor, the present study was carried out for the improvement of the sensitivities of WO3 and In2O3 sensors which were high sensitive materials to xylene and etyl acetate (CH3COOC2H5), respectively. Among the 31 additives, the effective materials for WO3 sensors were Cs, Rb, Ta2O5 and Nb2O5, also, those for In2O3 sensors were MnO2 and Pt.

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9.

Pt^WO3–Œ‚ð—p‚¢‚½í‰·“®ìŒ^…‘fƒZƒ“ƒT

ŽR–{ØXŽqA‰ªèTŽiA’†ì‰pŒ³A’©‘qjŽ¡

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A CHEMORESISTOR-TYPE HYDROGEN GAS SENSOR USING Pt/WO3 THIN FILM

Nanako YAMAMOTO, Sinji OKAZAKI, Hidemoto NAKAGAWA, and Syukuji ASAKURA

Department of Materials Science and Chemical Engineering , Yokohama National University
Tokiwadai 79-5 Hodogayaku, Yokohama, Japan

Development of a chemoresistor-type hydrogen gas sensor using Pt/WO3 thin film was tried and characterized. In the presence of hydrogen gas, impedance of Pt/WO3 thin film prepared with sol-gel method was sharply decreased. It was indicated that tungsten bronze which is good conductor was formed by the reaction of hydrogen with tungsten trioxide. Up to 1 vol.%, the changes in impedance were proportional to hydrogen gas concentration. Fast response to hydrogen gas was observed. The recovery rate of the sensor was very slow and influenced by the concentration of oxygen gas. Furthermore, the reaction process was almost irreversible in absence of oxygen.

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10.

ƒpƒCƒƒNƒƒAŒ^Ž_‰»•¨”––Œ‚ð—p‚¢‚½NOxƒZƒ“ƒT

´…—zˆêA’†–ì—TOAŽO‰Y‘¥—Y*

‹ãH‘åHA‹ã‘åæ’[ƒZƒ“ƒ^[*

PYROCHLORE-TYPE OXIDE BASED THIN-FILM NOx SENSOR

Youichi SHIMIZU, Yasuhiro NAKANO, and Norio MIURA*

Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology
1-1 Sensui-cho, Tobata, Kitakyushu-shi, Fukuoka 804-8550, Japan
*Advanced Science and Technology Center for Cooperative Research, Kyushu Un iversity
6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan

Pyrochlore-type oxide based devices have been investigated for the detection of NO and NO2 in the range 10-1000ppm at 200-400Ž. Among the oxides tested , Bi2Ir2O7 - or Pb2Ru1.7Sb0.3O7-z-based devices were found to show highest s ensitivity to NO at 400Ž or NO2 at 200Ž, respectively. Pyrochlore-type ox ide thin-films could be prepared by a sol-gel method using a metal-acetylace tone - poly(vinyl alcohol)(PVA) polymeric precursor method at 600Ž. A Pb2 Ru1.5Pb0.5O7-z thin-film device prepared by the sol-gel method showed highly sensitive and selective NO sensing properties at 400Ž. The 90% response tim e to 200ppm NO of the thin-film device was short as ca. 30s at 400Ž.

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11.

ƒfƒBƒbƒv–@‚ð—p‚¢‚½ƒIƒ]ƒ“ƒZƒ“ƒT‚ÌŠJ”­

“cOŽjA’†“‡LÆA•ž•”Í—Ç*A‹g’rMK*

ƒGƒtƒAƒCƒGƒXA¼‰º“dŠíŽY‹Æ ‚­‚炵ŠÂ‹«ŠJ”­C*

DEVELOPMENT OF OZONE SENSOR USING A DIP COATING METHOD

Hiroshi Koda, Hiroya Nakajima, Akiyoshi Hattori and Nobuyuki Yoshiike

FIS Inc.
3-36-3 Kitazono, Itami, Hyogo 664-0891, Japan
*Matsushita Electric Industrial Co., Ltd.,
3-1-1, Yagumo-Nakamachi, Moriguchi, Osaka 570-8501, Japan

We have developed a new metal oxide ozone sensor using the ITO (Tin doped Indium Oxide) thin film for gas sensing material. We have studied the application of a dip coating method for forming a characterised thin film layer, and found that this method is advantageous in achieving high controlability and productivity without any complicated systems. We have succeeded to develop a reliable and low cost sensor with high sensitivity, high selectivity and quick response speed. This sensor is capable in detecting ozone from 10 ppb level. This achievement provides an important breakthrough in ozone detection for a wide application in industrial, commercial and domestic fields.

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12.

Ž_‰»ƒXƒYŒnCOƒKƒXƒZƒ“ƒT‚É‚¨‚¯‚é‘fŽq•\–ʉüŽ¿‚̃ƒJƒjƒYƒ€iIj

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SURFACE MODIFICATION MECHANISM OF SnO2-BASED CO GAS SENSORS, iIj

Masatsugu MORIMITSU, Yuko NAGANO, and Morio MATSUNAGA

Department of Applied Chemistry, Kyushu Institute of Technology, Tobata, Kitakyushu 804-8550, Japan

The surface modification of SnO2-based CO gas sensor with sulfuric acid solutions reduces the sensor resistances in air and in CO, resulting in the enhancement of CO sensitivity. The mechanism of the surface modification was discussed with the comparison between modified and unmodified sensor surfaces by using XPS and FTIR. The results indicated that sulfate species existed on the modified sensor surface, and surface hydroxyl groups increased after the modification, the latter of which is possible to decrease in the sensor resistance in air. The reason for the enhancement of CO sensitivity was tried to explain by the effects of surface hydroxyl groups on the adsorption reaction of CO.

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13.

ŽÀŒ±ŽºŠÂ‹«‚É‚¨‚¯‚é‚•ªŽq•¡‡–ŒCO2ƒZƒ“ƒT‚Ì’·ŠúŠÔì“®“Á«‚Æ‹¤‘¶ƒKƒX‚̉e‹¿

‘å•ä—²”ŽC’Å–Ø@OCŠOè@„C¬‘q‹»‘¾˜Y

ŽRŒû‘åH

PROPERTY OF A CO2 SENSOR WITH POLYMER COMPOSITE OPERATING FOR A LONG-TERM IN LABORATORY AND EFFECT OF EXISTING GASES ON THE SENSITIVITY FOR CO2

Takahiro OHO, Hiroshi SHIIGI, Tsuyoshi TONOSAKI, Kotaro OGURA

Faculty of Engineering, Department of Applied Chemistry, Yamaguchi University
Tokiwadai, Ube 755-8611, Japan

The composite film consisting of base-type polyaniline (PAn) and poly(vinyl alcohol) (PVA) responds to CO2 at room temperature, and the log of electrical resistance is linearly related with the log of CO2 concentration in a wide range from 100 ppm to 100 % at 30 %RH. The decrease in resistance of the composite film with an increase of CO2 concentration is attributed to the transformation of the base-type PAn to the salt-type, which is caused by the incorporation of hydrogen carbonate ions formed by the hydrolysis of CO2 into the base-type PAn. In the present report, the property of a CO2 sensor with polymer composite operating for a long term and the effect of existing gases such as O2, alcohols, HCHO, HCl, N2O, NO2 and NH3, which are often detected in a chemistry laboratory, on the sensitivity for CO2 have been investigated.

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14.

ŠÏ—tA•¨‚Ì‘å‹C’†ƒKƒ\ƒŠƒ“‚Ìò‰»“Á«

‘å–÷‘½‰ÂŽu@ ¬–쎛•@ ‰Á“¡~@ “ìŒËGm@ ’|’†KŽO˜Y

‹à‘òŒoÏ‘å ‹ãB‘åEH ‹à‘òŒoÏ‘å ‹à‘òH‘å@ ’|’†’뉀—Ή»

PURIFICATION CHARACTERISTICS OF GOLDEN POTHOS FOR ATMOSPHERIC GASOLINE

Takashi Oyabu1, Takeshi Onodera2, Atsushi KATO1, Hidehito NANTO3 and Kozabro TAKENAKA4

1 Kanazawa University of Economics, Kanazawa 920-8620, Japan
2 Department of Electrical and Electronic Systems Engineering, Kyusyu University, Fukuoka 812-8581, Japan
3 Kanazawa Institute of Technology, Matto924-0838, Japan
4 Takenaka Garden Afforestation, Hakozaki, Nihonbashi, Edogawa 103-0015, Japan

Previous studies have shown that plants have the ability to purify various atmospheric chemicals. Gasoline is one of the more serious pollutants. Soil and atmospheric pollution caused by gasoline is increasing due to the spread of automobiles. In this paper, the purification characteristic of pothos plant for atmospheric gasoline is investigated using a tin oxide gas sensor. As for the results, the purification rate (Pr), which means the purification ability per hour indicated by a differential coefficient, has a maximum value at a longer lapse of time as the pollutant concentration becomes higher. Pr can be indicated by an exponential function of lapsed time. The Pr characteristic in soil also has a similar feature. A golden pothos plant growing in a pot of 30 cm in diameter is put in an experimental chamber of 300 liters to examine its purification ability. Pr had a maximum value after 40 hours from the time when 0.04 ml of gasoline was injected into the chamber.! Another value, which indicates total purification ability (Pa), is also adopted in this study. Pa can be derived using the peak value(h) and the full-width (tw) at half maximum of the tin oxide gas-sensor characteristic, namely Pa=h/tw~100. The Pa of the pothos for gasoline was about 7 and the value becomes smaller as the pollutant concentration becomes higher.

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15.

Na+ƒCƒIƒ““`“±‘Ì‚ð—p‚¢‚½Cl2ƒKƒXƒZƒ“ƒT‚É‚¨‚¯‚鎼“x‚̉e‹¿

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ˆ¤•Q‘åH

INFLUENCE OF HUMIDITY FOR Cl2 GAS SENSOR USING A Na+ IONIC CONDUCTOR

Hiromichi AONO and Yoshihiko SADAOKA

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

Influence of humidity in test gas for low Cl2 gas concentration region was investigated for a Cl2 gas sensor using a Na+ conductor. In the case of dry Cl2 gas using cold H2O trap, the n value was 1.86 which was very close to theoretical value n=2.0. However, the n value decreased to 1.50 if the H2O trap don't use for the measuring gas, because Cl2 gas reacted at 450 oC with H2O which contained in gas tank as an impurity. The EMF was strongly decreased when water vapor mixed to the Cl2 measuring gas. The experimental n value of ca. 0.9 agreed with the theoretical n=1.0 for humid atmosphere. The electromotive force (EMF) value in humid condition for a presented sensor probe can detect Cl2 gas concentration when we already knows the relative humidity. The response time was very similar for dry and humid conditions. The two step reaction on the electrode was suggested for humid condition.

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16.

ˆÀ’艻ƒWƒ‹ƒRƒjƒA‚ÆZnFe2O4“d‹É‚ð—p‚¢‚½‚‰·ì“®NOxƒZƒ“ƒT

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HIGH TEMPERATURE NOx SENSOR USING STABILIZED ZIRCONIA AND ZnFe2O4 SENSING ELECTRODE

Serge ZHUIYKOV, Midori MUTA, Takashi ONO, Akira KUNIMOTO, Noboru YAMAZOE, Norio MIURA

Advanced Science and Technology Center for Cooperative Research, KYUSHU UNIVERSITY
Kasuga-shi, Fukuoka 816-8580, Japan

A tubular sensor using yttria-stabilized zirconia (YSZ) and the spinel-type oxide sensing-electrode (SE) was fabricated and examined for NOx detection at high temperatures. Among spinel-type oxides tested and reported to date, ZnFe2O4 was found to give the highest sensitivity to NO2 in air at temperatures of 550-700Ž. In this temperature range, the EMF response of the sensor was almost linear to the logarithm of NO or NO2 concentration in the range from 25 ppm to 436 ppm. Investigation of the sensor stability showed that the output EMF to 100 ppm NO2 did not change substantially during 3 months after 20 days operation at 700Ž. The sensing mechanism of the sensor was discussed on the basis of the TPD data for oxides examined.

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17.

Na+“±“d‘Ì‚ð—p‚¢‚½“d—¬ŒŸoŒ^NOxƒZƒ“ƒT‚ÌŒŸ’m‹É”½‰ž‚ɂ‚¢‚Ä‚ÌŒŸ“¢

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‹ã‘å‰@‘—HA‹ã‘åæ’[ƒZƒ“ƒ^[*

SENSING ELECTRODE REACTION KINETICS OF AMPEROMETRIC NOx SENSOR USDING Na+ CONDUCTOR

Masaki ONO, Shinsuke HAYAHARA, Kengo SHIMANOE, Norio MIURA* and Noboru YAMAZOE

Department of Molecular and Material Sciences, Graduate School of Engineering Sciences, Kyushu University
*Advanced Science and Technology Center for Cooperative Research, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan

The reaction kinetics of the amperometric NOx sensor using Na+ conductor was investigated. As already reported, the response current to NO2 (up to 1 ppm) was linear to NO2 concentration when the sensing electrode was polarized at -150 mV versus the reference electrode at 150Ž, suggesting that the rate-determining step would be the mass transfer of NO2 to the three phase boundary (gas/electrode/NASICON) of the sensing electrode. First, a conventional case where the mass transfer in gas phase by molecular or Knudsen diffusion determines the rate was considered. However, the temperature dependence of the response current separately observed was not consistent with such gas diffusion-controlled mechanisms. Instead the temperature dependence could be explained fairly consistently by assuming that the rate be determined by the surface diffusion of adsorbed NO2 on the sensing electrode.

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18.

“dŠEŒø‰Êƒgƒ‰ƒ“ƒWƒXƒ^NO2ƒZƒ“ƒT‚É‚¨‚¯‚鈟Ɏ_ƒiƒgƒŠƒEƒ€•â•‘Š ‚Ö‚Ì‘æ2¬•ª“Y‰ÁŒø‰Ê

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‹ã‘å‰@‘—H,*‹ã‘åæ’[ƒZƒ“ƒ^[

EFFECT OF THE ADDITIVE OF SECOND COMPONENTS TO THE NaNO2 AUXILIARY PHASE OF FIELD EFFECT TRANSISTOR NO2 SENSOR

Seiji NAKATA, Kengo SHIMANOE, Norio MIURA*, Noboru YAMAZOE

Department of Molecular and Materials Sciences, Graduate School of Engineering Sciences, Kyushu University
*Advanced Science and Technology Center for Cooperative Research, Kyushu University
Kasuga-shi, Fukuoka 816-8580, Japan

In an attempt to improve the lower detection limit of FET type NO2 sensor, Ca3(PO4)2 and WO3 were added separately to the NaNO2 auxiliary phase of the device. It was found that the both additives brought about significant improvements in the NO2 sensing characteristics. The device using NaNO2-Ca3(PO4)2 (10:1 in molar ratio) or NaNO2-WO3 (5:1) auxiliary phase was capable of detecting NO2 down to 50 ppb or 30 ppb at 150[C, respectively, while one using NaNO2 was down to 200 ppb. The 90% response time also decreased significantly with the addition of the second components. These effects of the additives were shown to be accompanied by the larger downward shifts of the gate-source voltage in air (air level) relative to that in the NO2-containing atmosphere.

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19.

‘½‰¿ƒCƒIƒ““`“±‘Ì‚ð•ê‘Ì‚Æ‚µ‚½’YŽ_ƒKƒXƒZƒ“ƒT

¡’†MlAãì«sA¬‘qͶA‘«—§‹á–ç

ã‘å‰@H

CARBON DIOXIDE GAS SENSOR BASED ON MULTIVALENT ION CONDUCTING SOLID ELECTROLYTES

Nobuhito IMANAKA , Masayuki KAMIKAWA , Akio OGURA and Gin-ya ADACHI

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

A compact carbon dioxide gas sensor was fabricated by using the combination of neodymium oxide carbonate solid solution that is insoluble in water with Mg2+ ion conducting Mg(Zr0.85Nb0.15)4(PO4), and oxide anion conducting La0.9Sr0.1Ga0.9Mg0.1O3 solid electrolytes. The time necessary to attain a 90% response for the CO2 detection was less than several min. The sensor output was exactly consistent with the Nernst relation and a 1:1 linear relationship was obtained between the sensor output and the logarithm of the CO2 gas concentration. The influence of water vapor and liquid water dew on the sensor output was not observed. A quantitative CO2 gas detection was successfully realised with a rapid, continuous, and reproducible response.

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20.

ƒvƒƒgƒ““±“d‘Ì‚ðŽg—p‚µ‚½¬¬“dˆÊŒ^’Y‰»…‘fƒZƒ“ƒT

X@Œ«‘¾˜YA“ú”ä–ì‚Žm*A‹´–{’Žq*A²–ì@[

–¼‘å‰@lîE–¼HŒ¤*

A MIXED-POTENTIAL HYDROCARBON SENSOR USIGN A SrCe0.95Yb0.05O3-ƒ¿ ELECTROLYTE WITH A Pt ELECTRODE

Ken-taro MORI, Takashi HIBINO*, Atsuko HASHIMOTO* and Mitsuru SANO

Graduate School of Human Informatics, Nagoya University
Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
*National Industrial Research Institute of Nagoya
Hirate-cho, Kita-ku, Nagoya 462-8510, Japan

Mixed-potential type sensors using different ion conducting electrolytes with a Pt working electrode have been fabricated to investigate a relationship between the sensing properties for hydrocarbons and ion conduction in the electrolyte under oxidizing conditions at 600 Ž. There was an increase in the mixed potential for propene with increasing proton conduction or decreasing oxide ion conduction. The sensor using a SrCe0.95Yb0.05O3-ƒ¿ electrolyte showed an enhanced mixed potential for C1- C4 hydrocarbons by increasing the carbon number, unsaturating the C-C linkage, and branching the chain structure. In addition, this sensor barely showed the mixed potential for hydrogen, carbon monoxide, and nitrogen monoxide.

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21.

ƒAƒ|y‘fŠˆ«‰»–@‚É‚æ‚鈟‰”(II)ƒCƒIƒ“‚̃tƒ[ƒCƒ“ƒWƒFƒNƒVƒ‡ƒ“”÷—ÊŒv‘ª \ƒT[ƒ‚ƒŠƒVƒ“ƒJƒ‰ƒ€‚Ì“K—p\

²“¡¶’jEÎ_„E¬–ö´‰ÄE”Ñ“c‘×L

_“ÞìH‰È‘åŠwE‰ž—p‰»Šw‰È

FLOW-INJECTION MICRODETERMINATION OF ZINC(II) IONS BASED ON AN APOENZYME REACTIVATION METHOD \APPLICATION OF A THERMOLYSIN COLUMN\

Ikuo SATOH, Tsuyoshi ISHIGAMI, Sayaka OYANAGI, and Yasuhiro IIDA

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

TThe apoenzyme reactivation methods were applied to a thermolysin column for microdetermination of zinc(II) ions. Thermolysin possessing one mole of zinc(II) ion as a cofactor was covalently immobilized onto porous glass beads. The immobilized enzyme was packed into a small polymer column and mounted in a water-jaketed holder. The biosensing system was assembled with sample injection valves, the column unit and a flow-through quartz cell attached to a UV/VIS detector. Tris-HCl buffer (0.05 M, pH 8.0, 0.1 M NaCl, with or without 2 mM CaCl2) as a carrier solution was continuously pumped through the system. The catalytic activity was assessed by injecting 1.0 ml of 2.5 mM N-(3-[2-furyl] acryloyl)-gly-leu amide as a substrate. The column was regenerated by introducing 100 mM EDTA solution (pH 4.0) to remove zinc(II) ions complexed in the active site of the enzyme molecules. Zinc(II) ions in submicromolar levels were photometrically determined through its reactivation of apoenzyme, i.e., metal-free enzyme. Performance characteristics of the system were examined.

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22.

ƒAƒ|y‘fŠˆ«‰»–@‚É‚æ‚éƒtƒFƒ€ƒgƒ‚[ƒ‰[ƒŒƒxƒ‹‚̈Ÿ‰”(II)ƒCƒIƒ“‚ÌŒv‘ª \ƒAƒ‹ƒJƒŠƒtƒHƒXƒtƒ@ƒ^[ƒ[ƒJƒ‰ƒ€‚Ì“K—p\

²“¡¶’jE‹TŽR‰ë”VE”Ñ“c‘×L

_“ÞìH‰È‘åŠwE‰ž—p‰»Šw‰È

DETERMINATION OF ZINC(II) IONS AT FEMTOMOLAR LEVEL BY USING AN APOENZYME REACTIVATION METHOD \APPLICATION OF AN ALKALINE PHOSPHATASE COLUMN\

Ikuo SATOH, Masayuki KAMEYAMA, and Yasuhiro IIDA

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

A spectrophotometric flow-injection analysis(FIA) with an alkaline phosphatase column was applied to ultratrace analtsis of zinc(II) ions based on the apoenzyme reactivation methods(ARM). Alkaline phosphatase, a kind of typical metalloenzymes, was covalently immobilized onto porous glass beads with controlled pore size and then, packed into a small polymer column. The FIA system was assembled with the enzyme column and a flow-injection photometric device. Tris-HCl buffer (0.1 M, pH 8.0, 1.0 M NaCl, 0.1 uM citrate) as the carrier solution was continuously pumped through the system. Sample solutions were introduced into the system via rotary injection valves. The catalytic activity of the enzyme-packed column was assessed by injecting 0.1 ml of 2.0 mM p-nitrophenyl phosphate(pH 8.0) as a substrate. Zinc(II) ions in subfemtomolar levels were determined by using the ARM. Performance characteristics of the sensing system armed with the enzyme column as a specific recognition element for zinc(II) ions were investigated.

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23.

ƒAƒ“ƒh[ƒv…‘fI’[ƒ_ƒCƒ„ƒ‚ƒ“ƒh‚ð—p‚¢‚½ISFET‚Ì“Á«•]‰¿

r–Ø—T‘¾Aä@rŽA”~‘ò@mA—§–Ø@ŽÀA쌴“c—m

‘‘å—HECREST‰È‹Z’c

CHARACTERISTICS OF UNDOPED HYDROGEN DIAMOND ISFET

Yuta ARAKI, Toshikatsu SAKAI, Hitoshi UMEZAWA, Minoru TACHIKI, and Hiroshi KAWARADA

Department of Electronics, Information and Communication Engineering, School of Science and Engineering, Waseda University
Ohkubo 3- 4- 1 Shinjuku- ku, Tokyo 169- 8555, Japan

For electrochemical applications, diamond has many advantages such as wide potential window, chemical inertness and biocompatibility. Undoped hydrogen terminated diamond exhibits p-type surface conduction and also has wide potential window. An ISFET (Ion Sensitive Field Effect Transistor) is fabricated on that diamond for the first time. The gate area of ISFETs is exposed to electrolyte solution directly without insulator or any sensing layers. It is observed that this type of ISFET is operated clearly either acid or alkaline solutions. From the characteristics in this experiment, it is obtained that the threshold voltage of diamond ISFET depends on the density of Cl- ions in spite of pH value. This property of diamond ISFET is advantageous to Cl- ions sensor.

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24.

—L‹@‹à‘®”––ŒŒnƒCƒIƒ“ƒZƒ“ƒVƒ“ƒOƒfƒoƒCƒX‚Ì“d‹C‰»Šw‡¬

‚£‘ŽqC´…—zˆê

‹ãH‘åH

ELECTROCHEMICAL PROCESSING OF METAL-COMPLEX THIN-FILMS FOR ION SENSING DEVICE

Satoko TAKASE and Youichi SHIMIZU

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

Metal-complex thin-films of Co-, Ni-, Cu-, Zu-, Sn- phthalocyanine-based sys tems could be prepared by an electrochemical deposition method onto indium t in oxide (ITO)-glass substrates from organic solutions for ion sensing devic e. Metal-complex thin-films with high quality and stability could be deposi ted anodically under fixed DC field between 5 and 100V at RT. Among the Co-b ased complexes prepared, the cobalt phthalocyanine thin-film electrode showe d good potentiometric sensing to H2O2. EMF was linear to the logarism of H2 O2 concentration between 1.0x10-6~1.0x10-3M with 90% response time of ca.1mi n at 20BC. While, the cobalt naphthalocyanine thin-film electrode showed the best amperometric sensing to H2O2, i.e., an anodic current at +0.75V vs. SCE was linear to H2O2 concentration between 1.0x10-6~1.0x10-3M with 90% respons e time of ca.30s.

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25.

•¡‡Œõ“±”g˜H•Î”gŠ±ÂŒv‚ð—p‚¢‚½ŒÅ‰tŠE–Ê”½‰ž‚̃‚ƒjƒ^ƒŠƒ“ƒO

ŒV@Žu”üCˆÉ“¡Œö‹IC‘º—Ñ^sC¼“c’¼Ž÷


‰¡•l‘—§‘åŠwC•¨Ž¿HŠwH‹Æ‹ZpŒ¤‹†Š

Monitoring of interaction on the solid-liquid interface by use of composite optical waveguide polarimetric interferometers

Zhi-mei Qi, Kiminori Itoh, Masayuki Murabayashi and Naoki Matsuda*

Institute of Environmental Science and Technology, Yokohama National University
Yokohama 240-8501, Japan
*National Institute of Materials and Chemical Research
Tsukuba 305-0041, Japan

The composite optical waveguide (COWG) has been reported as a highly sensitive polarimetric interferometer for chemical/biological sensing applications [1, 2]. By use of reactive materials such as ZnO, WO3 and ITO as the tapered films of COWG's, the polarimetric interferometers can also serve as disposable sensors to monitor various solid-liquid reactions and to detect the reactive species in the liquids. Etching of the sputtered WO3 film with basic water and etching of the sputtered ZnO film with HCl acid have been monitored and the results indicates that changes of 1 A in thickness can be determined easily in the case of several mm etching length. This paper describes detection of HF by use of bare single-mode PIE waveguides as polarimetric interferometers.

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26.

‘Ï”My‘f‚ð—p‚¢‚½•\–ÊŒõ“dˆ³–@‚É‚æ‚é“œ—ÞƒoƒCƒIƒZƒ“ƒT‚ÌWω»“¯ŽžŒv‘ª

–؈êmA“à“cG˜aAŸ•”º–¾AΊۗY‘åA”Ñ“c•—g

é‹Ê‘åH

INTEGRATION AND SIMULTANEOUS DETECTION OF THE SACCHARIDE BIOSENSORS BY MEANS OF LIGHT ADDRESSABLE POTENTIOMETRIC SENSOR USING THERMOSTABLE ENZYMES

Kazuhito AOKI*, Hideaki UCHIDA**, Teruaki KATSUBE**,Yoshihiro ISHIMARU*, and Takeaki IIDA*

*Department of Functional Materials Science
**Department of Information and Computer Sciences ,Faculty of Engineering, Saitama University
255 Shimo-okubo, Urawa-shi, Saitama-ken 338-8570, Japan

Saccharides sensors, using thermostable enzymes and Light Addressable Potentiometric Sensor (LAPS) system, were developed. The reproducible response, standard deviation of 0.81, was obtained by more than 20 times measuring at 1 mM glucose concentration at room temperature. We integrated the sensors so that the simultaneous detection of saccharides was simplified and the present sensors revealed good correlation. Moreover, we constructed the sensor using beta-glucosedase. At high temperature up to 60Ž, the sensor response for D-salicin was less than that in room temperature. However, the detection was possible. So, the present LAPS sensor is expected to sense other beta-glucosidic glycosides or lactose, because lactose is hydrolyzed by beta-glucosedase at high temperature.

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27.

•\–ʃvƒ‰ƒYƒ‚ƒ“‹¤–‰»ŠwƒZƒ“ƒT‚ð—p‚¢‚½|‚Ìø‘¢H’öŠÇ—

¬‘ºŒõOA•lŒû—CŽ÷AMŽRŒ’ŽŸA‘–ì‰p“ñA‹àŒ´@âêA“ìŒËGmA‘ååM‘½‰ÂŽu

‹à‘òH‹Æ‘åŠwA‚“xÞ—¿Œ¤‹†‰ÈŠwŠJ”­ƒZƒ“ƒ^[

FERMENTATION PROCESS CONTROL OF THE VINEGAR USING SURFACE PLASMON RESONANCE CHEMICAL SENSOR ENZYMES

Mituhiro KOMURA, Yuuki HAMAGUCHI, Kenji NOBUYAMA, Eiji KUSANO, Akira KINBARA, Hidehito NANTO, Takashi OYABU

Adv. Mat. Sci. R&D Center, Kanazawa Inst. of Tech.
3-1 Yatukaho Mattou-shi, Ishikawa 924-0838, Japan
*Kanazawa University of Economics

A chemical sensor based on surface plasmon resonance (SPR) with four channels in studied for quality control of the fermentation process of vinegar. Each channel of the SPR sensor with distilled water as a reference liquid responds to a change in quality of the fermentating vinegar. The SPR sensor, in which aqueous acid solution is used as the reference liquid, also responds to different kind of vinegar. These results strongly suggest that the SPR chemical sensor is useful for quality control and for identification of the type of vinegar.

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28.

Au-SiO2-Au‘½‘w–Œ‚ð—p‚¢‚½•\–ʃvƒ‰ƒYƒ‚ƒ“‹¤–ƒZƒ“ƒT

‘ê“c—ºˆê*AŠOŽRŽ A‘埖õˆê*A’ôŽR‹`l

‘—§ƒŠƒnƒrƒŠŒ¤AHŠw‰@‘åH*

SPR SENSOR BASED ON Au-SiO2-Au MULTILAYER

Ryoichi TAKITA*, Shigeru TOYAMA, Yasukazu OHKATSU*, and Yoshihito IKARIYAMA

Research Institute, National Rehabilitation Center for the Disabled
4-1 Namiki, Tokorozawa 359-8555, Japan
*Faculty of Engineering, Kogakuin University
1-24-2 Nishishinjuku, Shinjukuku, Tokyo 160-0023, Japan

An SPR sensing device with multilayer of Au-SiO2-Au was designed and fabricated. This device was designed to have absorption in the reflected light of both p- and s-waves. By the computer calculation, we found that the absorption angle of p-wave changes when the refractive index in the vicinity of outermost Au layer, while that of s-wave changes little. Therefore, we can expect to cancel out the dirft of baseline by subtracting the latter absorption angle from the former one. The device was fabricated on a glass substrate by EB evaporation and RF supattering, and we could monitor the absorption of p- and s-waves simultaneously.

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29.

ƒ}ƒ‹ƒ`y‘fƒ`ƒbƒv‚Ì컂Ɖ»Šw”­ŒõƒCƒ[ƒWƒ“ƒO

•½–ì@—ICŠ‹¼dMC–{’n’¼”üC¼àV¼•FC––‰i’qˆê

“Œ–k‘å‰@H

IMAGING OF LOCALLY IMMOBILIZED ENZYMES BY SCANNING CHEMILUMINESCENCE MICROSCOPY

Yu HIRANO, Shigenobu KASAI, Naomi MOTOCHI, Matsuhiko NISHIZAWA, and Tomokazu MATSUE

Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University
Sendai 980-8579, Japan

A scanning chemiluminescence microscopy (SCLM) has been developed and used for imaging the spots of glucose oxidase (GOD) and Uricase, formed on a solid substrate. SCLM equips a scanning capillary tip (diameter, 2um) for injecting a small amount of luminol over the enzyme spots. The enzyme reaction-induced chemiluminescense at the spots was detected with a photon-counter. Two-dimensional mapping of the photon-counting intensity against the tip position gave images of which contrast reflects the activity of immobilized GOD and Uricase.

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30.

ƒGƒoƒlƒZƒ“ƒg”g—ã‹NŒuŒõ–@‚É‚æ‚éƒGƒXƒgƒƒQƒ“‚âƒIƒŠƒS‚c‚m‚`‚̃Zƒ“ƒVƒ“ƒO

ŽÂŒ´Š°–¾A‹àŠÛ—eŽqAŽ³ŒË¹•F

‰ªŽR‘åH

BIOAFFINITY SENSING FOR ESTROGEN AND THE TARGET OLIGONUCLEOTIDE BY FLUORESCENCE MEASUREMENT USING EVANESCENT WAVE-EXCITATION

Hiroaki SHINOHARA, Youko KANEMARU, and Masahiko SISIDO

Department of Bioscience and Biotechnology, Faculty of Engineering, Okayama University
3-1-1 Tsushima-naka, Okayama 700-8530, Japan

Fluorescence measurement using evanescent wave excitation was applied to perform high sensitive and convenient bioaffinity sensing for biologically important information molecules. At first, the sensing for 17ƒÀ-estradiol (E 2) was performed at the concentration range from 10-11 to 10-7 M by using competitive binding reaction of free E2 and the E2-modified protein adsorbed on the optical waveguide to the Cy5-labeled anti-E2. At second, sensing for the target oligonucleotide which is a flagment of the p53 gene, a tumer suppressor gene, was performed at the concentration range from 10-9 to 10-6 M by using competitive hybridization reaction of the the Cy5-labeled and the non-labeled target oligonucleotides with the complimentary oligonucleotide probe immobilized on the optical waveguide. Convenient detection of the single-base mismatches of the target oligonucleotide was also demonstrated.

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31.

ƒJ[ƒhŒ^ƒqƒXƒ^ƒ~ƒ“ŒŸoƒ}ƒCƒNƒƒVƒXƒeƒ€‚ÌŠJ”­

—Ñ@‘׌\A¡ˆä‹½ŽqA’|ŽRtŽqA¼‰i@¥

“Œ‹ž”_H‘åH

DEVELOPMENT OF A CARD STYLE MICROSYSTEM FOR HISTAMINE DETECTION

Tae-Kyu LIM, Satoko IMAI, Haruko TAKEYAMA, and Tadashi MATSUNAGA

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

A glass fiber membrane coated with ƒÁ-glycidoxypropyltrimethoxysilane was prepared and used as a novel cation exchange column. This system consists of an immunoreaction portion, a cation exchange glass fiber membrane, and the flow cell for electrochemical detection of ferrocene conjugated IgG. The assay yielded a linear relationship between signal and HCG concentration in the range of 0 - 2000 mIU/mL. This simple and convenient technique permits the assay of HCG within 2 min.

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32.

”½‰žŠíEŒŸoŠíWÏŒ^ƒ}ƒCƒNƒƒfƒoƒCƒX‚ð—p‚¢‚½ƒOƒ‹ƒ^ƒ~ƒ“Ž_‚Ì‘I‘ðŒŸo

—Ñ@Ÿ‹`CŒI“c—»“ñ*C–x“à@•×C’O‰H@C

NTT¶ŠˆŠÂ‹«Œ¤‹†ŠCNTTƒAƒhƒoƒ“ƒXƒeƒNƒmƒƒW*

SELECTIVE DETECTION OF L-GLUTAMATE USING A MICRO DEVICE INTEGRATED WITH A DETECTOR AND A PRE-REACTOR

Katsuyoshi HAYASHI, Ryoji KURITA*, Tsutomu HORIUCHI, and Osamu NIWA

NTT Lifestyle and Environmental Technology Labs.
3-1 Morinosato Aoyama, Atsugi, Kanagawa 243-0198, Japan
*NTT Advanced Technology
3-1 Morinosato Aoyama, Atsugi, Kanagawa 243-0124, Japan

We developed a microfabricated sensor integrated with electrodes and a pre-reactor to eliminate electroactive interferents and thus achieve high selectivity for in vivo monitoring of L-glutamate. The sensor consists of two glass plates. One incorporates 3 gold film electrodes that work as detection, reference and counter electrodes. The other plate has a thin layer flow channel integrated with a pre-reactor. We fabricated a large number of micro-pillars 20 um in diameter, 20 um high and separated from each other by a 20-um gap. The surfaces of these micro-pillars were immobilized with ascorbate oxidase to eliminate L-ascorbic acid and they were fabricated in the channel upstream of the detection electrode. As a result, we were able to achieve the selective detection of L-glutamate in the sample solution containing high L-ascorbic acid concentration.

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33.

—U“d‰j“®Œ»Û‚É‚æ‚éHPLC•ª”zÜ”÷—±Žq‚Ì•ßWE”ro‹Zp‚ÌŒ¤‹†

m‰È’C•vA–]ŒŽ@—ºA—§‰Ô˜aGA‰““¡¹•qA‰““¡FŽuAˆäŒ´’‰—Y

ŽRŒ`‘åHŠw•”•¨Ž¿‰»ŠwHŠw‰È

FIXING AND REMOVAL OF HPLC COLUMN PACKAGING PARTICLES BY USING DIELECTROPHORESIS

Tatuo NISHINA, Ryo MOCHIZUKI, Kazuhiro TACHIBANA, Masatoshi ENDO, Takashi ENDO and Tadao IHARA

Department of Chemistry and Chemical Engineering@Faculty of Engineering, Yamagata University
4-3-16, Johnan, Yonezawa, Yamagata, 992-8510, Japan

We are developing new HPLC system. The concept of this new HPLC system based on the use of dielectrophoresis of column packaging particle under the non-uniform electric fields formed on the micro-band array electrode. By using the dielectrophoresis, it is possible to control the attracting force and repulsive force to the electrically neutral particles by controlling the frequency and the amplitude of ac voltage at the micro-band array electrode, and this enables us to control the column packaging particle such as silica-ODS for introducing them into the micro-column, tie up them on the micro-band array electrode in micro-column by applying attracting force mode, remove them from the micro-column by applying repulsive force mode. In this paper, we report the some results to demonstrate how this new concept for HPLC works by applying ac voltage signal to the silica-ODS particles on the micro-band array electrode as functions of frequency, voltage amplitude, solvent system.

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34.

ƒCƒ“ƒeƒŠƒWƒFƒ“ƒgƒ‚ƒXƒL[ƒgi‚h‚hj

“¿“c’q‹vA¬—Ñ–MKA—é–Ø”ŽÍ

’}”g‘啨Ž¿H

INTELLIGENT MOSQUITO (II)

Tomohisa TOKUDA, Kuniyuki KOBAYASHI, and Hiroaki SUZUKI

Institute of Materials Science, University of Tsukuba
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan

In realizing a minaturized analysis system, a sampling mechanism which functions in a reversible manner is indispensable. Such a reversible sampling mechanism was realized utilizing the volume-phase transition of poly(N-isopropylacrylamide) gel. The novel sampling mechanism features a silicone rubber layer which helps to remove water overflowed from a shrunken gel. The gel changed its volume in response to the change in temperature and accompanying reproducible movement of the internal solution in the flow channel was observed. The sampling mechanism was used in a miniaturized analysis system imitating a mosquito on which a micro glucose sensor and a microscopic platinum needle of 50-ƒÊm inner diameter were formed. After the output current of the sensor was stabilized at 30Ž, an external sample solution was introduced into the flow channel on the chip at 37Ž by the sampling mechanism. A distinct current increase was observed following the sampling. A linear calibration curve was obtained for glucose concentrations less than 10 mM.

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35.

ƒvƒƒeƒI[ƒ€‰ðÍ‚Ì‚½‚ß‚ÌR‘̃`ƒbƒv‚ÌŽŽì

¬“ˆŒªˆêA—é–Ø”ŽÍA•½’Ë~“T*A–î–ì˜a‹`*A’r‘܈ê“T*AŒy•”ª•v*

’}”g‘啨Ž¿HA“Œ‘åæ’[Œ¤*

FABRICATION OF AN ANTIBODY CHIP FOR PROTEOME ANALYSIS

Kenichi KOJIMA, Hiroaki SUZUKI, Atsunori HIRATSUKA*, Kazuyosi YANO*, Kazunori IKEBUKURO*, and Isao KARUBE*

Institute of Materials Science, University of Tsukuba
1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573, Japan
RCAST,*The University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan

An antibody chip was microfabricated for proteome analysis. Thirty-six platinum working electrodes were formed on a glass chip by photolithography along with two Ag/AgCl reference electrodes and two auxiliary electrodes. An anti-human IgG was immobilized on one of the working electrodes with a plasma-polymerized film. An IgE (mouse monoclonal) as a sensing element was immobilized on each working electrode and an anti-mouse IgG (glucose oxidase conjugate) was used as a model analyte. After the analyte was bound to the antibody immobilized on the working electrode, a solution containing glucose was added. Distinct current increase was observed upon the addition.

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36.

‰ß|Ž_‚Ɖߎ_‰»…‘f‚Ì“d‹C‰»Šw“¯Žž•ªÍ

‚nM.I. AWAD, C.HARNOODE*, ‰ª“‡•‹`A“¿“ckˆêA‘åâ•’j

“ŒH‘呇—HE—H‹¦ŽY*

SIMULTANEOUS ELECTROANALYSIS OF PEROXYACETIC ACID AND HYDROGEN PEROXIDE

Mohamed Ismail AWAD, Chokto HARNOODE*, Takeyoshi OKAJIMA, Koichi TOKUDA and Takeo OHSAKA

Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
*Research & Technology Development Department, Ricoh Kyosan, Inc.
7-22 Midori-cho, Kawaguchi, Saitama 332-0027, Japan

The electrochemical behavior of peroxyacetic acid (PAA) in the presence of hydrogen peroxide (H2O2) has been investigated using cyclic voltammetry and hydrodynamic techniques(rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry). Gold electrode was successfully used for this purpose. Based on the RDE experiments, good calibration curves were obtained for both species over a wide range of their concentrations: for PAA and H2O2 in the range of 0.36 to 110 and 0.11 to 34 mM, respectively. The simultaneous and selective electroanalysis of PAA and H2O2 in their coexistence is demonstrated for the first time.

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37.

‘å‰ßè‚̉ߎ_‰»…‘f‹¤‘¶‰º‚É‚¨‚¯‚é‰ß|Ž_‚Ì“d‹C‰»Šw•ªÍ

‚nM.I. AWAD, C. HARNOODE*, ‘åâ•’j

“ŒH‘呇—HE—H‹¦ŽY*

ELECTROANALYSIS OF PERACETIC ACID IN THE PRESENCE OF A LARGE EXCESS OF HYDROGEN PEROXIDE

Mohamed Ismail AWAD, Chokto HARNOODE* and Takeo OHSAKA

Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
*Research & Technology Development Department, Ricoh Kyosan, Inc.
7-22 Midori-cho, Kawaguchi, Saitama 332-0027, Japan

Square wave voltammetry (SWV), with its known sensitivity and rapidity, has been used for simultaneous electroanalysis of peracetic acid (PAA) and hydrogen peroxide (H2O2) in the presence of a large excess of H2O2, up to hundred times the concentrations of PAA. Gold electrode with careful pretreatment was used for this purpose. Using SWV, good calibration curves for the reduction of both species were obtained with correlation coefficients higher than 0.996. The detection limit for PAA was found to be 45 mM.

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38.

ƒvƒ‰ƒYƒ}d‡–Œ‚ð”í•¢‚µ‚½”’‹àü‚ÌpH‰ž“š“Á«

–—´•FCŒ´“c“Þ”ü]C“àŽRrˆê

é‹ÊH‘åH

pH RESPONSE OF PLATINUM WIRE ELECTRODE MODIFIED BY PLASMA POLYMERIZED THIN FILM

Tatsuhiko YAJIMA, Namie HARADA, Shunichi UCHIYAMA

Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Institute of Technology
Okabe, Saitama 369-0293, Japan

The platinum shows the Nernstian response based on the formation of the oxide layer at the surface that depends on pH change in a sample solution. However, the Nernstian response is easily interfered by contaminants in the sample such as chloride ions, vitamins or urine in a biological sample solution. This is because why the control of such interference is an important research subject. In this study, a plasma chemically modified platinum wire electrode was prepared with a low-temperature p-xylene plasma, and the characteristics of the pH response was investigated: in particular the dependence on plasma conditions such as radio-frequency power (P), flow rate of p-xylene (rp-XY) and plasma treatment time (tTR). Consequently, it was cleared that an optimum plasma condition exists to obtain the pH response excellent in the linearity. The average slope of pH response against Prp-XY-1tTR-1 plot may provide some hints to estimate such an optimum condition to get the excellent linear relationship between pH and the potential response.

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39.

ƒzƒ‚ƒGƒsƒ^ƒLƒVƒƒƒ‹ƒ_ƒCƒ„ƒ‚ƒ“ƒh“d‹É‚Ì“d‹C‰»Šw•ªÍ‚ւ̉ž—p

‹ß“¡„ŽjA‰h’·‘×–¾ABulusu V. SaradaATata N. RaoADonald A. TrykA“¡“ˆ@ º

“Œ‘å‰@H

BORON-DOPED HOMOEPITAXIAL DIAMOND ELECTRODES FOR ELECTROANALYSIS

Takeshi KONDO, Yasuaki EINAGA, Bulusu V. SARADA, Tata N. RAO, Donald A. TRYK, and Akira FUJISHIMA

Department of Applied Chemistry,Graduate School of Engineering, Uniersity of Tokyo,
7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan

In order to study the properties of single-crystal boron-doped diamond electrodes for electroanalysis, (100) and (111) boron-doped homoepitaxial single-crystal and polycrystalline diamond thin films were deposited by means of microwave plasma-assisted chemical vapor deposition (MPCVD). Features in the cyclic voltammograms (CVs) for aqueous H2SO4 supporting electrolyte and [Fe(CN)6]3-/4- in aqueous Na2SO4 for polycrystalline electrodes were dominated by behavior typical of (111) single-crystal facets, rather than (100) facets. The (111) homoepitaxial film performed better than a polycrystalline film in the cyclic voltammetric detection of serotonin, with signal-to-background (S/B) ratios of 9 and 3, respectively. Single-crystal diamond electrode may thus be an even better electrode material for electroanalysis than polycrystalline diamond, which have been reported so far as one of the best electrode materials.

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40.

“±“d«ƒ_ƒCƒ„ƒ‚ƒ“ƒh“d‹É‚ð—p‚¢‚½ƒAƒfƒmƒVƒ“ŒnŠjŽ_¬•ª‚Ì“d‹C‰»ŠwŒŸo

B. V. Sarada, Tata N. Rao, D. A. Tryk, “¡“ˆ@º

“Œ‘å‰@H

LIQUID CHROMATOGRAPHIC DETECTION OF ADENOSINE AND RELATED COMPOUNDS USING HIGHLY BORON-DOPED DIAMOND ELECTRODES

Bulusu V. SARADA, Tata N. RAO, Donald A. TRYK and Akira FUJISHIMA

Department of Applied Chemistry, Graduate School of Engineering The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan

A HPLC method for the detection of adenosine, its nucleobase adenine and related nucleotides such as adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP) with amperometry using highly boron-doped diamond thin-film as the electrochemical detector is described in this work. Adeosine oxidizes at ~1.3 V vs. SCE. A linear dynamic range of 4 orders was obtained with a detection limit of 500 nM. Highly reproducible results were obtained. No deactivation of the electrode surface was found showing that there is no adsorption of oxidation products on the electrode surface.

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41.

“±“d«ƒ_ƒCƒ„ƒ‚ƒ“ƒh“d‹É‚É‚æ‚éƒNƒƒƒtƒFƒm[ƒ‹‚Ì“d‹C‰»ŠwŒŸo

Ž›“‡ç»ATata N. RaoAB. V. SaradaA“¡“ˆ@º

“Œ‘å‰@H

ELECTROCHEMICAL DETECTION OF CHLOROPHENOLS AT BORON-DOPED DIAMOND ELECTRODES

Chiaki TERASHIMA, Tata N. RAO, B. V. SARADA, and Akira FUJISHIMA

Department of Advanced Interdisciplinary Studies, School of Engineering, University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan

Anodically oxidized diamond electrode was used for the measurement of chlorophenols (ClPs) with good stabilities. The anodization of as-grown boron-doped polycrystalline diamond thin-film electrodes has made the stable determination of phenols possible, due to lack of adsorption of oxidation products on the surface. After prolonged use, a moderately fouled electrode could be regenerated by the applied high anodic potential.

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42.

“¯ˆê•¨Ž¿‚ðŠîŽ¿‚Æ‚·‚é•¡”y‘f–Œ‚ð—L‚·‚éŽ_‘fŒŸoŒ^‚m‚`‚c+ƒZƒ“ƒT

“àŽRrˆêA’·“‡Šì‘ã•FA’·’J•”–õ

é‹ÊH‘åH

AN OXYGEN DETECTION BASED NAD+ SENSOR WITH BIENZYME MEMBRANE CATALYZING THE SAME SUBSTRATE

Shunichi UCHIYAMA, Kiyohiko NAGASHIMA and Yasushi HASEBE

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

The enzymatic oxidation of glucose to gluconolactone can be carried out by not only glucose oxidase (GOD) but also glucose dehydrogenase (GDH) using nicotinamide adenine dinucleotide (NAD+) as coenzyme.@In these reactions, glucose oxidase@reaction consumes oxygen but glucose dehydrogenase reaction consumes not oxygen but NAD+. Then, when NAD+. is added to the GDE solution in which GOD reaction of glucose had taken place, the consumption rate of oxygen in GOD reaction should be decreased by commencing GDE reaction, because glucose works as a common substrate of both enzymatic reactions. In this work, a coimmobilized polyacrylamide membrane of GOD and GDH was combined with an oxygen electrode. This sensor response was increased in proportional to the added NAD+ (linear concentration range is from 5 x 10-5 M to 2 x 10-3 M with a detection limit of 2 x 10-5 M). The use of oxygen electrode with gas permeable membrane should increase the selectivity of the present NAD+ sensor because non-volatile electroactive species in the sample solution are not detected. The detection of NAD+ based on the same principle has been carried out by using alcohol oxidase and alcohol dehydrogenase and ethanol as the common substrate, and it has been found that to increase of dehydrogenase activity is very important to get higher sensitivities in the present method.

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43.

ƒtƒFƒmƒ`ƒAƒWƒ“Œn“dŽqƒƒfƒBƒG[ƒ^[ŒÅ’艻ƒJ[ƒ{ƒ“ƒtƒFƒ‹ƒg‚ð “d‹C‰»ŠwŒŸoŠí‚Æ‚·‚é‚m‚`‚c‚g‚̃tƒ[•ªÍ

”’ˆä@‹MsA’·“‡@’qGA’·’J•”@–õA“àŽR@rˆê

é‹ÊH‘åEH

FLOW INJECTION ANALYSIS OF NADH USING ELECTROCHEMICAL DETECTOR CONPOSED OF FENITHIAZINE-ELECTRON MEDIATOR-IMMBILIZED CARBON FELT

Takayuki SHIRAI, Tomohiro NAGASHIMA, Yasushi HASEBE, and Shunichi UCHIYAMA

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

Water soluble electron-transfer mediator, thionine (TN) was covalently immobilized onto the surface of cyanuric chloride-activated porus carbon felt (CF) through amino group of TN, and was used as a flow-through detector for on-line assay of NADH. TN-immobilized CF (TN-CF) was mounted into electrochemical cell (30 mm, 10 mm, 10 mm) and connected to the analytical pump. Reproducible peak-shape currents were observed at applied potential +0.2V vs. Ag/AgCl. Under the optimum conditions (carrier flow rate; 2.0 ml/min, pH 8.0, applied potential +0.2 V vs. Ag/AgCl), the peak current responses were proportional to NADH concentration up to 125 uM with a detection limit of 1 uM.

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44.

ƒ|ƒŠƒAƒ~ƒmŽ_-ƒNƒƒŒƒ‰ƒtƒFƒŒƒhƒLƒVƒ“CüŽ_‰»ƒCƒ“ƒWƒEƒ€“d‹É‚É‚æ‚éNADP+‚ÌŠÒŒ³

¼ŽRŸ•FA’r粎õ”üAŽOdˆÀOA’JŒû@Œ÷

ŒF–{‘åH

ELECTROCATALYTIC REDUCTION OF NADP+ ON POLY-AMINOACID-CHRORELLAFERREDOXIN MODIFIED INDIUM OXIDES

Katsuhiko NISHIYAMA, Hisami IKEBE, Yasuhiro MIE, and Isao TANIGUCHI

Department of Applied Chemistry & Biochemistry, Faculty of Engineering, Kumamoto University, Kurokami, Kumamoto 860-8555, Japan

Chrorella ferredoxin(ChFd), which acts as an electron transfer protein in photosynthesis, was immobilized electrostatically with the aid of cationic poly-amino acid such as poly-lysine onto the indium oxide electrode. In the presence of ferredoxin-NADP+(FNR) reductase and NADP+, NADP+ was reduced to NADPH electrocatalitically at the modified electrode. Immobilization both ChFd and FNR on the electrode was also succeeded and worked well for the detection of NADP+.

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45.

‹â/ƒ`ƒI[ƒ‹Œn‚ÌŽ©ŒÈ‘gD‰»’P•ªŽq‘wŒ`¬”½‰ž‚ð—˜—p‚µ‚½ƒAƒZƒ`ƒ‹ƒRƒŠƒ“ƒGƒXƒeƒ‰[ ƒ[Šˆ«‘ª’è

¼‰YGºA²“¡@‰*AàVŒû—²”Ž*A…’J•¶—Y,*

’}”g‘剻EŽY‘Œ¤*

DETERMINATION OF ACETYLCHOLINESTERASE ACTIVITY BASED ON THE FORMATION OF SELF-ASSEMBLED MONOLAYERS ON SILVER ELECTRODES

Hiroaki MATSUURA, Yukari SATO*, Takahiro SAWAGUCHI*,and Fumio MIZUTANI,*

Department of Chemistry, University of Tsukuba
1-1-1 Tennou-dai, Tsukuba, Ibaraki, 305-8571, Japan
*Advanced Industrial Science and Technology
1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan

In order to determine the acetylcholinesterase(AChE) activity with high sensitivity, we have developed a unique, stripping voltammetric method. Frist, thiocholine, which was produced through the AChE-catalyzed hydrolysis of acetylthiocholine, was adsorbed on a silver electrode surface. Next, the reductive desorption of the thiocholine was carried out. From the charge passed during the desorption process, the amount of adsorbed thiocholine could be determined. The charge was proportional to the AChE activity from 0.08 to 0.4U/l. Hence the present method could be used for the determination of the enzyme activity.

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“Á•Êu‰‰.

–¡ŠoƒZƒ“ƒT

“sb@Œ‰

‹ã‘åƒVƒXƒeƒ€î•ñ‰ÈŠwŒ¤‹†‰@

TASTE SENSOR

Kiyoshi TOKO

Department of Electronics, Graduate School of Information Science and Electrical Engineering, Kyushu University
Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan

A multichannel taste sensor, i.e., electronic tongue, is composed of several kinds of lipid/polymer membranes for transforming information of substances producing taste into electric signals, which are input to a computer. The sensor output shows different patterns for chemical substances which have different taste qualities such as saltiness, sourness and bitterness, while it shows similar patterns for chemical substances with similar tastes. The sensor responds to the taste itself, as can be understood from the fact that taste interactions such as the suppression effect, which appears between sweet and bitter substances, can be reproduced well. The suppression of the bitterness of quinine and a drug substance by sucrose can be quantified. Amino acids can be classified into several groups according to their own tastes based on sensor outputs. The taste of foodstuffs such as beer, mineral water and sake can be discussed quantitatively using the taste sensor, which provides the objective scale for the human sensory expression. The taste sensor will open doors to a new era of food and environmental sciences.

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46.

–Ñ”¯ƒ_ƒ[ƒW“x‚̊ȈՕ]‰¿–@‚ÌŒŸ“¢

ŽR“à@—ÍA‹“‡‚Ђë‚Ý*AX“cŽ‘—²**A‘ºã—T“ñ**A‰¡ŽRŒ›“ñ**A–¯’J‰hˆê**

ƒAƒŠƒ~ƒmAƒr[ƒ[ƒh*A–k—¤æ’[‘å**

IEXAMINATION@OF@A@SIMPLIFIED@METHOD@FOR@ASSESSING@HAIR@DAMAGE

C.YamauchiCH.Ushijima*CY.Morita**CY.Murakami**CK.Yokoyama**CE.Tamiya**

Arimino Co.,Ltd.,Sayama Lab.
1-12-1 Shinsayama,Sayama-shi,Saitama,350-1331,Japan
*Broad Co.,Ltd.
**School of Materials Science,Japan Advanced of Science and Technology

As hair-dyeing fashion becomes more popular in recent years, there is an increasing tendency for hair damages. A simple method for assessing hair damage is becoming important. In addition, as the life cycle for hair cosmetics becomes shorter, there is a stronger need in product development for a quick method to evaluate damaged hair. In the past, hair damage is generally assessed by making an over-all evaluation of changes in form and in chemical, physical properties. However, the traditional method requires complex instrument and operating procedure. A simple and practical method was developed by determining the amount of ionic chemical absorption in hair to assess hair damage. This new method was compared against the traditional method.

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47.

ƒ‹ƒeƒjƒEƒ€ö‘Ì‚Ì“d‰ð”­Œõ‚ð—˜—p‚µ‚½ŒŸoŠí‚É‚æ‚éƒyƒvƒ`ƒh‚Ì•ªÍ

]“ª’¼‹`A–p@‹Ñ‡AZL‹§ŒªAˆê“ñŽOŒb”üA‰F“c‘׎O

L“‡Œ§—§‘åŠw

ANALYSIS OF PEPTIDES WITH THE DETECTORS ON THE BASIS OF ELECTROCHEMILUMINESCENCE OF A RUTHENIUM COMPLEX

Naoyoshi EGASHIRA, Jinshun PIAO, Masanori SUMIHIRO, Emi HIFUMI, and Taizo UDA

Department of Bioresouce Development, School of Bioresouces, Hiroshima Prefectural University
Shoubara-shi, Hiroshima 727-0023, Japan


Two types of electrolytic cells based on electrochemiluminescence of tris(2,2'-bipyridine)ruthenium(II) complex were prepared to determine peptides. One was a miniaturized cell, in a small volume of 0.5 cm3,which can detect peptides having a proline residue at the amino terminal. A calibration curve for Pro-Gly gave a straight line in the concentration range 2 x 10-5 - 5 x 10-4 M. The other was a flow-through detector having a working Pt electrode coated with a ruthenium complex/Nafion film. The detector also responded more strongly to peptides having a proline residue at the amino terminal, Pro-Phe-Arg-MCA and Pro-Leu-Gly-NH2.

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48.

pHƒXƒ^ƒbƒgŒ^”A‘fƒZƒ“ƒVƒ“ƒOƒVƒXƒeƒ€‚É‚¨‚¯‚éŠÉÕ”\ˆË‘¶‹y‚Ñ–WŠQ•¨Ž¿‚̉e‹¿

•ÄŽRŒ’ŽiCŽR“c—S‹KŽqC¬Šâˆê˜YCˆ§â“Nœ\C²“¡¶’j*

‘‘å—HC‘‘åÞŒ¤C_“ÞìH‰È‘åH*

INFLUENCE OF BUFFER CAPACITY AND INTERFERENCE SUBSTANCE ON THE pH-STAT FLOW AMPEOMETRIC SENSING SYSTEM

Kenji YONEYAMA, Yukiko YAMADA, Ichiro KOIWA, Tetsuya OSAKA, and Ikuo SATOH*

Department of Applied Chemistry, School of Science and Engineering; Kagami Memorial Laboratory for Materials Science and Technology, Waseda University
Shinjuku-ku, Tokyo 169-0051, Japan
*Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute of Technology
Atsugi-shi, Kanagawa-ken 243-0292, Japan

The influence of buffer capacities and the interference substance on the performance were investigated using the amperometric urea sensing system in combination with the proposed pH-stat method and flow injection analysis(FIA). The influence of interference substance (L-ascorbic acid; AA) on urea response was tested using two different concentration of phosphate buffer solution (PBS); 10 mM and 20 mM PBS. In the case of 20mM PBS, the influence of AA was more restrained than that in the case of 10mM PBS. Then it was demonstrated that the dependence of urea response on buffer concentration was solved by using the same concentration and composition of buffer in both sample and electrolysis pathes.

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49.

Tri-enzyme^ƒ|ƒŠƒWƒƒ`ƒ‹ƒVƒƒLƒTƒ“Ï‘w–Œ‚ð—p‚¢‚½ ƒAƒ“ƒyƒƒƒgƒŠƒbƒN”A‘fƒZƒ“ƒT

…’J•¶—YA²“¡@‰A–êA”Ñ“‡½ˆê˜Y

ŽY‘Œ¤•ªŽq×–EHŠw

AMPEROMETRIC URE-SENSING ELECTRODE BASED ON A TRI-ENZYME/POLYDIMETHYLSILOXANE-BILAYER MEMBRANE

Fumio MIZUTANI, Yukari SATO, Soichi YABUKI, Seiichiro IIJIMA

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

An amperometric urea-sensing electrode was prepared by immobilizing a tri-enzyme system of pyruvate oxidase (PyOx), pyruvate kinase (PK) and urea amidolyase (UA) on a polydimethylsiloxane (PDMS)-coated electrode. UA catalyzes the ATP-dependent hydrolysis of urea to generate ADP; PK, the phospho-transferring reaction between ADP and phosphoenolpyruvate (PEP) to generate pyruvic acid; PyOx, the oxidation of pyruvic acid with oxygen. The oxygen consumption could be monitored by using a PDMS-coated electrode without interference from the PyOx-reaction product, hydrogen peroxide. Thus the concentration of urea (5 uM - 0.35 mM) could be determined from the decrease in the cathodic current at -0.4 V vs. Ag/AgCl in a test solution containing ATP and PEP. The cathodic detection with the tri-enzyme system provided the urea determination which was free from the error caused by coexisting species such as, acetaminophen, uric acid, phosphate, in the sample to be measured.

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50.

ƒCƒ“ƒrƒ{‘ª’è—pƒOƒ‹ƒR[ƒXƒZƒ“ƒT‚ÌŽŽì‚¨‚æ‚Ñ‚»‚̃Zƒ“ƒT“Á«

ˆÀàVŠ²lCŽR“c“N–çC‚‰ªGŽ÷Cž­@@ÍC¡ˆäMŽ¡*

“¿“‡‘åHC“Œ—m¸–§H‹Æ*

PREPARATION OF NEEDLE TYPE GLUCOSE SENSORS USING ELECTROPOLYMERIZATION PROCEDURE

Mikito YASUZAWA, Tetsuya YAMADA, Hiroki TAKAOKA, Akira KUNUGI and Shinji IMAI*

Department of Chemical Science and Technology, Faculty of Engineering The University of Tokushima
2-1 Minamijosanjima, Tokushima 770-8506, Japan
*Toyo Precision Parts MFG. Co., Ltd.
97-1 Higashinaka, Yamatotakada, Nara 635-0066, Japan

Needle type glucose sensors with a diameter of approximately 0.4 mm were prepared by the electropolymerization of pyrrole derivative, 1-(6-D-gluconamidohexyl)pyrrole (GHP), in the presence of glucose oxidase (GOD). In vitro measurement was performed in the phosphate buffer solution (pH 7.4) and bovine serum at 40 ËšC. Although the introduction of polyurethane outer film lowered the response sensitivity, it was indispensable to obtain sensor response in bovine serum. Moreover, the outer film contributed to improve the response stability of the sensor. The platinum-black plating modification increased the sensor response. In vivo measurement was performed using rats, while no clear response current corresponding to the glucose level was obtained.

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51.

‚g‚q‚o/ƒƒfƒBƒG[ƒ^[ŒÅ’艻‚Q–{½‚c‚m‚`-ƒ|ƒŠƒJƒ`ƒIƒ“•¡‡–Œ“d‹É‚ð—p‚¢‚é‰ßŽ_‰» …‘fƒZƒ“ƒT

Åã@”ŽlA—鎭@˜a³A’·’J•”@–õA“àŽR@rˆê

é‹ÊH‘åEH

HYDROGEN PEROXIDE SENSOR USING HRP AND ELECTRON TRANSFER MEDIATOR-ENTRAPPING DOUBLE STRANDED DNA - POLYCATION COMPLEX MEMBRANE - COATED ELECTRODE

Hirotaka MOGAMI, Kazumasa SUZUKA, Yasushi HASEBE and Shunichi UCHIYAMA

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

Polyion complex (PIC) membrane consisting of double stranded DNA (ds DNA) is useful for the sensing layer of second generation reagentless enzyme sensor. The electron-transfer mediator, methylen blue (MtB), which is intercalated with ds DNA in the PIC film, efficiently mediates electrons from the Au electrode to the redox active center of the HRP. The resulting HRP/DNA MtB/PAA coated electrode exhibited amperometric responses to H2O2 with the relatively fast response time of ~10 s in the concentration range from 3 ~10-6 to 3~10-4 M (M=mol dm-3) with a detection limit of 1~10-6 M H2O2 in 0.1 M phosphate buffer (pH 6.0).

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52.

“±“d«ƒ_ƒCƒ„ƒ‚ƒ“ƒh“d‹É‚ð—p‚¢‚½ƒJƒ‹ƒoƒ[ƒgŽE’ŽÜ‚Ì“d‹C‰»ŠwŒŸo

Tata N. RAO, Boon H. LOO, Donald. A. TRYK, “¡“ˆ@º

“Œ‘å‰@H

ELECTROCHEMICAL DETECTION OF CARBAMATE PESTICIDES AT CONDUCTIVE DIAMOND ELECTRODES

Tata N. RAO, Boon H. LOO, Donald. A. TRYK and Akira FUJISHIMA

Department of Applied Chemistry, School of Engineering The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, JAPAN

Boron-doped diamond electrodes were examined for the electrochemical detection of N-methylcarbamate pesticides, which oxidize electrochemically at high-applied potentials. Diamond due to wide potential window, was able to detect these pesticides after liquid chromatographic separation at an operating potential of 1.45 V vs Ag/AgCl. To reduce the oxidation potential, these pesticides were hydrolysed to phenolic products and were detected at 0.9 V vs Ag/AgCl. In both the detection methods, diamond exhibited higher stability and higher sensitivity in comparison to glassy carbon electrode.

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53.

“±“d«ƒ_ƒCƒ„ƒ‚ƒ“ƒh“d‹É‚ð—p‚¢‚½ŽOŠÂŽ®R‚¤‚ÂÜ‚Ì ‚‘¬‰t‘̃Nƒƒ}ƒgƒOƒ‰ƒtƒB[‚É‚æ‚é”÷—ÊŒŸo

Ivandini T. A.AB. V. SaradaAŽ›“‡ ç»AT. N. RaoAD. A. TrykA“¡“ˆ@º

“Œ‘å‰@H

ELECTROCHEMICAL DETECTION OF TRICYCLIC ANTIDEPRESSANTS BY HPLC USING HIGHLY BORON-DOPED DIAMOND ELECTRODE

IVANDINI T. A., B.V. SARADA, C. TERASHIMA, T. N. RAO, D.A TRYK and A. FUJISHIMA

Department of Advanced Interdisciplinary Studies, Graduate School of Engineering, The University of Tokyo
4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan

Tricyclic antideppressant drugs (TCA's) have been detected at highly boron-doped diamond electrodes using cyclic voltammetry, hydrodynamic voltammetry, flow injection analysis (FIA) and high performance liquid chromatography (HPLC) with amperometric detection. Comparison experiments were carried out using glassy carbon (GC) electrodes. Diamond electrodes were demonstration to be useful for detection of TCA's after HPLC separation. At diamond electrodes, results were obtained with a lower detection limit (LOD) of 0.5 nM (S/N=3) and long-term stability.

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54.

‘Ï”M«ƒvƒƒeƒA[ƒ[FƒT[ƒ‚ƒŠƒVƒ“‚ð—p‚¢‚½ƒ^ƒ“ƒpƒNŽ¿‘ª’è—pƒoƒCƒIƒZƒ“ƒTII

“Iê F·AÎŠÛ —Y‘åA”Ñ“c •—g

é‹Ê‘åH

CHARACTERISTICS OF A PROTEIN SENSOR FOR MONITORING VARIOUS PROTEINS USING THERMOPHILIC PROTEASEGTHERMOLYSIN

Takamori MATOBA, Yoshihiro ISHIMARU, and Takeaki IIDA

Department of Functional Materials Science, Faculty of Engineering, Saitama University
Shimo-okubo, Urawa-shi, Saitama-ken 338-8570, Japan

An ion sensitive field effect transistor (ISFET) protein sensor was studied using a thermophilic proteaseGthermolysin. The sensor was able to monitor various proteins e.g. lysozyme, tripsin inhibiter, et al. at each concentration was 0.01wt% (1mg/10ml) at 45Ž and pH7.3. It was found that hydrogen ions were released when the thermolysin hydrolyzes the peptide bonds. In this reportCit was revealed that the responses of the thermolysin based protein sensor were depended on the molecular weight of various proteins .

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55.

_Œoì—p•¨Ž¿•]‰¿‚Ì‚½‚ß‚Ì×–EƒoƒCƒIƒZƒ“ƒVƒ“ƒOƒVƒXƒeƒ€‚Ì\’z

‹TˆäŒªˆê˜YAtŽR“N–çA–ö“c•ÛŽqA¬”©‰p—A‘ŠàV‰v’j

“ŒH‘嶖½—H

CONSTRUCTION OF THE CELLULAR BIOSENSING SYSTEM FOR ASSESSMENT OF DRUGS FOR THE NERVOUS SYSTEM

Ken-ichiro KAMEI, Tetsuya HARUYAMA, Yasuko YANAGIDA, Eiry KOBATAKE and Masuo AIZAWA

Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology
Yokohama, Kanagawa 226-8501, Japan

The cellular biosensing system for assessment of drugs for the nervous system has developed. In order to assess drugs for CNS, N1E-115 cells, which were neuroblastma cells and neuronal nitric oxide synthase expressed after differentiation, were used in the cellular biosensing system. N1E-115 cells are implemented in the cellular biosensing system, because they respond to the drugs in releasing NO, which is directly monitored with a gold electrode covered with a polyion complex layer. KCl and L-NMMA have been evaluated as model drugs with the cellular biosensing system.

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