Vol. 22, Supplement A (2006)

Proceedings of the 41st Chemical Sensor Symposium
April 1-3, 2006

Abstracts


1.

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

› ‚yhigang ZHUa, Chutia ARUNABHIRAMa, TSUBOIa, Michihisa KOYAMAa,
Akira ENDOUa, Momoji KUBOa, Carlos A. DEL CARPIOa, Akira MIYAMOTOa,b

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

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


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2.

SnO2ƒNƒ‰ƒXƒ^[•ªŽU…—n‰t‚ð—p‚¢‚½‚Š´“x”––ŒŒ^ƒKƒXƒZƒ“ƒT‚ÌŒŸ“¢

‹ã‘å‰@‘—H

‹g“cG•½A›“’ó‰ë‰êA“‡ƒm]Œ›„AŽR“Yúf

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

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

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

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


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3.

’´‰¹”g•¬–¶”M•ª‰ð–@‚É‚æ‚鑽EŽ¿Ž_‰»ƒXƒY
•²––‚Ì’²»‚Æ”¼“±‘̃KƒXƒZƒ“ƒT‚ւ̉ž—p

’·‘åH

•B“ckŽmC›•º“ªŒ’¶C´…N”ŽC]“ª@½

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

Koji HIEDA, Takeo HYODO, Yasuhiro SHIMIZU and Makoto EGASHIRA

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

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


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4.

Ž_‰»ƒXƒY”––Œƒ}ƒCƒNƒƒZƒ“ƒT‚Ì—°‰»…‘fƒKƒXŒŸ’m“Á«‚É‹y‚Ú‚·ƒ}ƒCƒNƒƒMƒƒƒbƒv‚ÌŒø‰Ê

—§–½ŠÙ‘嗝H

›’†“c’J¹“¿AV”ü@A¬¼@‘A‹Ê’u@ƒ

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

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

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

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


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5.

ƒJ[ƒ{ƒ“ƒiƒmƒ`ƒ…[ƒuƒZƒ“ƒT‚̃KƒXŒŸ’m“Á«

iVƒRƒXƒ‚ƒX“d‹@aA‘åã‘åŠwbj@

›ˆÉ“¡’B–çaA–{‘½MˆêbA•ÐŽRŒõ_bA”ö‰YŒ›Ž¡˜Yb

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

Tatsuya Itoa, Shin-ich Hondb, Mitsuhiro Katayamab, *Kenjiro Ourab

aNew Cosmos Electric Co., Ltd., 3-6-25 Mitsuya-naka, Yodogawa-ku, Osaka
bDepartment of Electronic Engineering, Graduate School of Engineering,
Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0872 Japan

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

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6.

‹z’…”RÄ‚ð—˜—p‚µ‚½‚Š´“xTVOCƒZƒ“ƒT‚ÌŠJ”­

–îè‘‹ÆC*’·è‘åH

›ùŒ´—²•FC‰Á“¡”ŽÆCâV“¡ˆŸ–îŽqC¼‘º¹WC]“ª@½*

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

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

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

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

 

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7.

•¡”ƒKƒXƒZƒ“ƒT‚É‚æ‚é‰ÎÐŒ¹Ží‚ƈʒu‚Ì“¯’è

‹à‘ò¯—Å‘å1A‹à‘òH‹Æ‘åŠw2A‹ãB‘åŠw3

V•Û’B–ç1,›ÎžÒ‘å‰î2,“Œ–ì@—ƒ1C‘ò“c@ŽjŽq1C‘å–÷‘½‰ÂŽu1C“ìŒËGm2C“sb@Œ‰3

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

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

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

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

 

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“Á•Êu‰‰

•ÛˆÀ•ª–ì‚É‚¨‚¯‚鉻ŠwƒKƒXƒZƒ“ƒT‚Ì–ðŠ„

VƒRƒXƒ‚ƒX“d‹@Š”Ž®‰ïŽÐ

d·“OŽu

Roles of chemical gas sensors in the filed of safety

Tesshi SHIGEMORI

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

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

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8.

ƒAƒ~ƒhŠî‚ð—L‚·‚鍂•ªŽqŒŸ’m–Œ‚ð“h•z‚µ‚½…»U“®Žq‚É‚æ‚éHClƒKƒXŒŸ’m

ˆ¤•Q‘å‰@—H

›¼Œû³MA–å˜e—ǐl

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

Masanobu MATSUGUCHI, Yoshito KADOWAKI

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

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

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9.

ƒRƒA-ƒVƒFƒ‹Œ^‹àƒiƒm—±ŽqCü‹ùŒ^“d‹É‚Ì—L‹@ƒKƒX‚ɑ΂·‚éƒCƒ“ƒs[ƒ_ƒ“ƒX‰ž“š

ŒF–{‘åH

@›•y‰i ¹lA@“í“c@G–¾A@ŽR–¼—ˆ[ŒbA@’JŒû@Œ÷

IMPEDANCE RESPONSE FOR ORGANIC VAPOR ON INTERDIGITATED
MICROELECTRODE MODIFIED WITH CORE-SHELL AU NANOPARTICLES

Masato Tominaga, Hideaki Kusuda, Kumie Yamana and Isao Taniguchi

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

Gold nanoparticles film can be prepared by crosslinking nanoparticle cores with organic molecules such as bifunctional alkanedithiols. These linker molecules act as insulating barriers between the metal cores, and determine the distances between the metal cores. In this study, we prepared interdigitated microelectrode (IME) covered with Au nanoparticles film by exchange-crosslink process using 11-mercaptoundecanoic acid (MUA), 3-mercaptobenzoic acid (MBA), 1,9-nonanedithiol (NT) and 1,4-benzendimethanethiol (BMT) as linker molecules. Impedance response for Au nanoparticles film modified IME was investigated, when the modified IME was exposed to ethanol, 2-propanol, hexane and toluene vapors. Impedance response strongly depended on volatile organic compounds,
which could be understood by an interaction between organic compound and Au nanoparticles film.

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10.

”¼“±‘ÌŽ_‰»•¨‚ð—p‚¢‚½ƒeƒgƒ‰ƒNƒƒƒGƒ`ƒŒƒ“ƒZƒ“ƒT‚ÌŠJ”­

—§–½ŠÙ‘嗝HAƒtƒBƒKƒ‹ZŒ¤*Aƒ†ƒjƒ`ƒJŠÂ‹«‹ZpƒZƒ“ƒ^[**

›’J•½—´–çA‰ÍŒû’q”Ž*A‰F‚—˜_*A–Ø‘ºŒ\•**AœA“cˆê—Y**A‹Ê’u@ƒ

DEVELOPMENT OF TETRACHLOROETHYLENE SENSOR USING SEMICONDUCTOR OXIDE

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

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

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

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11.


SmFe1-xCoxO3‚ð—p‚¢‚½”¼“±‘ÌŒ^ƒZƒ“ƒT‚Ì’á”Z“xƒIƒ]ƒ“‚ɑ΂·‚鉞“š

ˆ¤•Q‘åH

›X@‰ë”üA@×’J@—SŽ÷A@”Š_@‹gWA@Â–ì@G’ʁA@’艪@–F•F

SENSING PERFORMANCES OF SmFe1-xCoxO3 SEMICONDUCTIVE GAS SENSOR
TO LOW OZONE CONCENTRATION

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

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

We are researching the gas sensors application of perovskite-type oxides prepared by thermal decomposition of heteronuclear complexes. A high sensitivity was obtained for SmFeO3(x=0) even for sub-ppm level of ozone gas. However, the sensor had to be operated at high temperature because its conductivity was relatively low. In this study, the conductivity was controlled by substituting a part of Fe with Co, and sensing performances of SmFe1-xCoxO3 p-type semiconductive gas sensors to low ozone concentrations were examined. The sensitivity of those sensors were measurable at low temperatures due to an increase of their conductivity. The specimen with x=0.1-1.0 showed a high sensitivity at 100Ž or less to low ozone concentrations. Furthermore, the influence of the contamination of several VOCs in monitoring environment was examined. The sensitivity to VOCs showed high value at high temperature. In other hand, at low temperature, the sensitivity to ozone was hardly influenced by VOCs-existence. The partial Co substitution was effective for the detection of ozone containing VOCs.

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12.

Hfƒh[ƒvƒZƒŠƒA‚ð—p‚¢‚½’ïRŒ^Ž_‘fƒZƒ“ƒT‚Ì“Á«

ŽY‘Œ¤

›ˆÉ“¤“TÆAˆÉ“¡•q—YA\ƒEƒ\ƒNA¼Œ´ˆê˜YA‘ºŽRéŒõ*

SENSING PROPERTIES OF RESISTIVE OXYGEN SENSOR
BASED ON Hf-DOPED CERIA

Noriya IZU, Toshio ITOH, 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
* National Institute of Advanced Industrial Science and Technology (AIST)
1-1-1 Umezono, Tsukuba, Ibaraki 305-8568

In this study, in order to investigate hafnia concentration dependence of sensing properties of resistive oxygen sensors using ceria-hafnia system, we fabricated the sensors using ceria thick film doped with various hafnia concentrations. Hf concentration in which the effect of decrease of the resistance was large and in which the resistance measurement was easy was in the range from 3 to 30 mol%. Hf concentration of 7 mol% or more was preferable for the thick films from a perspective of activation energy. Hf concentration of 2 mol% or more was preferable for the thick films from a perspective of sensitivity (oxygen partial pressure dependence of the resistance).

 

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13.

YSZ•\–ʂւ̃Šƒ`ƒEƒ€ƒCƒIƒ““`“±‘w‚ÌŒ`¬‚ÆCO2ƒKƒXƒZƒ“ƒT‚ւ̉ž—p

ˆ¤•Q‘åH

ü­‹g Œ’ŽuA”Š_ ‹gWAÂ–ì G’ʁA’艪 –F•F

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

Takeshi MASAYOSHI, Yoshiteru ITAGAKI, Hiromichi AONO and Yoshihiko SADAOKA

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

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

 

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14.

•¡‡ˆŸÉŽ_‰–•â•‘Š‚É‚æ‚éNASICONƒx[ƒX’ቷì“®Œ^NO2ƒZƒ“ƒT‚̐…ö‹C–WŠQ‚̉ü‘P

–k‹ãB‚ê

¬”¨Œ«ŽŸ, ¼“ˆ–ÎŒ›

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

Kenji OBATA and Shigenori MATSUSHIMA

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

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

 

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15.

¬¬“dˆÊŒ^ƒWƒ‹ƒRƒjƒAƒZƒ“ƒT‚É‚¨‚¯‚é
NO2Š´“x‚ÌŽ_‰»•¨ŒŸ’m‹É–ŒŒú‚ւ̈ˑ¶«

‹ãB‘åŠw1AƒŠƒPƒ“(Š”)2

üƒyƒ‹ƒ}ƒ‹@ƒGƒ‹ƒ}ƒŒƒC1Cƒuƒ‰ƒfƒBƒ~ƒ‹ ƒvƒ‰ƒVƒjƒcƒ@1, ã“c ‘¾˜Y1C’·’Jˆä@­Ž¡2C
ŽO‰Y@‘¥—Y3

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

üPerumal ELUMALAI1, Vladimir V. PLACHNITSA1, Taro UEDA1, Masaharu HASEI2, Norio MIURA1

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


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

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16.

WO3‚ð“Y‰Á‚µ‚½NiOŒŸ’m‹É‚ð—p‚¢‚½¬¬“dˆÊŒ^ƒWƒ‹ƒRƒjƒAƒZƒ“ƒT‚ÌNO2‰ž“š“Á«

(‹ã‘åŽYŠw˜AŒgƒZƒ“ƒ^[aAƒŠƒPƒ“(Š”)b )

›‰¤ Œ’a, Ž›“c ‘叫a, ƒGƒ‹ƒ}ƒŒƒC ƒyƒ‹ƒ}ƒ‹a, ã“c ‘¾˜Ya, ’·’Jˆä ­Ž¡b, ŽO‰Y ‘¥—Ya

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

Jian WANGa, Daisuke TERADAa, Perumal ELUMALAIa, Tarou UEDAa, Masaharu HASEIb, Norio MIURAa

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

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

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17.

ƒAƒ‹ƒ~ƒjƒEƒ€ƒCƒIƒ““`“±‘Ì‚ð—p‚¢‚½V‹K‚ÈNOxƒZƒ“ƒT

ã‘å‰@H

›“c‘º ^Ž¡C’·’Jì Œ÷C¡’† Ml

NITROGEN OXIDES GAS SENSOR BASED ON
ALUMINUM ION CONDUCTING SOLID ELECTROLYTE

Shinji TAMURA, Isao HASEGAWA, Nobuhito IMANAKA

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

A new type of nitrogen oxides gas sensor was fabricated by using aluminum cation conducting solid electrolyte with sensing auxiliary electrode and Al metal thin film loaded on each surface of the electrolyte disk. The present nitrogen oxides gas sensor showed such good sensing performances of rapid, stable, continuous, and reproducible response and a linear relationship between the sensor output and the logarithm of the NO concentration was obtained in the gas concentration range from 200 to 2000 ppm at 250‹C. The sensor output variation with the NO gas concentration change was in an excellent agreement with the theoretical one for the sensor with the KNO3 doped Gd2O3-Nd2O3 solid solution ((Gd0.4Nd0.6)2O3-KNO3) as the sensing auxiliary electrode.

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18.

¬Œ^…‘fƒ|ƒ“ƒvEƒQ[ƒW‚̍쐻‚Æ‚»‚Ì“Á«

iH“c‘åŠwHŠwŽ‘Œ¹Šw•”j

›‹àŽ™hªA ì”¨“N˜YA ‘½“c‰pŽi

PREPARATION AND PROPERTIES OF A MINIATURE HYDROGEN PUMP-GAUGE

Hiroyuki KANEKO, Tetsuro KAWABATA and Eiji TADA

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

A miniature CaZr0.9ln0.1O3-ƒ¿ hydrogen pump-gauge with aperture was constructed and applied to measure hydrogen pressure. Hydrogen pressure was analyzed by Hetric etal.'s method 1) to avoid hydrogen leakage from internal chamber.
It was successfully measured within a few seconds at 600Ž in the range 10-3- 0.07 atm. This device is useful for measuring a steady-state hydrogen pressure and also it can be applied to survey a fluctuated hydrogen pressure.

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19.

Ž_‰»•¨ƒŒƒZƒvƒ^‚ð—p‚¢‚½ŒÅ‘Ì“d‰ðŽ¿ƒCƒ“ƒs[ƒ_ƒ“ƒXŒŸoŒ^NOxƒZƒ“ƒT

‹ãH‘åH

›–Ø’ë‘å•ãAr–Ø—F—¢A‚£‘ŽqA´…—zˆê

SOLID ELECTROLYTE IMPEDANCEMETRIC NOxSENSOR USING OXIDE RECEPTOR

Daisuke KOBA, Yuri ARAKI, Satoko TAKASE and Youichi SHIMIZU

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

The new type solid-electrolyte impedance metric NOx sensor electrochemical device composed of Li1.5Al0.5Ti1.5(PO4)3 (LATP) as the transducer and various oxide (n-type (TiO2, SnO2, WO3), p- type (NiO, Cr2O3) semiconductor and perovskite-type oxide LaBO3 (B= Co, Cr, Ni, Mn, Fe) ) as receptor, respectively, have been systematically investigated for the detection of NOx (NO and NO2) in the range 10-200ppm at 400-500Ž. Responses of these sensors were able to divide component between resistance and capacitance, and it was found that the device is applicable to the selective detection of NO and NO2 concentration in each ingredient. Respectively TiO2, SnO2 (n-type semiconductor) and perovskite-type oxide based receptor gave good response to NO and NO2. We found different response between n-type and p-type semiconductor, tried to elucidate of sensing mechanism.

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20.

ƒAƒpƒ^ƒCƒgŒ^\‘¢‚ð—L‚·‚éLixLn10-xSi6O27-x (Ln=La,Nd,Sm)ŒnŒÅ‘Ì“d‰ðŽ¿‚Ì
ƒCƒIƒ““`“±‚ÆCO2ƒKƒXƒZƒ“ƒT‚ւ̉ž—p

ˆ¤•Q‘åH

›‹{œA@ A“¡“ˆ@ŠwA”Š_‹gWAÂ–ìG’ʁA’艪–F•F

CONDUCTIVITY OF APATITE -TYPE LixLn10-xSi6O27-x(Ln=La,Nd,Sm) AND ITS
APPLICATION FOR POTENTIOMETRIC CO2 GAS SENSOR

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

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

Apatite-type LixLn10-xSi6O27-x (Ln=La,Nd,Sm) (x=0,1,2,3) electrolytes were prepared for the application of potentiometric CO2 gas sensor. The x=2,and 3 samples were single phase and high density by sintered at 1300Ž. Although the conductivity of x=2,and 3 was lower than that of x=0,1, then carrier ion estimated to be Li+ ion. The mixture of Li2CO3 and LixLn10-xSi6O27-x was very stable at below 700Ž. The EMF for the CO2 gas sensor using Li2Nd8Si6O25 drifted in initial stage, and then the EMF showed stable value .

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21.

ˆÀ’艻ƒWƒ‹ƒRƒjƒA‚ÆŽ_‰»•¨ŒŸ’m‹É‚ð—p‚¢‚½“d—¬ŒŸoŒ^ƒZƒ“ƒT‚Ì’Y‰»…‘fŒŸ’m“Á«

‹ã‘å‰@‘—HaA ‹ã‘åŽYŠw˜AŒgƒZƒ“ƒ^[b

›ã“c‘¾˜YaA ’†“¡[LaA ŽO‰Y‘¥—Yb

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

Taro UEDA a, Mitsunobu NAKATOU a, Norio MIURA b

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

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

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22.

“d‹ÉG”}‚ÌŽ_‰»Šˆ«·‚ð—˜—p‚·‚é“d—¬ŒŸoŒ^ŒÅ‘Ì“d‰ðŽ¿
’Y‰»…‘fƒZƒ“ƒT

‹ãB‘åŠw‘åŠw‰@HŠwŒ¤‹†‰@

›ÎŒ´’BŒÈCAtanu Dutta, Zhonghe Bi, ¼–{Ld

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

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

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

Amperometric hydrocarbon sensor using Fe doped LaGaO3 based oxide was investigated and it was found that the selective detection can be achieved by using difference in oxidation activity of electrode. In this study, detection characteristics of Pt-Co-LDC/LSGF(7373)/La0.5Sr0.5MnO3 was studied and furthermore, long term stability was also studied. In order to identify the electrode reaction, impedance analysis was also performed and it was found that the cathodic overpotential is much larger than that of anode. The developed sensor is highly selective to C3H6 and hardly dependent on O2 concentration and also stable sensitivity was kept over 7 days.

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23.

V‹KŒÅ‘ÌŽQÆ‹É‚ð—p‚¢‚½ƒvƒŒƒi[Œ^Ž_‘fƒZƒ“ƒT‚̉ž“š“Á«

‹ã‘å‰@‘—HaA‹ã‘åŽYŠw˜AŒgƒZƒ“ƒ^[b

’†‹v•Û ¹•½aAŽ›“c ‘叫bA›˜aŠÔ —Ç‘¾˜YaAŽO‰Y ‘¥—Yb

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

Shohei NAKAKUBOa, Daisuke TERADAb, ›Ryotaro WAMAa , Norio MIURAb

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

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

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24.

Š®‘S–„ž‚Ý‚ð–ÚŽw‚µ‚½‘gŠ·‚¦y•ê‚ð—p‚¢‚½y‘fƒZƒ“ƒT

•xŽR‘åŠw@HŠw•”1C‘—§Š´õÇŒ¤‹†Š2C‡Šƒfƒ“ƒ\[@Šî‘bŒ¤‹†Š3

ŽRŒû@¹Ž÷1C›’†–ì@“֍s1C’JŽR@’‰‹`2C–öˆä@Œªˆê3

A YEAST TRANSFORMANT-BASED ENZYME SENSOR FOR IMPLANTABLE APPLICATION

Masaki YAMAGUCHI1, Atsunori NAKANO1, Tadayoshi TANIYAMA2 and Kenichi YANAI3

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

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

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25.

“€Œ‹Š£‘‡ŠîŽ¿‚ð—p‚¢‚½”÷¬y‘fŠˆ«‘ª’èƒVƒXƒeƒ€

’}”g‘å‰@”—•¨Ž¿aAƒ„ƒ}ƒTÝ–ûb

›X–{ Ž–çaAƒTƒ“ƒWƒFƒCEƒAƒpƒWƒƒ[aA‘åã ’¼laA“ú‰º•” ‹ÏbA—é–Ø ”ŽÍa

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


Katsuya MORIMOTO a, Sanjay UPADHYAY a, Naoto OHGAMI a, Hitoshi KUSAKABEb, and Hiroaki SUZUKI a

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

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

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26.

•¡”—n‰t‚Ì’€ŽŸ“±“üE”ro‹@\‚Æ‚»‚̃oƒCƒIƒZƒ“ƒVƒ“ƒO‚ւ̉ž—p

’}”g‘å‰@”—•¨Ž¿

—œŽq“c“TOA›²“¡qA—é–Ø”ŽÍ

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

Norihiro NASHIDA, Wataru SATOH, Hiroaki SUZUKI

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

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

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27.

ƒiƒmƒMƒƒƒbƒv“d‹É‚Ì‘n»‚ƃoƒCƒIƒZƒ“ƒT‚ւ̉ž—p

ã•{‘å@æ’[ƒZ

’Ŗ؍OC›°”gŽu•ÛCŠâ–{¹C’·‰ª•×

FABRICATION OF NANO-GAP ELECTRODE AND ITS APPLICATION FOR BIOSENSING

Hiroshi Shiigi, Shiho Tokonami, Masashi Iwamoto, Tsutomu Nagaoka

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

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

 

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28.

‚n‚g‚oƒV[ƒg‚ð—˜—p‚µ‚½ƒiƒgƒŠƒEƒ€ƒCƒIƒ“ƒZƒ“ƒT‚̍쐬‚Æ•]‰¿

i‘—§ƒŠƒnƒrƒŠŒ¤ j

›ŠOŽRŽ 

FABRICATION AND CHARACTERIZATION OF DODIUM ION SENSOR
BASED ON TRANSPARENCY FILM

Shigeru TOYAMA

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

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

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29.

ƒXƒNƒŠ[ƒ“ˆóü‚É‚æ‚é‚R“d‹Éˆê‘ÌŒ^ƒ`ƒbƒv‚̍쐬‚ƁA
ƒyƒvƒ`ƒh‚¨‚æ‚уAƒ~ƒmŽ_‚Ì’¼Ú“I“d‹C‰»Šw‘ª’è

a–k—¤æ’[‘åAbÎìŽY‹Æ‘noŽx‰‡‹@\A ci—LjƒoƒCƒIƒfƒoƒCƒXƒeƒNƒmƒƒW[

›‹ß]@‚Ý‚ä‚«aAˆäŽèã@Œö‘¾˜YbAKagan KermanaA‹“‡@‚Ђë‚ÝcA‚‘º@‘TaA–¯’J@‰hˆêa

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

Miyuki CHIKAEa, Koutarou IDEGAMIb, Kagan KERMANa, Hiromi USHIJIMAc, Yuzuru TAKAMURAa, Eiichi TAMIYAa

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

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

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30.

ŽO“d‹ÉŒn‚Ì•Ï‘¥“IŽg—p‚É‚æ‚éƒIƒ“ƒ`ƒbƒvpHƒXƒ^ƒbƒg‚Æ‚»‚̉ž—p

’}”g‘å‰@”—•¨Ž¿

›X–{ Ž–çA—é–Ø ”ŽÍ

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


Katsuya MORIMOTO and Hiroaki SUZUKI

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

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


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“Á•Êu‰‰

MEMS‹Zp‚ð—˜—p‚µ‚½ƒoƒCƒIƒ`ƒbƒv‚ÌŠJ”­

‘‘嗝H

›ˆ§â@“Nœ\

DEVELOPMENT OF BIOCHIP USING MEMS TECHNOLOGY

Tetsuya OSAKA

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

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

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31.

Ž_‰»•¨ŒnƒGƒŒƒNƒgƒƒNƒƒ~ƒbƒN”––Œ‘fŽq‚æ‚éŠÂ‹«ƒCƒIƒ“ƒZƒ“ƒT

‹ãH‘åH

›’|ˆÀ’qGA‚£‘ŽqA´…—zˆê

AN ENVIRONMENTAL ION SENSOR USING
ELECTROCHROMIC MULICOMPONENT THIN-FILM OXIDE

Tomohiro TAKEYASU, Satoko TAKASE, Youichi SHIMIZU

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

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

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32.

ƒ}ƒCƒNƒ—¬Œo˜H“à‚Ì‚k‚`‚o‚r‚É‚æ‚鑪’è

i“Œ–k‘åHj

› ‹gM ’B•vAˆÉ“¡ ‘IA‹n•£ ’B•vA¼â “ÄŽuA‰Á”[ Tˆê˜Y

LAPS MEASUREMENT OF MICROCHANNELS

Tatsuo YOSHINOBU, Suguru ITO, Tatsuo Kinefuchi,
Atsushi MATSUIZAWA and Shinfichiro KANOH

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

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

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33.

ƒ‹ƒ~ƒm[ƒ‹“d‹C‰»Šw”­Œõ‚Æ“d‹É•\–ʏó‘Ô‚ÌŠÖŒW

ŽÅ‰YH‹Æ‘åŠw‰ž—p‰»Šw‰È

›‹gŒ©–õ’jCŠ™“c³sCŽRãp —DCŠÖª^ˆê

EFFECT OF SURFACE CONDITION ON ELECTROCHEMILUMINESCENCE OF LUMINOL

Yasuo YOSHIMI, Masayuki KAMADA, Yu YAMAGATA, Shinichi SEKINE

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

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

 

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34.

SPR–ƉuƒZƒ“ƒT‚É‚æ‚锚”­«‰»‡•¨‚̍‚‘¬‚Š´“xŒŸo

‹ãB‘åŠwaAJSPSb

›D. ƒ‰ƒr ƒVƒƒƒ“ƒJƒ‰ƒ“a,b, ¼–{ ´c, “sb Œ‰d, ŽO‰Y‘¥—Ya

RAPID AND HIGHLY SENSITIVE SPR IMMUNOSENSOR FOR EXPLOSIVE COMPOUNDS

›Dhesingh RAVI SHANKARANa,b, Kiyoshi MATSUMOTOc, Kiyoshi TOKOd, Norio MIURAa

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

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

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35.

‚QŽŸŒ³‚r‚o‚q–ƉuƒZƒ“ƒT‚̍‚Š´“x‰»

•xŽR‘åHCNTT-AT

›—é–ؐ³NC‰HªV‘¾˜YC‘哇–LOC“ü•”NŒhC”ò“c’B–ç

DEVELOPMENT OF A HIGHLY SENSITIVE TWO-DIMENSIONAL SPR IMMUNOSENSOR

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

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

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

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36.

ƒCƒ“ƒrƒ{‘ª’è—pƒtƒŒƒLƒVƒuƒ‹ƒOƒ‹ƒR[ƒXƒZƒ“ƒT‚ÌŠJ”­

“¿“‡‘åH,@“Œ—m¸–§H‹Æ*,@ƒJƒ“ƒUƒX‘åŠw**

›‚‰ªGŽ÷,@ˆÀàVŠ²l,@´…—˜‘×*,@¡ˆäMŽ¡*,@Raeann Gifford*,@George S. Wilson**

DEVELOPMENT OF FLEXIBLE GLUCOSE SENSORS FOR IN VIVO MEASUREMENT

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

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

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

 

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37.

ƒCƒ“ƒrƒ{‘ª’è—pƒ}ƒ‹ƒ`ƒ`ƒƒƒ“ƒlƒ‹ƒZƒ“ƒT‚ÌŠJ”­

“¿“‡‘åH,@“Œ—m¸–§H‹Æ*,@ƒJƒ“ƒUƒX‘åŠw**

›ˆÀàVŠ²l,@ŒÃìW–ç,@‚‰ªGŽ÷,@Raeann Gifford*,@George S. Wilson**

DEVELOPMENT OF A MULTICHANNEL BIOSENSOR FOR IN VIVO MEASUREMENT


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

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

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

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38.

”A•ªÍ—pƒ}ƒCƒNƒƒvƒŒ[ƒiŒ^ƒAƒ“ƒyƒƒƒgƒŠƒbƒN’_`Ž_ƒoƒCƒIƒZƒ“ƒT[‚ÌŠJ”­

ŽY‘Œ¤ƒoƒCƒIƒjƒNƒXŒ¤‹†ƒZƒ“ƒ^[ aAŠ”Ž®‰ïŽÐƒ^ƒjƒ^ bA
“Œ‹žH‰È‘åƒoƒCƒIƒjƒNƒXŠw•” c

›¬o@“NaAˆÉ“¡@¬ŽjbAçj•”@ª•va, c

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

SATOSHI KOIDE a, NARUSHI ITO b and ISAO KARUBE a, c

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

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

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39.


”A’†8-hydroxy-2'-deoxyguanosine‚Ì“d‹C‰»Šw‘ª’è–@‚ÌŠJ”­

ŽY‘Œ¤@ƒoƒCƒIƒjƒNƒXŒ¤‹†ƒZƒ“ƒ^[aAiŠ”jƒ^ƒjƒ^bA“Œ‹žH‰È‘åc

›ˆî—t@—m•½aAˆÉ“¡@¬ŽjbA‰¡ŽR@Œ›“ñaAçj•”@ª•va, c

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

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

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

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

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

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

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40.

ƒEƒŒƒA[ƒ[Eƒxƒ“ƒ[ƒ“ƒWƒ`ƒI[ƒ‹EƒqƒhƒƒLƒmƒ“¬‡“d‰ðd‡–Œ‚ð—p‚¢‚½
‰ßŽ_‰»…‘f‚Ì‘I‘ð“I“d‰ðŽ_‰»‚ÉŠÖ‚·‚錤‹†

ié‹ÊH‘å‰@Hj

› ŠÖ‰ª ’¼sA²“¡ ’q—mA“àŽR rˆê

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

Naoyuki.SEKIOKA, Tomohiro.SATO, Shunichi.UCHIYAMA

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

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

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41.

“d‹C‰»Šwy‘f–Ɖu‘ª’è–@‚É‚æ‚éƒiƒgƒŠƒEƒ€—˜”Aƒyƒvƒ`ƒhƒzƒ‹ƒ‚ƒ“ŒŸo

ŽY‘Œ¤

›ŽOdˆÀO*A‘å{‰ê—F”ü‰À*A•½–ì—I*A’O‰HC**A…’J•¶—Y*

HIGHLY SENSITIVE MEASUREMENT OF ATRIAL NATRIURETIC PEPTIDE BY
ELECTROCHEMICAL ENZYME IMMUNOASSAY

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

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

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

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42.


Uric Acid Sensor Using the Uricase Immobilized Membrane
Composed of Polystylene and Polymaleimidostylene

é‹ÊH‘å

›Wang Yung XiuA”‹Œ´Žž’jA“àŽRrˆê


URIC ACID SENSOR USING THE URICASE IMMOBILIZED MEMBRANE COMPOSED OF
POLYSTYLENE
AND POLYMALEIMIDOSTYLENE

›Xiuyun WANGa,b, Tokio HAGIWARAa, Shunichi UCHIYAMAa

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

‚‚Anshun University of Science and Technology,185 Qianshan Zhong Road,
Anshan, Liaoning, China

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

 

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43.

G”}‘fŽq‚ðŒÅ’艻‚µ‚½DNA-ƒ|ƒŠƒAƒ~ƒ“•¡‡–Œ‚ð”FŽ¯‘fŽq‚Æ‚·‚é
ƒAƒ“ƒyƒ ƒƒgƒŠƒbƒNƒoƒCƒIƒZƒ“ƒT

é‹ÊH‘åH

›’·’J•”@–õATingting Gu

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

Yasushi HASEBE, Tingting GU

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

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

 

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44.

ƒtƒFƒƒZƒ“ƒ{ƒƒ“Ž_‚ð—p‚¢‚½ƒŠƒ|ƒ|ƒŠƒTƒbƒJƒ‰ƒCƒh‚Ì“d‹C‰»Šw“IŒŸo

JST-CRESTAŽY‘Œ¤

›‰Á“¡‘åA”Ñ“‡½ˆê˜YA²“¡‰AJia JianboAŒI“c—»“ñA…’J•¶—YA’O‰HC

ELECTROCHEMICAL DETECTION FOR LIPOPOLYSACCHARIDE USING FERROCENYLBORONIC ACID

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

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

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

 

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45.

ƒXƒNƒŠ[ƒ“ˆóü“d‹É‚ð—p‚¢‚½ŠÈˆÕŽc—¯”_–òƒZƒ“ƒT

–k—¤æ’[‘åÞ—¿‰ÈŠwaA•xŽRŒ§”_‹ÆŽŽŒ±êbA–k“l‰ÈŠwŽY‹ÆiŠ”jcAƒoƒCƒIƒfƒoƒCƒXƒeƒNƒmƒƒW[d

‰i’J®‹Ia,‹ß]‚Ý‚ä‚«a,Kagan Kermana,’†“c‹Ïb,‹ß“¡Œ“Žic,‹“‡‚Ђë‚Ýd,‚‘º‘Ta,›–¯’J‰hˆêa

RESIDUAL PESTICIDES DETECTION SENSOR USING SCREEN PRINTED ELECTRODE.

Naoki NAGATANIa, Miyuki ChIKAEa, Kerman KAGANa, Hitoshi NAKADAb,
Kenji KONDOc, Hiromi USHIJIMAd, Yuzuru TAKAMURAa, Eiichi TAMIYAa

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

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

 

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46.

ALP-ŒÅ’艻•¨[“UƒJƒ‰ƒ€‚ð—p‚¢‚½ˆŸ‰”ƒCƒIƒ“‚ÌSIA

_“ސìH‰È‘åH

›²“¡¶’jCŒ´“c’mKCûü‹´‹v”üŽqC”Ñ“c‘׍L

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

Ikuo SATOH, Toshiyuki HARADA, Kumiko TAKAHASHI, Yasuhiro IIDA

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

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

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47.

•ªŽq’’Œ^ƒXƒeƒ[ƒ‹ƒZƒ“ƒT‚ÌŠJ”­‚Æ”ñNPŒv‘ª

ã•{‘å@æ’[ƒZ

›’Ŗ؍OC[àV‘C’·‰ª•×

Development of Molecularly Imprinted Sterol Sensor and Non-invasive Detection

Hiroshi Shiigi, Satoshi Fukazawa, Tsutomu Nagaoka

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

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

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