Gas Sensing Characteristics of Rare Earth Metal Oxide Thin Films
Toshiyuki ASAKURA, Yoshihiro TAKEMITSU, Ryoki NOMURA,
Masashi AZUMA, and Yoshikane KAWASAKl
Department of Applied Chemistry,
Faculty of Engineering, Osaka Institute of Technology,
Ohmiya, Asahi-ku, Osaka 535, Japan
Gas sensing characteristics of rare-earth ( Ln ) oxide thin films have been
investigated. Several rare-earth ( Ln = Y,Nd ) sesquioxides ( LN2O3 ) thin films were deposited on an Al2O3 substrate by RF sputtering technique. The electrical conductivities of these thin films at 5.0V(DC) increased with increasing temperature in N2 atmosphere. The electrical conductivities increased when the films exposed to 10ppm of H2 or CO gas at 300Ž, whereas did not change when exposed to O2 or CO2.
2.
ƒpƒ‹ƒX‹ì“®•ûŽ®SnO2ŒnƒKƒXƒZƒ“ƒT
“¡X—TŽ÷A–ØŒÕ^‹IA¼‰Y‹g“WAŠŽR—T‹v
ƒtƒBƒKƒ‹ZŒ¤
PULSE DRIVE SnO2 GAS SENSOR
Yuki FUJIMORI, Maki KITORA, Yoshinobu MATSUURA
and Yoshihisa KAJIYAMA
Figaro Engineering, INC.
Minoo-shi, Osaka 562, Japan
A pulse drive gas sensor was developed to lower power consumption. The sensor element has a multilayer structure formed by a screen-stenciled process on an aluminum substrate. The gas sensing layer was pulsatively heated by the RuO2 heater. In the case of a duty ratio of 8/1000 every 1sec, the effective power consumption was about 14mW. The sensing materials of the sensor were also studied. Pt/SnO2 sensor showed high sensitivity, good selectivity and quick response to CO, and was hardly effected by humidity.
3.
Ž¼“x•âžŒ^SnO2ŒnƒKƒXƒZƒ“ƒT
^“瑾—SA–쑺“OA¼‰Y‹g“WAŠŽR—T‹v
ƒtƒBƒKƒ‹ZŒ¤
HUMIDITY COMPENSATED SnO2 GAS SENSOR
Taisuke Manabe,Tohru Nomura,Yoshinobu Matsuura,Yoshihisa Kajiyama
Figaro Engineering Inc.
l-5-3 Senbanishi,Minoo-shi,Osaka 562, Japan
An integrated gas sensor composed of a gas sensing element and a water vapor sensing element was developed by a screen-stenciled process. The same Pd/SnO2 layer was printed on both elements and only the water vapor sensing element had a glass layer printed on its surface. Compared to the gas sensing element, the water vapor sensing element showed almost the same sensitivity and response to water vapor, but showed very little sensitivity to reducing gases such as ethanol, hydrogen and carbon monoxide.Therefore, the water vapor sensitivity of the gas sensing element could be easily eliminated by using the water vapor sensing element.
4.
ƒ`ƒ^ƒ“Ž_‰–‚ð—p‚¢‚½‚‰·Œ^NOxƒZƒ“ƒT
ŽR‰YO”VA‹Ê’uƒAŽO‰Y‘¥—YAŽR“Y úf
‹ã‘呇—H
TITANATE - BASED NOx SENSORS OPERATIVE AT ELEVATED TEMPERATURES
Hiroyuki YAMAURA, Jun TAMAKI, Norio MlURA, and Noboru YAMAZOE
Department of Materials Science and Technology,
Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816, Japan
A series of metal titanates was examined for their NOx sensing properties at elevated temperatures. Among them, BaTiO3 and SrTiO3 were found to be remarkably sensitive to NO and/or NO2 existing in air at 500Ž. BaTiO3 was especially sensitive to NO2 at 500Ž, although its response was rather sluggish at this temperature. On the other hand, SrTiO3 gave lower but still fairly high sensitivity to NO2 together with practically acceptable response rates at 500Ž. Notably, its sensitivities to NO and NO2 were almost equal to each other and increased linearly with increasing NOx concentration in the range of 5-100 ppm. The resistance of the element using SrTiO3 was almost independent of oxygen concentration in the range of 3`15% . The NOx sensing mechanism of this element was briefly discussed.
Shuzo KUDO, Hisao OHNISHI, Satoshi TAKANO*, Mitsunobu WAKATA*, Ryo USAMI*,
Hisao YAMAUCHI*,and Hisasi SAKAI**
Osaka Gas Co., Ltd. , Konohana-ku, Osaka, 554, Japan *Superconductivity Research Laboratory, ISTEC, Koto-ku, Tokyo, 135 Japan **Kansai Research Institute, Shimogyo-ku, Kyoto, 600, Japan
We have developed NO sensors made of Bi2Sr2(Ca1-yYy)Cu2Ox (y=0, 0.8) thin films. Bi2Sr2(Ca1-yYy)Cu2Ox (y=0, 0.8) thin films showed the high sensitivity at low concentrations of NO and also showed hardly any selectivity to H2, CO and CH4 which are present in exhaust gases . These thin films were deposited on the MgO substrate by the laser ablation method. We measured the Hall effect of Bi2Sr2(Ca0.2Y0.8)Cu2Ox thin film to study the NO sensing mechanism. The results of the Hall effect measurements elucidated that the electrical conductivity of the sensor mainly determined by the change in the hole density which was decreased by the adsorption of NO.
6.
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ŒIŒ´‹ÅA“c’†LˆêA™ŽR˜a•v
é‹Ê‘åH
NOx SENSING PROPERTIES OF PEROVSKITE-TYPE OXIDES
Yoshiaki KURIHARA, Shinichi TANAKA and Kazuo SUGIYAMA
Department of Applied Chemistry, Faculty of Engineering,
Saitama University, 255, Shimo-okubo, Urawa 338, Japan
NOx(NO,NO2) sensing properties of various perovskite-type oxides (ABO3:A=La3+, Nd3+, Sm3+; B=Cr3+, Mn3+, Fe3+, CO3+) have been investigated at 450 Ž. The thick film (ca. 20ƒÊm) of the perovskite oxide sintered on the ƒ¿-alumina substrate was used for the sensor element. A NOx sensitivity of the elements was influenced by differences of the B site metal ions. Especially, a superior sensitivity to NOx gas molecules appeared when the B site was made up by Cr3+ and Fe3+ ion respectively. The substitution of Sr2+ to the A site of LaFeO3 element led to an increase of NOx sensitivity.
7.
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‹ã‘呇—H
NOx SENSING PROPERTIES OF METAL CARBONATE-BASED SENSORS AT ELEVATED TEMPERATURES
Koichi FUJIMORI, Jun TAMAKI, Norio MIURA, and Noboru YAMAZOE
Department of Materials Science and Technology,
Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816, Japan
Semiconductor-type gas sensors using alkaline earth metal carbonates were investigated for a detection of NOx in air at elevated temperatures. Among those tested, the sensor using BaCO3 was found to exhibit the highest sensitivity to NO and NO2. With increasing operating temperature in the range of 600-700 Ž, the sensitivity of BaCO3 sensor decreased, while the response and recovery characteristics were improved. This suggests that the optimum temperature of the present sensor is 650 Ž. At this temperature, the sensitivities to both NO and NO2 were equal to each other and increased almost linearly with increasing concentration in the range of 0`400 ppm. The cross sensitivities to other several components of exhaust gas were also examined at 650 Ž.
8.
Šó“y—ÞA“º‚Ì•¡‡Ž_‰»•¨‚ÌNOxŒŸo“Á«
œA“c—m•½A¡’†MlA‘«—§‹á–ç
ã‘åH
NOx SENSING PROPERTIES OF RARE EARTH COPPER OXIDES
Yohei HIROTA, Nobuhito IMANAKA, and Gin-ya ADACHI
Department of Applied Chemistry,
Faculty of Engineering,Osaka University
2-1 Yamadaoka,Suita,Osaka 565, Japan
The NOx (NO, NO2) sensing characteristics of semiconducting Ln2Cu2O5(Ln=Tb,Tm,Yb etc.) compounds were investigated. The electrical resistivity of the Yb2Cu2O5 oxide bulk decreased with the increase of the NO2 concentration at the temperatures below 550Ž. The oxide was insensitive to the NO content change in the temperature region above 500Ž. This clearly indicates that the Yb2Cu2O5 semiconducting material responds only to NO2 among NOx gases at the operating temperatures around 550Ž.
â–ì WA¡’†MlA‘«—§‹á–ç
ã‘åH
THE NOx SENSING PERFORMANCE OF SCANDIUM-DOPED NICKEL COPPER OXIDE THIN FILM
Susumu BANNO, Nobuhito IMANAKA and Gin-ya ADACHI
Department of Applied Chemistry, Faculty of Engineering,
Osaka University
2-1 Yamadaoka, Suita, Osaka 565, Japan
Scandium-doped nickel copper oxide bulk, which consists of Ni0.8Cu0.2O, CuO, Sc2O3, and Sc2Cu2O5, responded only to NO2 (50-500 ppm) among NOx gases. Thin films of the oxide were prepared by a RF magnetron sputtering method, and their NOx sensing performances were investigated. The electrical resistivity of the film decreased with the increase in the NO2 concentration, while it increased with the NO content. As was expected, the film responded to NO2 more sensitively than the bulk shape did. However, the film responded to both NO2 and NO. The disappearance of crystalline Sc2Cu2O5 in the film might affect the sensing behavior for NOx.
10.
La2CuO4‚É‚¨‚¯‚铱“d—¦‚ÌNOx”Z“xˆË‘¶«
’·’JˆäŽ¡*A•Ä‘º—F‹IA…胈ê˜Y**A“c씎Í
ƒŠƒPƒ“*A‰¡•l‘‘åŠÂ‰ÈŒ¤ƒZA“Œ–k‘å‰ÈŒ¤**
DEPENDENCE OF La2CuO4 CONDUCTIVITY ON NOx CONCENTRATION
Masaharu HASEI* , Yuki YONEMURA,
Junichiro MIZUSAKI** and Hiroaki TAGAWA *Riken Co.,4-14-1 Suehiro, Kumagaya-shi, Saitama 360, Japan
Institute of Environmental Science and Technology Yokohama
National Univ.,156 Tokiwadai, Hodogaya-ku, Yokohama 240, Japan **RISM, Tohoku Univ., 2-1-1 Katahira, Aoba-ku, Sendai 980-77, Japan
The conductivity of La2CuO4 was measured in O2-N2, and NOx- O2-N2 atmospheres at temperatures 500-750Ž. The conductivity in O2-N2 atmospheres increased with the oxygen concentration, but was independent of temperature. In NO2-O2-N2 atmospheres, the conductivity increased with the NO2 concentration. The variations in the conductivity with NO2 concentration were greater than those with the same concentration of O2, moreover the conductivity decreased with temperature. In NO-O2-N2 atmospheres, the conductivity did not change with NO concentration and temperature. Because NO2 continuously decomposed on the surface of La2CuO4, the oxygen activity on the surface became extraordinary high, resulting in the large oxygen excess nonstoichiometry and the increase of p-type conductivity.
ŠâŠÙG“TA¬—Ñ ŒõA’†ŒË‹`âX
ã‘åŠî‘bHA—L‹@ŒõƒZƒ“ƒ^[
MECHANISM OF HYDROGEN - INDUCED VOLTAGE SHIFTS OF THE CURRENT-VOLTAGE CURVES FOR PLATINUM / SILICON OXIDE / SILICON MIS TUNNELING DIODES
Hidenori Iwadate, Hikaru Kobayashi, and Yoshihiro Nakato
Research Center for Photoenergetics of Organic Materials,
and Department of Chemistry, Faculty of Engineering Science,
Osaka University, Toyonaka, Osaka 560, Japan
We have attributed the shifts of ‡T-V curves for the MIS tunneling diodes caused by hydrogen to the following three factors: i) the decrease in the effective Pt work- function, ii) the movement of protons in the silicon oxide layer, and iii) the formation of interface states through the reaction between protons and Si / silicon oxide interface. The time constant for the formation of the interface states increases with the hydrogen concentration, which is explained by the formation of two-dimensional aggregations of the interface states.
¼—Yˆê˜YAÎŒ´’BŒÈA‘ê“c—Sì
‘啪‘åH
Adsorption State of CO2 on CuO-BaTiO3 and the Characterization of Energy Barrier at Grain Junction between CuO and BaTiO3.
Yuichirou Nishi, Tatsumi Ishihara, Yusaku Takita,
Department of Applied Chemistry, Faculty of Engineering,
Oita University, Dannoharu 700, Oita 870-11, Japan
Capacitance of CuO-BaTiO3 is highly sensitive to CO2 detection. In this study, detection mechanisms of CuO-BaTiO3 capacitor were investigated. Since the adsorption of CO2 is stronger than that of O2 upon CuO-BaTiO3, adsorption of CO2 make the trapped electron free resulting in the increased electron density in CuO-BaTiO3. It is expected that increased electron density decreased the height of energy barrier and narrowed the width of the depletion layer at the junction of p-type CuO and n-type BaTiO3. From this point, adsorption of CO2 on CuO-BaTiO3 is similar with the application of forward bias potentials to p-n junction. It became clear that capacitance of the element increased upon exprodure to CO2 as a result of decreased width of depletion layer at the junction between CuO and BaTiO3.
13.
”––ŒƒWƒ‹ƒRƒjƒA‹ó”R”äƒZƒ“ƒT
—é–Ø—²”VA–Ø–ìCA‰ÃŽRt•v*A“ñ“c•äÏ
–îèŒvŠíA–îè•”•i*
THIN-FILM ZIRCONIA AIR TO FUEL RATIO SENSOR
Takayuki SUZUKI, Osamu KINO, Haruo KAYAMA* and Hozumi FUTATA
Yazaki Meter Co.,Ltd. Gas Equipment Development Department
23 Minamikashima, Futamata-cho, Tenryu-shi, Shizuoka 431-33, Japan *Yazaki Parts Co.,Ltd.
Conpornent manufacturing engineering Department
206-1 Nunohikihara, Haibara-cho, Haibara-gun, Shizuoka 42l-04, Japan
Thin film limiting current-type oxygen sensor based upon a porous alumina substrate has interresteing characteristics in the case of the voltage applied to the electrolytic cell
changes from usual direct current to alternating current. It appear to be able to measure not only oxygen concentration in oxidation combustion exhaust but also hydrogen concentration in reduction combustion exhaust. The sensor output has a good linearity to oxygen and hydrogen concentration and its polarity is changed by which is the atmosphere around the sensor oxidation or reduction.
14.
“V‘RƒKƒX‹@ŠÖŽOŒ³G”}ƒVƒXƒeƒ€—pŽ_‘fƒZƒ“ƒT‚ÌŒŸ“¢i‚Pj
Žç‰Æ_“ñA²ŒÃFO
‘åãƒKƒX
DEVELOPMENT OF OXYGEN SENSOR FOR 3-WAY CATALYST SYSTEM ON NATURAL GAS ENGINE (1)
Koji MORIYA and Takahiro SAKO
Research and Development Center, Osaka Gas Co.,Ltd.
6-19-9 Torishima, Konohana-ku, Osaka-shi, Osaka 554, Japan
A window tracking sensor, which can detect the window of the deteriorated catalyst, was required for precise A/F control. Owing to the analysis of the catalyst deterioration mechanism, an oxygen sensor with low methane oxidation activity was supposed to show a good performance. Methane oxidation activities and sensor characteristics of 2 sensors on the market and a sample prepared according to the patent was measured. Strong correlation was found between them.
15.
Na2OEAl2O3E4SiO2/ZrO2•¡‡–Œ‚ð—p‚¢‚½CO2ƒZƒ“ƒT
ƒwƒ‹[EƒXƒvƒŠƒAƒgƒmA’艪–F•FAƒAƒ“ƒhƒŒƒAƒXEƒfƒ…ƒx, Žðˆä‹`˜Y
ˆ¤•Q‘åH
CO2 SENSOR USING Na2O ¥ Al2O3 ¥ 4SiO2 / ZrO2 COMPOSITES
Heru SUPRIYATNO, Yoshihiko SADAOKA, Andreas DUBBE and Yoshiro SAKAI
Department of Applied Chemistry Faculty of Engineering
Ehime University, Matsuyama-shi, Ehime 790, Japan
ABSTRACTS
The sensing characteristic of CO2 gas sensor using the combination of Na2O¥Al2O3¥4SiO2 glass and Yttria-stabilized Zirconia was examined. The sensor exhibited a good sensitivity and fast response but a little effect of water vapor still appeared. At temperature higher than 400Ž, the sensor makes a good agreement with Nernst's equation based on 2 electrons.
16.
ˆÀ’艻ƒWƒ‹ƒRƒjƒA‚ð‚×[ƒXމȂƂµ‚½¬Œ^CO2ƒZƒ“ƒT
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CHIP-TYPE CO2 SENSOR BASED ON STABILIZED ZIRCONIA
Seijiro NONAKA, Yongtie YAN, Norio MIURA, and Noboru YAMAZOE
Department of Materials Science and Technology,
Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816, Japan
A planar-type solid electrolyte CO2 sensor was fabricated by using a chip of MgO-stabilized zirconia (MSZ) and an auxiliary phase of a metal carbonate (Li2CO3). The EMF response of the sensor was found to vary logarithmically with CO2 concentration, following the Nernst's equation for the 2-electron reaction of CO2 in the range of 100-2000 ppm at 500-650 Ž. The CO2 sensitivity of this sensor was hardly affected by coexistent O2, H2, NO, NO2, or H2O. The CO2 sensing mechanisms of the MSZ-based sensor was discussed on the basis of the concept of an intermediate layer at the interface of heterojunction.
’r“c͈ê˜YA‹ß“¡’B–çA‰Á“¡’å•vAˆÉ“¡ —vA–쑺Ÿ—T*A“¡“c—Yk**
–¼H‘åA‘åHŒ¤*A“ú–{“d’r**j
DEVELOPMENT OF CO2 GAS SENSOR USING MULTI-CATIONIC CONDUCTING SOLID ELECTROLYTES
Shoichiro IKEDA, Tatsuya KONDO, Sadao KATO, Kaname ITO, Katsuhiro NOMURA*
and Yuko FUJITA**
Department of Applied Chemistry, Nagoya Institute of Technology
Gokiso-cho, Showa-ku, Nagoya 466, Japan * Inorganic Material Dept., Government Industrial Research Institute Osaka
Midorigaoka 1, Ikeda, Osaka 563, Japan ** Development Dept., Corporate R & D Center, Japan Storage battery Co., Ltd.
Nishinosho, Kisshoin, Minami-ku, Kyoto 601, Japan
We have systematically investigated on a series of the multi-valent cationic conducting solid electrolytes having zirconium phosphate frameworks. Among them, MgZr4(PO4)6 (MgZP) shows a relatively high divalent cationic conductivity promising an application for electrochemical devices such as a solid state gas sensors. EMF type CO2 gas sensors, having following cell construction; Pt | CO2, O2 | alkaline carbonate || solid electrolyte | O2, Pt. In the case of Na2CO3, the sensor showed the Nernstian response to CO2 in the pressure range between 1 and 100 kPa at temperatures from 400 to 500 Ž within a few minutes. Using partially Si-substituted MgZP (MgZrPSiO), the Nernstian response temperature range has been expanded to 300 Ž although it takes a longer response time.
18.
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ŽRŽ”ÍsA“¡‰ª “§A“n•ÓË•¶A“yˆäŒª”VA”¦ˆä ’A‘“ã”É—Ê
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PLANER TYPE CO SENSOR USING PLASMA-POLYMERIZED SOLID ELECTROLYTE
Noriyuki Yamaga, Toru Fujioka, Yoshihumi Watabe
Kenji Doi, Takashi Hatai, Shigekazu Kusanagi
Central Research Laboratory, Matsushita Electric Works, Ltd.
1048, Kadoma. Osaka, Japan
A planer type electrochemical CO sensor was developed using a new solid electrolyte prepared by plasma-polymerization of trifluorochloroethylene (TFCE) and trifluoromethanesulfonic acid (TMSA) and the performance of the sensor were investigated. A linear calibration curve was obtained in the range from 25ppm to 500ppm with the 90% response time of about 20sec and the detection limit (S/N=2) was 0.5ppm.
19.
‹â‰»‡•¨‚ÌNO2ŒŸ’m“Á«
•ÐŠ Œ÷Aã—ÑF“NA²“¡GŽ÷A‹´–{Šì—TA“cŒ´ C
“‡’ûìŠ
NO2 SENSING CHARACTERISTICS OF Ag IONIC CONDUCTORS
Shimadzu Corporation,l Nishinokyo-kuwabaracho,
nakagyo-ku ,Kyoto, 604, Japan
NO2 Sensing characteristics of several silver ionic conductors were investigated by potentiometry and Ag2S was found to give good response to NO2 from room temperature to 200Ž . The sensor showed stable EMF and linear relationship to logarithms of NO2 concentration. As low as 8ppb of NO2 colud be detected at 27Ž. CO2,O2,NO,H2O and SO2 have little interference to the NO2 response of the sensor.
20.
‚‰·Œ^ƒvƒƒgƒ““±“d‘Ì‚ð—p‚¢‚½…“¯ˆÊ‘̃Zƒ“ƒT
“ú”ä–ì‚ŽmAŠâŒ´Oˆç
–¼‘åH
AMPEROMETRIC SENSOR FOR MEASUREMENT OF D2O CONCENTRATION IN WATER ISOTOPES USING HIGH TEMPERATURE TYPE PROTONIC CONDUCTOR
Takashi HIBINO and Hiroyasu IWAHARA
Synthetic Crystal Research Laboratory, School of Engineering,
Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-01, Japan
Amperometric sensor for the measurement of D2O concentration in a mixture of H2O and D2O has been studied using CaZr0.9In0.1O3-ƒ¿ as a high temperature type protonic conductor. When the sensor heated at 900 Ž was exposed to air passed through the H2O + D2O mixture at 20 Ž, it could respond to D2O in the concentration range of 5 to 100% with a 90% response time of about 15 min.
—Ñ –L‘qA‚”ö—Y“ñA´…NŽA]“ª ½
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EFFECT OF Y2O3 CONTENT ON HYDROGEN SENSING PROPERTIES OF ZINC OXIDE VARISTOR GAS SENSORS
Feng-Cang LIN, Yuji TAKAO, Yasuhiro SHIMIZU, and Makoto EGASHIRA
Department of Materials Science and Engineering
Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852, Japan
Current-voltage characteristics of two series of ZnO varistors with and without 5.0 mol% Cr2O3 have been investigated as a function of Y2O3 content in air as well as in 1.0 % H2 in the temperature range 400Ž - 600Ž. Every varistor exhibited a shift of breakdown voltage to a lower electric field in the presence of 1.0% H2. For both series of varistors, the magnitude of the breakdown voltage shift (H2 sensitivity) increased with increasing Y2O3 content, then reached a maximum value at 0.25 mol% Y2O3. From the standpoints of the H2 sensitivity and the nonlinearity, the varistor containing 5.0 mol% Cr2O3 and 0.25 mol% Y2O3 was found to be the most promising candidate as a H2 sensor among the varistors tested.
Masanori ANDO, Tetsuhiko KOBAYASHI and Masatake HARUTA
Light and Material Group, PRESTO, JRDC
and Osaka National Research Institute, AIST
l-8-31 Midorigaoka, Ikeda. Osaka 563, Japan
Cobalt oxide (CO3O4) films prepared by organometallic decomposition have been found to show reversible absorbance change in the UV-visible-near IR wavelength region as a function of humidity at room temperature. The humidity-sensitive increase in absorbance of CO3O4 film was most pronounced at wavelengths around 350-400 nm. The reversible absorbance change and the response time within several minutes suggest that the CO3O4 film is potentially applicable to optical humidity
detection.
23.
ƒeƒgƒ‰ƒtƒFƒjƒ‹ƒ|ƒ‹ƒtƒBƒŠƒ“—Þ‚ÌŠ´Ž¼“Á«
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ΊªêC‘å—H
HUMIDITY SENSING CHARACTERISTICS OF TETRAPHENYLPORPHYRIN DERIVATIVES
Takashi Ehara, Makoto Kurosawa, Shinji Nakagomi
and Tatsuo Yamamoto
School of Science and Engineering,
Ishinomaki Senshu University
Ishinomaki, Miyagi, 986-80, Japan
Humidity sensing characteristics of some tetraphenylporphyrin (TPP) metal complexes have been studied. Simple capacitance type elements that use interdigital electrode were fabricated and measured. All elements showed significant sensitivity in high humid air with more than 80 % of relative humidity (RH), by increasing of capacitance. On the contrary, they did not display strong sensitivity in low humidity from 20 %RH to 60 %RH. However, sensing characteristics of the materials in low humidity were different from each other. The element that uses Zn-TPP as sensing material showed better sensitivity than the other element in 60 or 70 %RH. Although the tendency is not remarkable, these materials indicated dependency of sensing characteristics on properties of the central metals in low humidity.
STUDY ON THE OXYGEN SORPTION INTO THE POLYMER COORDINATED METAL COMPLEX FILMS WITH A QUARTZ CRYSTAL MICROBALANCE TECHNIQUE
Tsuyoshi YAMAJl, Yoshihiko SADAOKA Masanobu MATSUGUCHI and Yoshiro SAKAI
Department of Applied Chemistry, Faculty of Engineering
Ehine Univertity, Matsuyama, Ehime 790, Japan
Polymer coordinated (N',N'-Disalicylidene ethylene diamine)cobalt(II) (Co(salen)) complex binds molecular oxygen rapidly and reversibly even in the solid state. In this study, oxygen sorption behavior of poly(4-vinylpyridine) (P4VPy) - Co(salen) complex and poly(octyl methacrylate)-co-(4-vinylpyridine)] (POMPy) - Co(salen) complex was investigated by using a Quartz Crystal Microbalence method. The amount of sorbed oxygen, depends on the concentration of Co(salen) in the film as well as the composition of copolymer as a ligand. The mole ratio of reversibly sorbed oxygen to Co(salen) is high at low concentration of Co(salen) in the film.
DISCRIMINATION OF ALCOHOL BY PATTERN RECOGNITION ANALYSIS OF TRANSIENT RESPONSES MEASURED USING A QUARTZ RESONATOR GAS SENSOR
Hidehito NANTO, Shiro TSUBAKINO, Shigeki KITAGAWA, Masaaki HABARA.
Ruth I. WAITE 1 and Yoshiteru DOUGUCHI 2
EDS Research Laboratory, Kanazawa Institute of Tech.,
7-1 Oogigaoka, Nonoich-machi, P.O.Kanazawa-South, Ishikawa 921, Japan *Rose-Hulman Institute of Tech., 5500 Wabash Avenue,Terre Haute, IN 47803 **lndust. Res. Institute of Ishikawa, 1 Tomizu-machi, Kanazawa, 920-2, Japan
Transient response curves for exposure to aromas which are generated by vaporizing each mixture with different ratio of ethylalcohol to distilled water are observed using an epoxy-coated quartz-resonator gas sensor. The pattern recognition using principal component analysis is carried out using parameters which characterize the transient response curves. The responses for individual aroma tend to cluster in discrete sections of space with well-defined boundaries .
ŽR“c¹OA’艪–F•FAŽðˆä‹`˜Y
ˆ¤ŠÉ‘åH
OPTICAL GAS SENSOR BY USING METHYLCALCEIN-POLYMER COMPOSITES
Masahiro YAMADA, Yoshihiko SADAOKA, and Yoshiro SAKAI
Department of Applied Chemistry, Faculty of Engineering,
Ehime University, Matsuyama, Ehime 790, Japan
For 4-vinylpyridine-styrene-co-polymer composite thin film, fluorescence intensity at ămax=540nm was enhanced by sorption of water and hardly influenced by ammonia vapor. For poly (acrylic acid) composite thin film in humidity ambient, fluorescence intensity at ămax=530nm decreased with increasing ammonia concentrations. For methylcalcein-polymer composite thin films, sensitivity and selectivity for ammonia and humidity depend on acidity/basicity of polymer matrix, and therefore sensitivity and selectivity can be controlled.
OPTICAL CO SENSITIVITY OF CuO/Au FILMS IN THE PLASMON ABSORPTION BAND
Masanori ANDO, Tetsuhiko KOBAYASHI and Masatake HARUTA
Light and Material Group, PRESTO, JRDC
and Osaka National Research Institute, AIST
1-8-31 Midorigaoka, Ikeda, Osaka 563, Japan
Composite films consisting of ultrafine Au particles covered with thin CuO layers have been found to show the optical CO sensitivity. The optical absorption of CuO/Au composite films increases with an increase in CO concentration in air and reversibly recovers in fresh air free of CO. The absorbance change due to CO reached to a maximum in the plasmon band of Au (ă=700-800 nm) and it was enhanced with an increase in temperature. Such an absorbance change may be ascribed to a change in the structure and electronic state of ultrafine Au particles at the contact interface with CuO.
28.
ƒZƒ“ƒT—p‚Ì‚Š´“x‚ÈŒõ“±”g˜H‚ÌŠJ”
’‹Ŗ¯AˆÉ“¡Œö‹IA‘º—ÑáÁs
‰¡•l‘‘åŠÂ‹«Œ¤
A high sensitive and low loss optical waveguide for sensor use
Xiao-Min CHEN, Kiminori ITOH and Masayuki MURABAYASHl
Institute of Environmental Science and Technology, Yokohama National University,
Tokiwadai, Hodogaya-ku, Yokohama 240, Japan
A composite OWG combining a TiO2 film with a K+-doped glass optical waveguide was prepared on one substrate using sputtering in order to realize very sensitive and low loss OWG system for sensors. This OWG system worked as an efficient tapered velocity coupler, and showed relative sensitivity of more than 2000 times per centimeter optical path. Moreover it was stable against UV-irradiation.
29.
ŒÅ’艻pHŽwŽ¦–ò‚É‚æ‚éŠeŽíƒAƒ~ƒ“ƒKƒX‚ÌŒŸ’m
‚”ö—Y“ñAùŒ´—²•FA´…N”ŽA]“ª½
’·è‘åH
DETECTION OF AMINE GASES BY COLOR CHANGES OF ACID-BASE INDICATORS SUPPORTED ON INORGANIC FILMS
Yuji TAKAO, Takahiko SASAHARA, Yasuhiro SHIMIZU and Makoto EGASHIRA
Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852, Japan, Japan
Sensing properties of inorganic films to amine gases have been investigated based on the color changes of acid-base indicators loaded on the films. Among several kinds of silica gel, the best sensing property was obtained by employing spherical silica gel powders with 120 nm in diameter. It has been revealed that the sensitivity depends on the amount of adsorbed water in the film, the pKb value of objective gases and the pH range for the color change observed for acid-base indicators used.
30.
’è“dˆÊ“d‰ðŽ®ƒZƒ“ƒT‚ð—p‚¢‚½CO2ƒKƒX‚ÌŒŸo
Î’n“OA”Ñ“‡“S–çA‚‹´Ÿ
—Œ¤ŒvŠíA—‰»ŠwŒ¤‹†Š*
Detection for Carbon Dioxide by Electrochemical Gas Sensor
Toru ISHIJI, Tetsuya IIJIMA and Katsuo TAKAHASHI*
Riken Keiki Co.Ltd., 2-7-6 Azusawa, Itabashi-ku, Tokyo 174, Japan *The Institute of Physical and Chemical Research(RIKEN), 2-1 Hirosawa,
Wako-shi, Saitama 351-01, Japan
An amperometric sensor based on the pH-dependent reduction of platinum oxide electrode was developed for the detection of carbon dioxide(CO2). The reduction current of the sensor was proportional to the square root of the CO2 gas concentration. The effect of the components of the electrolytic solution was studied to improve the characteristics of the sensor. A linear relationship between the reduction current and the CO2 gas concentration was obtained by addition of hydrogencarbonate to the electrolytic solution. The linear relation can be explained by hydrogen ion generation with dissociation of CO2 in a solution.
ŽR–{^—R”üA‹îêTˆêA–åŠÔãà”VAˆ§â“Nœ\
‘‘å—HE‘‘åÞ—¿‹ZpŒ¤
EVALUATION OF ELECTRODE CHARACTERISTICS OF ALL SOLID STATE POTASSIUM-SELECTIVE ELECTRODE USING POLYPYRROLE/POLYANION COMPOSITE FILM
Mayumi YAMAMOTO, Shin-ichi KOMABA, Toshiyuki MOMMA and Tetsuya OSAKA
Department of Applied Chemistry, School of Science and Engineering *;
Kagami Memorial Laboratory for Materials Science and Technology, Waseda University.
13-4-1 Okubo, Shinjuku-ku, Tokyo 169, Japan
All solid state potassium-selective electrode was constructed by covering with a plasticized poly(vinyl chloride) (PVC) membrane containing valinomycin over to polypyrrole/poly(4-styrensulfonate) (PPy/PSS) composite film. It shows good Nernstian slope of potential response. The potential stability is controlled by selecting the preparation conditions of PPy/PSS composite film. Moreover, the immersion of the under composite film in a KCl solution before forming the upper layer makes the electrode impedance lower.
32.
DRIFT MECHANISM OF SOLID-STATE ION SENSORS WITH ION-SELECTIVE LIQUID MEMBRANE
Yujj Miyahara, Koutarou Yamashita, Satoshi Ozawa and Yoshio Watanabe
Central Research Laboratory, Hitachi Ltd.,
1-280, Higashikoigakubo, Kokubunji, Tokyo 185, Japan
ABSTRUCT
The interface between an ion-selective membrane and a silver-silver chloride electrode was modified with various electrolyte salts to elucidate the drift mechanism of the solid-state ion sensors.The drift characteristics and the EMF shifts were strongly dependent on the concentration of the salt at the interface. This indicates that the shift and the drift of the EMF are completely governed by the electrochemical process at the interface between the ion-selective membrane and the silver- silver chloride electrode. Active ion exchange, and as a result the thermodynamically defined interface are essential for the stable EMF response of the solid-state ion sensor.
ˆÉ“¡‹MŽuA‰““c_ŽiAƒnƒ“ƒi@ƒ‰ƒfƒbƒJ*A’·“ê—³ˆê*A¬“c“ˆ˜a“¿**A”~‘òŠì•v
“Œ‘å—A–k‘å—*A“Œ‘å–ò**
POTENTIOMETRIC RESPONSES TO PHENOL DERIVATIVES AS NEUTRAL SPECIES BY PVC MATRIX LIQUID MEMBRANES BASED ON LIPOPHILIC QUATERNARY AMMONIUM CATIONS AND RELATED SENSORY ELEMENTS
Takashi ITO, Koji TOHDA, Hanna RADECKA*, Ryuichi NAGANAWA*,
Kazunori ODASHIMA**, and Yoshio UMEZAWA
Department of Chemistry, School of Science, The University of Tokyo,
Bunkyo-Ku, Tokyo 113. * Department of Chemistry, Faculty of Science, Hokkaido University,
Kita-Ku, Sapporo, Hokkaido 060, Japan ** Faculty of Pharmaceutical Sciences, The University of Tokyo,
Bunkyo-Ku, Tokyo 113, Japan
Anionic potentiometric responses to phenol derivatives were observed by membranes based on lipophilic quaternary ammonium salts at pH 6.0, at which these guests exist almost exclusively in their uncharged forms. The response slope in a concentration range between 10-3 and 10-2 M of phenol was ca.-70 mV, which was greater than the theoretical value for a monovalent anion according to the Nernst equation (-58.2 mV/decade at 20 Ž). The potentiometric selectivity seems to reflect both logPoct and pK1 value of each phenol derivative, whereas potentiometric responses toward compounds having no phenolic OH group such as cyclohexanol and veratrole were negligible.
Yukinori TANI*, Yoshio UMEZAWA*, Katsumi CHIKAMA**
Akihide HEMMI** and Mitsuyuki SOMA*** * Department of Chemistry, School of Science, The University of
Tokyo, Hongo, Tokyo 113, Japan, ** Department of Chemistry, Faculty of
Science, Hokkaido University, Sapporo 060, Japan, *** National Institute
for Environmental Studies, Tsukuba, Ibaragi 305, Japan
The solubilities of lanthanum fluoride (LaF3) powder and single-crystals were measured in various aqueous electrolyte solutions. In contrast to the classical assumption of the stoichiometric dissolution of LaF3, it was found that the dissolution of the component cation, La3+, was undetectable and the fluoride ion dissolved preferentially: CF > 3 x CLa3+ where C is the ion concentration. X-ray photoelectron spectroscopy (XPS) of the LaF3 surface treated with electrolyte solutions corroborated this observation. As a result of the preferential fluoride dissolution, charge separation was expected to occur in such a way that the LaF3 surface would have positively charged "fluoride vacancies". This was confirmed by changes in membrane potential as a function of the fluoride dissolution and the adsorption of an anionic adsorption marker, Eosin-Y, on the solid surface. It was also found that the preferential dissolution of fluoride ions was accompanied by simultaneous adsorption of almost the same amount of electrolyte anions (e.g. NO3-) onto the LaF3 surface. This was confirmed by both solution measurements and surface analysis by diffuse reflectance IR Fourier transform (DRIFT) spectrometry. The result of this anion adsorption was explained in terms of ion-exchange to ensure electroneutrality in the bulk of the adjacent electrolyte solution, which would otherwise be violated by the preferential fluoride dissolution. The anionic adsorption marker and DRIFT measurements were used to characterize further the above-mentioned ion-exchange and selective uptake of fluoride ions into the "fluoride-vacancies". Release of the adsorbed Eosin-Y or electrolyte anions, such as NO3-, from the LaF3 surface was found to be induced only by F- or OH- ions only. On the basis of the this observation, the response mechanism of the fluoride ion-selective electrodes will be discussed.
¬–ì˜alA‚{—zŽqAŠ_“à@—²Am–ØŽŒÈ
‰¡•l‘‘åH
VOLTAGE-SCAN FLUOROMETRY OF THE FACILITATED ION TRANSFER ACROSS THE OIL / WATER INTERFACE USING FLUOROIONOPHORES
Kazuto ONO, Yoko TAKASU, Takashi KAKIUCHI, Katsumi Niki
Department of physical chemistry, Yokohama National University
Yokohama-shi, Hodogaya-ku, Tokiwadai 156, Japan
Ion-transfer voltfluorometry, which detects the transfer of fluorescent ions in nM level across the liquid-liquid interface, has been extended to the study of non-fluorescent ion transfer by making use of the facilitated transfer of these ions with a fluorescent ionophore, coumarin 153 linked to monoaza-15-crown-5 (C153-crown(O4)). When the concentration of C153-crown(O4) in DCE was 2 ƒÊM and the aqueous phase contained excess amount of alkali-and alkaline earth metal ions, the increase in fluorescence accompanied by the linear scan of the voltage was observed. In alkali ion transfers, the differential voltfluorograms were isomorphic to cyclic voltammograms.
”~àV‘ãŽqA—Ñ@‹Å–¾A¼àV¸ˆêAŠÇŒ´³—YA”~àVŠì•v
“Œ‘勳—{A–k‘å—A“Œ‘å–„
CATION PERMSELECTIVITY IN THE PHASE BOUNDARY OF IONOPHORE-INCORPORATED SOLVENT POLYMERIC MEMBRANES AS STUDIED BY FT-IR ATR SPECTROSCOPY
Kayoko UMEZAWA*, Xiao Ming LIN**, Seiichi NISHIZAWA***,
Masao SUGAWARA*** and Yoshio UMEZAWA*** * Department of Chemistry, College of Art and Science, The University of Tokyo, Komaba, Tokyo 153, Japan, ** Division of Environmental Conservation, Graduate School of Environmental Science, Hokkaido University, Sapporo 060, Japan; *** Department of Chemistry, School of Science, The University of Tokyo, Hongo, Tokyo 113, Japan
Behaviors of permselective membrane transports were studied by FT-IR ATR spectroscopy and potential measurements for the solvent polymeric membranes incorporated respectively with several different ionophores. The stoichiometric ratios between the complexed cations and their corresponding counter anions in the phase boundary, 0.31 - 1.8ƒÊm in depth, of the membrane were determined for each membrane made, beforehand, in contact with various primary ion solutions. When hydrophilic counter anions were used for the primary ion solutions, the IR spectra for the membrane were exclusively from the complexed cations, and no IR-active anionic peak appeared. On the contrary, when a hydrophobic counter anion, SCN-, was used for the primary ion solutions, the spectra from both the complexed cation and corresponding counter anion showed up, of which stoichiometric ratios changed depending on the concentrations of primary ion salts, and on the coexistence of a derivative of tetraphenyl borate in the membrane. The obtained results were discussed in terms of the extent of cation permselectivity and its relevance to the potential response of ionophore-incorporated liquid membrane ion-selective electrodes.
‰““c_ŽiA‹g’Jì^Ži*A”~àVŠì•vA‹´–{ŒP**Aìè¹”Ž**
“Œ‘å–„A–k‘å—*A–k‘å“dŽqŒ¤**
CATION PERMSELECTIVITY AT THE PHASE BOUNDARY OF IONOPHORE INCORPORATED SOLVENT POLYMERIC MEMBRANES AS STUDIED BY OPTICAL SECOND HARMONIC GENERATION (SHG)
Koji TOHDA, Yoshio UMEZAWA, Shinji YOSHIYAGAWA*, Satoshi HASHIMOTO**
and Masahiro KAWASAKI**
Department of Chemistry, School of Science, The university of Tokyo, Tokyo 113, Japan
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060, Japan ** Research Institute of Electronic Science, Hokkaido university, Sapporo 060, Japan
The optical second harmonic generation (SHG) was observed at the surface of various ionophore-incorporated poly(vinyl chloride) (PVC) liquid membranes. The SHG signal of the membrane in contact with the aqueous solution generally increased with increasing primary cation activities in the solution, and then leveled off at higher cation concentrations. The concentration dependence of primary cations as well as the ionophore on the SHG intensities was analyzed based on the Langmuir type adsorption model. When a lipophilic counter anion, SCN-, was used for the primary ion solution, the decreases in the potentiometric and SHG responses were observed in the same concentration region. The improvement in the SHG as well as potentiometric responses was observed with the addition of a lipophilic anionic site into the membrane. These parallel changes in membrane potentials and SHG signals demonstrated allowed us to conclude that the observed membrane potentials are primarily governed by the SHG active oriented species at the membrane surface. However, another important feature of the SHG response is that the saturation occurs with higher cation concentrations where Nernstian potentiometric responses were still observed. The latter results suggest that the SHG inactive complex due to insufficient molecular orientation, locating somewhat membrane interior, also contributes to the membrane potential. To evaluate the contribution of the SHG active oriented complexes to the generation of the ISE potentials, the SHG responses were analyzed on the basis of a space-charge model.
38.
SOSŒ^SPVƒZƒ“ƒT
ˆÉ“¡‘PKAÎìF–¾
V“dŒ³H‹Æ
SPV SENSOR with SOS WAFER
Yoshitaka Ito, Takaaki Ishikawa
Research & Development Center, Shindengen
Hanno-shi, Saitama 357, Japan
A novel integrated surface photovoltage (SPV) sensor system has been investigated by joining a Silicon on Sapphire (SOS) wafer to a visible laser light. The 5 sensors are made on SOS wafer with the thickness of 0.6 ƒÊm and located with 1~1mm2 in area at a 2 mm pitch each to each, covered of Si3N4 layer for pH sensor. The back-side of the sensor is illuminated with the He-Ne laser beams of red and green. The present study indicates that the sensor illuminated by green laser having the wavelength 543.5 nm is superior to achieve a satisfactory position and sensitivity precision without cross-talk between sensing bits to conventional SPV sensors made of Si wafer.
39.
SPV–@‚ð—p‚¢‚½ŠÃ–¡—¿ƒZƒ“ƒT‚ÌŽŽì
²X–Ø–LA“à“cG˜aAŸ•”º–¾
é‹Ê‘åH
FABRICATION OF SWEET DETECTABLE SENSOR WITH SPV METHOD
Yutaka SASAKI, Hidekazu UCHIDA and Teruaki KATSUBE
Faculty of Engineering, Saitama University
255 Shimo-Okubo, Urawa-shi, Saitama 338, Japan
A sweet taste sensor was developed using SPV (surface photo-voltage) technique with polyvinylbutyral resin for the immobilization of ion sensitive material (artificial lipid membrane). A differential SPV method based on a time sharing process, which has been developed in our laboratory[l] , was successfully used to discriminate four kinds of commercially available sugars. It was also shown that the polyvinylbutyral resin has strong adhesion to Si3N4 film leading to the stabilization of sensor response.
¯@—F“TAˆÀÖ‡ˆêA’·@“N˜Y
“Œ–k‘å–ò
PREPARATION OF ENZYME MULTILAYERS BASED ON AN AVIDIN/BIOTIN SYSTEM FOR THE REGULATION OF THE PERFORMANCE OF ENZYME SENSORS
Tomonori HOSHI, Jun-ichi ANZAI and Tetsuo Osa
Pharmaceutical Institute, Tohoku University,
Aobayama, Sendai 980-77, Japan
The multilayer of glucose oxidase (GOx) on platinum (Pt) electrode was prepared by use of avidin and biotinylated GOx and its performance as an amperometric glucose sensor was characterized. An alternate and repeated deposition of avidin and biotinylated GOx gave protein multilayers composed of avidin monolayers and biotinylated-GOx monolayers which are connected with each other through strong affinity between avidin and biotin moieties of the enzyme (binding constant: 1015 M-1). Amperometric response of the glucose sensors constructed by using these enzyme multilayers was controlled stepwise and rather precisely by regulating the number of GOx layers.
ŽO˜aK°A–¢‰i’qˆêA“à“c@—E
“Œ–k‘åH
Permeation and Electrocatalysis at hydrophobically prepared diaphragm electrode and its application to a sensor
Y. Miwa, T. Matsue, and I. Uchida
Department of Molecular Chemistry and Engineering,
Faculty of Engineering, Tohoku University,
Aramaki-Aoba, Aoba-ku, Sendai 980-77, Japan
We here report a new type of a mediated enzyme sensor, where cofactors of enzymes and analytes are separated by a hydrophobically prepared Au or Pt diaphragm electrode. Ethanol in an analyte phase permeated through the diaphragm, and was catalytically oxidized at the electrode coated with diaphorase and alcohol dehydrogenase in a cofactor / mediator phase. No permeation of the cofactor and mediator through the diaphragm was observed.
42.
“d‰ðd‡â‰«ƒ|ƒŠƒsƒ[ƒ‹–Œ‚ð—p‚¢‚½”A‘fƒZƒ“ƒT‚Ìì»
‹îêTˆêA£ŽR—ÏŽqA–åŠÔãà”VAˆ§â“Nœ\
‘‘å–„HE‘‘åÞ—¿‹ZpŒ¤
POTENTIOMETRIC BIOSENSOR FOR UREA USING INSULATING POLYPYRROLE FILM
Shin-ichi KOMABA, Michiko SEYAMA, Toshiyuki MOMMA and Tetsuya OSAKA
Department of Applied Chemistry, School of Science and Engineering *;
Kagami Memorial Laboratory for Materials Science and Technology, Waseda Universisity, *3-4-1 Okubo, Shinjuku-ku, Tokyo 169, Japan
Potentiometric biosensor for urea was prepared by electropolymerization process of pyrrole in an NaHCO3 aqueous solution containing urease (Urs). Urs was entrapped into insulating and electroinactive polypyrrole (PPy) film during electropolymerization, and the selection of the polymerization conditions makes the urea response possible. This PPy(Urs) electrode shows the Nernstian response to urea in Tris buffer solution at 35 Ž. The urea response of the PPy(Urs) electrode is suggested to be due to good pH response of the insulating PPy electrode.
ŽR“c—T”VA´…˜aKA—é–سN
‹ãH‘åî•ñH
CALIBRATION OF ENZYME SENSORS BASED ON FUZZY EXPERT SYSTEM
Hiroyuki YAMADA, Kazuyuki SHIMIZU, and Masayasu SUZUKI
Faculty of Computer Science and Systems Engineering, Kyushu Institute of
Technology, 680-4 Kawazu, Iizuka, Fukuoka 820, Japan
Integrated micro enzyme sensors are required in bioprocess monitoring. The auto-calibration is necessary for the on-line monitoring but it is not easy for micro enzyme sensors because of their frequent abnormal data, narrow linear range, cross-talking and so on. In this study, an intelligent calibration method was developed by using a fuzzy expert system. Based on "expert information" obtained from the data of preliminary experiments, the membership functions were determined. The relationship between sensor outputs and concentrations was described by these membership functions. The present method could eliminate abnormal data and required only a short time for the calculation.
—Ñ“c‹§ŽjA‰ª–{‘å‰îArì„
‹ß‘å‹ãBH
SURFACE PLASMON RESONANCE STUDY FOR THE DETECTION OF SOME PROTEIN
Tadashi HAYASHIDA, Daisuke OKAMOTO
and Tsuyoshi ARAKAWA
Department of Industrial Chemistry, Faculty of Engineering Kinki University in Kyushu,
Iizuka-shi, Fukuoka 820, Japan
The detection of cytochrome C has been investigated by an optical chemical sensor based on laser-excited surface plasmon resonance. When the medium outside was changed from air to the cytochrome C solution (cytochrome C (100ƒÊM) + 0.1M PBS (KH2PO4:Na2HPO4=l:2, pH7.06) , the resonance angle first varied from 23.08‹ to 52.01‹, followed by increasing to a constant value (52.51‹) . In the use of the sensor head of which a silver thin film was coated by a Nafion thin film , the shift of incident angle was also observed by the incorporation of cytochrome C into Nafion thin film .
45.
·“®Œ^•\–ÊŒõ“dˆ³‘ª’è–@‚É‚æ‚é–ƉuƒZƒ“ƒT‚Ì‚Š´“x‰»
Šy@ŠC–FA²X–Ø–LA“à“cG˜aAŸ•”º–¾D
鉤‘åH
HIGH SENSITIVE IMMUNO-SENSOR USING A DIFFERENTIAL SURFACE PHOTOVOLTAGE MEASUREMENT TECHNIQUE
Yueh Hai Feng, Yutaka SASAKI, Hidekazu UCHIDA
and Teruaki Katsube
Department of Information and Computer Sciences,
Faculty of Engineering, Saitama University
255 Shimo-okubo, Urawa, 338, Japan
New measurement methods of surface photo-voltage (SPV) technique - phase shift method and differential SPV - were developed to fabricate a high sensitive immuno-sensor. It was first shown that the phase shift method, which is based on the detection of phase shift of the surface photo-current, made it possible to detect neutral charge material as well as charge density of the electrode surface.
It was also shown that the differential SPV method increases the signal to noise ratio of the system both of phase shift method and surface potential measurement method leading to the fabrication of a high sensitive immuno-sensor.
‰F“c‘׎OA¬—Ñ—˜ÍAˆê“ñŽOŒb”üA´…_•ã
L“‡Œ§—§‘嶕¨Ž‘Œ¹
DEVELOPMENT OF IMMUNOAFFINITY AIDS SENSOR(‡T) DETECTION OF ENVELOPE PROTEIN gp41 ANTIGEN AND ANTIBODY
Taizo UDA, Toshiaki KOBAYASHI, Emi HIFUMI, and Kousuke SHIMIZU
School of Bioresources, Hiroshima Prefectual University,
Shoubara-shi, Hiroshima 727, Japan
A monoclonal antibody for the conservative region of gp41 was produced and then the antigen determining site was analyzed by means of epitope mapping in order to obtain the suitable affinity peptide for construction of an immunoaffinity AIDS sensor. The peptide having slightly less immunoaffinity, EGIEE, was the most preferable. EGIEE was labeled with catalase and used as a mimic antigen which had been bound to the fixed antibody on immuno-membrane prior to the sensing by an oxygen electrode. The mimic antigen was replaced by gp41, generating some oxygens in proportion to the concentration of gp41. On the other hand, anti gp41 antibody was also detected using a mimic antibody chemically modified with polyethylene glycol.
…’J•¶—YA–ê
¶–½HŒ¤
HIGHLY-SENSITIVE MEASUREMENT OF CATECHOLS USING CARBON FELT ELECTRODE IMPREGNATED WITH GLUCOSE OXIDES-CONTAINING SOLUTION
Fumio MIZUTANI and Soichi YABUKI
A carbon felt electrode impregnated with a glucose oxidase / glucose-solution was used for measuring dihydroxyphnols (e.g., catechol and dopamine). Dihydroxyphenol molecules are oxidized but regenerated by the enzymatic reaction. The consumption/ regeneration cycle for dihydroxyphenols resulted in an amplified electrode response. Further, the measuring method could be free from the electrochemical interference by oxidizable species such as L-ascorbic acid.
Ÿ@FAŽR’†OŽiAXiurong Yang*AGarry A. Rechnitz*
‰ªŽR‘å–òAƒnƒƒC‘åƒoƒCƒIƒZƒ“ƒTŒ¤*
DEVELOPMENT OF BIOSENSORS RESPONDING TO ADENOSINE-5'-TRIPHOSPHATE (ATP)
Takashi KATSU, Koji YAMANAKA, Xiurong YANG* and
Garry A. RECHNITZ*
Faculty of Pharmaceutical Sciences, Okayama University,
Tsushima, Okayama 700, Japan and *Hawaii Biosensor
Laboratory, Department of Chemistry, University of Hawaii,
Honolulu, HI 96822, U.S.A.
New amperometric and potentiometric biosensors responding to adenosine-5'-triphosphate (ATP) were constructed. The amperometric biosensor was designed using a platinum-dispersed carbon paste into which glycerol kinase and glycerol-3-phosphate
oxidase were incorporated. The biosensor is based on the detection of hydrogen peroxide produced by the enzymatic reaction of ATP with glycerol and the subsequent oxidation of glycerol-3-phosphate. The use of the platinum-dispersed carbon paste electrode lowered the oxidation potential for hydrogen peroxide. The potentiometric method used a choline-sensitive membrane electrode and choline kinase enzyme. Choline reacted with ATP to produce the electrode-insensitive choline phosphate and, therefore, the concentration of ATP could be determined by the measurement of choline consumed by the enzymatic reaction.
²“¡¶’jA–Ø‘º@oA–îŒûGÍ
_“ÞìH‘å
CALORIMETRIC BIOSENSING OF ZINC(II) IONS USING AN IMMOBILIZED THERMOLYSIN
lkuo SATOH, Izuru KIMURA, and Hideaki YAGUCHI
Department of Chemical technology, Faculty of Engineering,
Kanagawa Institute of Technology
1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken, 243-02, Japan
Calorimetric biosensing of zinc(II) ions was tested with use of thermolysin covalently immobilized on porous glass beads. The biosensing system was assembled with the beads-containing column mounted in a flow-injection calorimetric device for monitoring the enzyme activity. Change in temperature at the outlet of the column was successively detected and recorded. The metal-free enzyme (apoenzyme) was regenerated by exposing EDTA solution(pH 4.0) to the column. Zinc(II) ions in submillimolar levels were determined through the activation of the immobilized apoenzymes.
Tomohisa NIIMI, Tetsuya HARUYAMA, Eiry KOBATAKE. Yoshihito IKARIYAMA, aud Masuo AIZAWA
Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology
For the sensitive and rapid detection of environmental pollutants, we have made a recombinant E.coli transformed with a plasmid pTSN316 containing a gene for luciferase and the promoter region of TOL plasmid. As luciferine, the substrate of luciferase, was difficult in permeating to through E.coli membrane, it took considerably longer time to get a sufficient luminescence. In the present study, the permeability of luciferine through E.coli membrane was enhanced in acidic conditions. The optimum pH was found to be around 4.5. m-Xylene was determined in the concentration range from 5ƒÊM to 0.5ƒÊM at pH 4.8.
51.
ƒoƒCƒIƒZƒ“ƒT‚ð—p‚¢‚½¬”ž‚̃Aƒ~ƒ‰[ƒ[Šˆ«‚Ìv‘¬‘ª’è
”‹–ì’J—²ˆêAŽðˆä‹vmŽqAˆÀˆä’å•vA¬¼—²A²X–ØãàA–î–ì˜a‹`A’r‘܈ê“TAçj•”ª•v
“Œ‘åæ’[Œ¤A“ú´»•²
RAPID MEASUREMENT OF AMYLASE ACTIVITY IN WHEAT FLOUR USING BIOSENSOR METHOD
Ryuichi HAGINOYA, Kuniko SAKAI, Sadao YASUI, Takashi KOMATSU, Satoshi
SASAKI, Kazuyoshi YANO, Kazunori IKEBUKURO and Isao KARUBE
Research Center for Advanced Science and Technology, University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan
Technical Research Center, Nisshin Flour Milling Co., Ltd.
5-3-1 Tsurugaoka, Oi-machi, Iruma-gun, Saitama 356, Japan
Amylase activity in wheat flour is very important indicator for evaluating baking quality of wheat flour. One of the conventional method for the measurement of amylase activity in flour is an amylograph which is one of viscometers. However, the data from the amylograph are only characteristic curves of scalded flour. In this study, we have developed a quick and easy measurement method of amylase activity in wheat flour using a flow injection analysis (FIA) type biosensor system. And the amylase activity measured by the biosensor method was compared with that obtained by commercial measurement kit. Good correlation was obtained between the biosensor method and the measurement kit method.
’d@‹à@AŽR–{MŽqA…’J•¶—Y*A–ê*
ƒeƒNƒmƒƒfƒBƒJŠJ”ƒZƒ“ƒ^[E¶–½HŒ¤*
AMPEROMETRIC MALTOSE-SENSING ELECTRODE BASED ON LIPID-MODIFIED GLUCOSE OXIDASE AND ƒ¿-GLUCOSIDASE
Jinzong TAN, Shinko YAMAMOTO, Fumio MIZUTANI* and Soichi YABUKI*
Research and Development Center, Techno Medica Co. Ltd., East Building 502 of
Kanagawa Science Park (KSP), Takatsu-ku, Kawasaki, Kanagawa 213, Japan * National Institute of Bioscience and Human Technology, 1-1 Higashi, Tukuba, Ibaraki 305, Japan
A maltose-sensing electrode was developed by using lipid-modified enzymes, glucose oxidase and ƒ¿-glucosidase : first, a platinum base electrode was dipped into a benzene solution containing these modified enzymes and dried, and second, the electrode was dipped into Kodak AQ-29D polymer solution and dried. The electrode thus obtained had a response time of 15 seconds and a linear response from 0.01 to 2.0 mM for maltose. The electrode could be used for two weeks.
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INSTALLATION OF INTELLIGENT MECHANISMS INTO MATERIALS THEMSELVES
Hiroaki YANAGIDA
Faculty of Engineering
Environmental Science Center,
University of Tokyo,
Hongo, Bunkyo-ku, Tokyo 113, Japan
The essential purpose to develop intelligent materials is to aboid spaghetti syndrome of technology. Keywords are wisdom, integration of structural performance and functional behavior, tecology,etc. One of the most important cases is to assure reliability of large structures. This is only achieved to make materials strong enough and diagnose themselves. Design of self-diagnosis is explained in this paper.
MOLECULAR BEADING OF LUMINOUS MICROORGANISM HAVING A SPECIFIC PURPOSE AND ITS APPLICATION TO MONITOR HARDLY DECOMPOSABLE CHEMICAL COMPOUNDS IN THE ENVIRONMENT
Yoshihito IKARIYAMA
Research Institute of National Rehabilitation Center for the Disabled
4-1 Namiki, Tokorozawa, Saitama 359, Japan
Eiry KOBATAKE, Masuo AIZAWA
Department of Bioengineering, Tokyo Institute of Technology
4259 Nagatsuda, Midori-ku, Yokohama. Kanagawa 227, Japan
A new strategy toward the detection of aromatic hydrocarbons such as benzene (B), toluene (T), and xylene (X) with a recombinant E.coli has been taken. We have constructed a new plasmid (pTSN316) for light generation. A fragment from TOL plasmid, responsible for the digestion of BTX and their derivatives, bearing the promoter (Ps) of the xyl S gene for a transcriptional activator, was fused to the luciferase gene of firefly (Photinus pyralis) . The E. coli strain containing the plasmid (HB101(pTSN316)) can emit photons in the presence of a benzene derivative. The xyl R regulatory gene of TOL plasmid plays an important role to induce luciferase. The bioluminescence of the transformed E. coli increased with the increase in BTX concentration. When compared at 0.8 or 0.9 mM concentration, the bioluminescence became smaller in order of m-xylene. p-xylene, toluene. and benzene. This indicates that specific binding the regulatory protein, Xyl R, and BTX is very important. Moreover, we made a monitoring devise by immobilizing the recombinant E. coli to the tip of a fiber optic, and tried to measure BTX concentration in a batch system. In this result, several ppm of BTX was measured.
@These findings suggest that realtime monitoring of BTX is possible. And the aromatic hydrocarbon concentration can be easily measured by using the proposed fiber optic device. We believe that substances which cause environmental deterioration can be sensitively monitored in this method.
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