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English Contents複合固定化酵素を用いた新規ヒアルロン酸分析法の開発
神奈川工科大学・応用バイオ科学科、ジュジュ化粧品（株）＊
○飯田泰広、長嶋久美子、山村 晃、松本邦男、中村行雄＊
Development of novel method for hyaluronic acid sensing
with use of multi immobilized enzyme column
Yasuhrio IIDA, Kumiko NAGASHIMA, Akira YAMAMURA,
Kunio MATSUMOTO and Yukio NAKAMURA＊
Department of Applied Bioscience, Faculty of Applied Bioscience,
Kanagawa Institute of Technology
1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken, 243-0292
＊Research & Development, JUJU Cosmetics Co., Ltd.,
5-31-2 Tomuro, Atsugi, Kanagawa, Japan
A determination method for hyaluronic acid based on a photometric flow-injection system by evaluating the activity of an immobilized hyaluronidase was developed and the properties were investigated. The hyaluronidase activity was photometrically evaluated by using a double-layered column which consisted of N-acylhexosamineoxidase and peroxidase. Phosphate buffer (0.1 M, pH 6.0) as a carrier solution was continuously pumped through the system, and sample solutions (hyaluronic acid) were introduced into the system via rotary injection valves. The hyaluronic acid solution was catalyzed by the hyaluronidase and the products was oxidized by N-acylhexosamineoxidase and the produced H2O2 reacted with DAOS (N-ethyl-N-(2-hydroxy- 3-sulfopropyl) -3,5-dimethoxyaniline) and 4-AA (4-aminoantipyrine) by peroxidase. The Blue compound produced by the series of the reactions was measured by flow type photometer. Hyaluronic acid in 10 μg/mL was detected by using the system based on the multi immobilized enzyme column.
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イリジウム－ニッケル二元系合金を用いた
トランスデューサの特性解析とそれを用いた応用
NEC グリーンイノベーション研究所a、
物質・材料研究機構 環境・エネルギ－材料萌芽ラボb、
物質・材料研究機構 燃料電池材料センターc
○松本 達a、佐多直明a、御手洗容子b、小林 清c
A NOVEL AMPEROMETRIC TRANSDUCER ELECTRODE WITH IRIDIUM-NICKEL BINARY ALLOYS
Toru Matsumoto a, Naoaki Sata a, Yoko Yamabe-Mitarai b, Kiyoshi Kobayashi c
a Green Innovation Research Laboratories, NEC Corporation,
34 Miyukigaoka, Tsukuba, Ibaraki, 305-8501
b Exploratory Materials Research Laboratory
for Energy and Environment Platinum group metals Group, NIMS,
Sengen 1-2-1, Tsukuba, Ibaraki, 305-0047
c Hydrogen Purification Materials Group, NIMS,
Sengen 1-2-1, Tsukuba, Ibaraki, 305-0047
We have discovered that an Ir-75Ni binary alloy more effective oxidizes hydrogen peroxide than Ir, Ir-5Ni, Ir-25Ni, Ir-50Ni or Ir-85Ni, and developed a novel biosensor employed a working electrode of the Ir-75Ni binary alloy. The five Ir-Ni alloys, Ir, Ni, and Pt were used as their working electrodes fabricated with an arc-melting method, and evaluated their cyclic voltammetry. For fabrication of three glucose biosensors of them, we coated the Ir, Ir-75Ni and the Pt electrodes first with 1 v/v% 3-aminopropyltriethoxysilane [3-APTES] and then with cross-linked 20 w/v% bovine serum albumin and 1 v/v% glutaraldehyde containing 189.4 U/μl glucose oxidase. Tests of the Ir-75Ni electrode demonstrated excellent hydrogen peroxide detecting capability on around 0.7 V constant potential among the five alloy electrodes, the Ir electrode, and the Ni electrode. Other tests of glucose sensors with the Ir, Ir-75Ni electrode and the Pt electrode demonstrated glucose detecting capability was the Pt glucose sensor, the Ir-75Ni glucose sensor, and the Ir glucose sensor in that order: 0.681 μA/mm2 Pt sensor for 2.78 mM; 0.580 μA/mm2 Ir-75Ni sensor for that; and 0.301 μA/mm2 Ir sensor for that.
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電解デバイスを備えたフロー式酵素リアクターの試作
神奈川工科大
○佐藤 生男 a)、村越 誠也 a)、恩田 健司 a)、飯田 泰広 b)
FABRICATION AND TESTING OF AN ENZYME REACTOR ARMED WITH AN ELECTROLYTIC DEVICE
Ikuo SATOH a), Seiya MURAKOSHI a), Kenji ONDA a) and Yasuhiro IIDA b)
a) Department of Applied Chemistry, Faculty of Engineering,
b) Department of Applied Bioscience, Faculty of Applied Bioscience,
Kanagawa Institute of Technology,
1030 Shimo-Ogino, Atsugi-shi, Kanagawa-ken 243-0292
An enzyme reactor armed with an electrolytic device was fabricated and tested for flow-injection analysis of heavy metal ions based on the apoenzyme reactivation methods. In the flat type of enzyme reactor, a constant direct current at 2 mA could be applied without observation of significant evolution of any gases.
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カーボンナノチューブを基盤とする酵素センサ動作の低電位化
芝浦工大工
○星野 達也、井上 貴博、六車 仁志
ENZYME SENSOR WITH CARBON NANOTUBE FOR LOWER POTENTIAL DETECTION
Tatsuya HOSHINO, Takahiro INOUE, and Hitoshi MUGURUMA
Shibaura Institute of Technology, Toyosu, Koto-ku, Tokyo 135-8548
We report on an amperometric biosensor that is based on carbon nanotubes (CNT) and plasma-polymerized film (PPF).A simple and reliable dry-chemical based layer-by-layer process was employed for device fabrication according to the following procedure: (1) a 10-nm-thick acetonitrile PPF layer (first PPF layer) was formed on a sputtered gold electrode;(2) a solution cast CNT layer was formed on the first PPF layer; (3) the CNT layer was treated by nitrogen plasma; (4) Dimethyl amino methyl ferrrocene (DMAMFc) as a electron transfer mediator layer was formed onto the CNT layer;(5) a solution cast glucose oxidase (GOx) layer was formed onto the electron transfer mediator layer;(6) immobilized GOx was overcoated with a 20-nm-thick acetronitrile PPF layer (second PPF layer).The resulting device showed that the oxidizing current response due to enzymatic reaction was 4 to 16-fold larger than that with only CNT or PPF, showing that the PPF and/or plasma process is an enzyme-friendly platform for designing electrochemical communication from the reaction center of GOx to the electrode via CNTs. DMAMFc PPF reduced the polarized potential from +0.8 V down to +0.4 V.
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新型金電極チップを用いるフェニルアラニンセンサの開発
富山大院理工a、富山県立大工b
○三浦将典a、篠原寛明a、須加 実a、浅野泰久b
DEVELOPMENT OF A PHENYLALANINE SENSOR USING A NEWLY DESIGNED GOLD ELECTRODE CHIP
Masanori MIURA a, Hiroaki SHINOHARA a, Minoru SUGA a and Yasuhisa ASANOb
a Graduate School of Science and Engineering, University of Toyama,
3190 Gofuku, Toyama 930-8555
b Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398
Phenylalanine (Phe) is an important essential amino acid and a biomarker of phenylketonuria. Blood Phe is usually detected by HPLC analysis or enzymatic analysis, however, they are still not rapid. We have previously developed a Phe sensor with a gold disk electrode on which PheDH and diaphorase (DI) were co-immobilized. In this study, a newly designed disposable enzyme electrode chip for Phe detection in practical use was prepared. Chronoamperometry using the prepared enzyme electrode chip demonstrated the increase of the catalytic oxidation current depended on the concentration of Phe. Detection range of this sensor for Phe was from 20 to 200 μM. This sensor may be applicable to monitor Phe in blood samples.
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ロイシン脱水素酵素を用いる分岐鎖アミノ酸センサの開発とその特性
富山大院理工
○堀江 肇、篠原寛明、寺村一孝、須加 実
DEVELOPMENT AND CHARACTERIZATION OF THE SENSOR
FOR BRANCHED CHAIN AMINO ACIDS DETECTION
USING LEUCINE DEHYDROGENASE
Hajime HORIE, Hiroaki SHINOHARA, Kazutaka TERAMURA, Minoru SUGA
Graduate School of Science and Engineering, University of Toyama,
3190 Gofuku, Toyama 930-8555
Branched chain amino acids (BCAA), including valine, leucine, isoleucine are very important essential amino acids for our body and a biomarker for maple syrup urine disease.From these backgrounds, the development of a biosensor for detecting BCAA is required. We have previously fabricated a BCAA sensor with a gold disk electrode (d=1.6 mm) on which leucine dehydrogenase (LeuDH) and diaphorase (DI) were co-immobilized. Dependence of the sensor response on the concentration of Leu, amino acid selectivity, and pH dependence of this enzyme disk electrode was investigated. In this study, we developed the BCAA sensor for practical use with a new disposable screen-printed gold electrode chip (d=3.0 mm) on which LeuDH and DI were co-immobilized. We also studied about dependence of the sensor response on the concentration of Leu, amino acid selectivity, and pH dependence.
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Bioelectrocatalytic flow detector for H2O2
using coadsorbed HRP
and thionine on carbon felt
Yue WANG a,b and Yasushi HASEBE a,c
a Department of Materials Science and Engineering,
Graduate School of Engineering, Saitama Institute of Technology,
Fukaya-shi, Saitama 369-0293, Japan
b School of Chemical Engineering, University of Science and Technology Liaoning,
Anshan, Liaoning , 114044, China
c Department of Life Science and Green Chemistry,
Saitama Institute of Technology, Fukaya-shi, Saitama 369-0293, Japan
Horseradish peroxidase (HRP) and thionine (TN) were co-adsorbed onto the carbon felt (CF) surface from mixed solution of HRP and TN. The resulting HRP and TN co-adsorbed CF (HRP/TN-CF) was used as a working electrode unit of bioelectrocatalytic flow-through detector for H2O2. Cyclic voltammetry (CV) and constant potential amperometry revealed that co-adsorbed TN was essential to facilitate the direct electron transfer (DET) between the HRP active center and the CF electrode surface. In order to obtain the highest sensitivity, adsorption conditions (i.e., HRP concentration, ionic strength, adsorption time, pH, and effect of ultrasonic treatment) were optimized. Under the optimized adsorption conditions, the HRP/TN-CF-based H2O2 flow detector exhibited highly sensitive and stable response to H2O2 (linear range, 0.1 to 10 μM; detection limit, 7.9 nM, Kmapp, 30.8 μM; Imax 175.4μM).
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新規脱水素酵素を用いた直接電子移動型フコースセンサの開発
東京農工大院工a、 東大院農b、 東京農工大院農c
○中村暢文a、犬飼 岬a、松村洋寿b、吉田 誠c、五十嵐圭日子b、鮫島正浩b、大野弘幸a
DEVELOPMENT OF A DIRECT ELECTRON TRANSFER TYPE FUCOSE SENSOR USING NOVEL DEHYDROGENASE
Nobuhumi NAKAMURA a, Misaki INUKAI a, Hirotoshi MATSUMURA b, Makoto YOSHIDA c, Kiyohiko IGARASHI b, Masahiro SAMEJIMA b, and Hiroyuki OHNO a
a Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588
b Department of Biomaterials Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 111-8657
c Department of Environmental and Natural Resource Sciences, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509
L-Fucose has been used as the marker of cancers because its concentration increases in patients. However, traditional methods for determining L-fucose have some drawbacks. Electrochemical techniques could be useful for determining L-fucose. Recently, we cloned and heterogeneously expressed L-fucose dehydrogenase from basidiomycete Coprinopsis cinerea (FcDH) which has a catalytic site and a cytochrome b domain as a redox site. In this study, we have constructed a direct electron transfer (DET) -type amperometric L-fucose biosensor using this novel FcDH. The DET catalytic oxidation of FcDH was observed in the cyclic voltammetry in the presence of 50 mM L-fucose by using the FcDH-modified electrode. The calibration curve was obtained from amperometric measurements using the FcDH-modified rotating disk electrode. The current response exhibited Michaelis-Menten behavior and the apparent Michaelis constant was calculated 12.5 mM from the curve. The calibration curve showed good linearity in the range of L-fucose concentration from 0.1 mM to 1.0 mM (r = 0.9994) and from 0.01 mM to 0.1mM (r = 0.9995).
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機能化生体分子を利用する新規バイオセンサの開発
埼玉工大工
長谷部靖
DEVELOPMENT OF HIGHLY FUNCTIONALIZED BIOSENSORS USING FUNCTIONALIZED BIOMOLECULES
Yasushi HASEBE
Department of Life Science and Green Chemistry,
Saitama Institute of Technology
Fukaya-shi, Saitama 369-0293
We have developed high performance biosensors using functionalized biomolecules and their novel catalytic activities. These biosensors can be divided into three categories; (1) highly sensitive oxidase-biosensors based on reducing reagent-induced substrate recycling from oxidized products and enzymatic-intermediates, (2) novel biosensor based on exogenous ligands-induced novel catalytic activity of copper-proteins (i.e., monoamine oxidase and galactose oxidase), and (3) novel biosensors using enzyme-mimic biopolymer-metal complexes such as poly(amino acid)/Cu(II) complex and DNA/Cu(II) complex.
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酵素生成物の変換濃縮を用いた高感度免疫計測法の開発
兵庫県立大院物質理a，JST-CRESTb
○安川智之a,b、吉本芳美a、後藤卓也a、水谷文雄a
DEVELOPMENT OF SENSITIVE IMMUNESENSING SYSTEM BASED ON CHEMICAL ACCUMULATION OF PRODUCTS GENERATED BY ENZYME REACTION
Tomoyuki YASUKAWA a,b, Yoshimi YOSHIMOTO a, Takuya GOTO a and Fumio MIZUTANI a
a Graduate School of Material Science, University of Hyogo,
3-2-1, Kouto, Kamigori, Ako, Hyogo 678-1297
bJST-CREST, 5, Sanbancho, Chiyoda, Tokyo 102-0075
The sensitive electrochemical immunosensing system we report here is based on chemical amplification and charge accumulation. Carcinoembryonic antigen (CEP) and anti-CEA antibody β-galactosidase (β-gal) conjugated was captured to the anti-CEA antibody immobilized on polystyrene microparticles to form the immune-complexes. For the signal amplification, the products generated by the enzyme trapped via immunoreactions were converted to the silver metal particles on the electrode through the electrochemical cell reactions. Electrochemical cell was constructed using the interdigitated array electrode (IDA) for oxidizing 4-aminophenol (PAP) generated by β-gal and grassy carbon electrode for reducing the silver ions. IDA electrode was also used to reduce the oxidized form of PAP generated by the half cell reaction for PAP oxidation.
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バイオナノ磁性粒子を用いた血清中の自己抗体検出技術の開発
東京農工大院工a、医学生物学研究所b
○吉野知子a、内山 諒a、米山健太郎a、堀部卓郎b、久原基樹b、松永 是a
DEVELOPMENT OF A NOVEL METHOD FOR DETECTION
OF AUTOANTIBODY IN SERUM USING
NANO-SIZED BACTERIAL MAGNETIC PARTICLES
Tomoko YOSHINO a, Ryo UCHIYAMA a, Kentaro YONEYAMA a, Takuro HORIBE b, Motoki KUHARA b and Tadashi MATSUNAGA a
a Department of Biotechnology, Tokyo University of Agriculture and Technology,
Koganei-shi, Tokyo, 184-8588
b Medical and Biological Laboratories Company Ltd.,
Ina-shi, Nagano 396-0002
Thyroid stimulating hormone receptor (TSHR) is the target autoantigen in autoimmune thyroid disease, and the level of TSHR autoantibody (thyroid stimulating antibodies, TSAb) in serum is generally measured by enzyme-linked immunosorbent assay (ELISA) using TSHR as an immobilized antigen on the plates in diagnosing Graves’ disease. Preparation and immobilization of TSHR are frequently complicated and time-consuming. In this study, autoantigen, TSHR was displayed onto nano-sized bacterial magnetic particles (BacMPs), and TSAb was detected by using the BacMPs. Ectodomain of human TSHR (1～415 aa, TSHR415) were fused to the C-terminal domain of Mms13, which was isolated as a protein tightly bound to BacMP magnetite, and expressed onto BacMPs produced by Magnetospirillum magneticum AMB-1. Expression of Mms13-TSHR415 fusion proteins was confirmed, and binding activity to thyroid stimulating hormone (TSH) was shown. Futehrmore, competitive binding assay to TSHR415 displayed on BacMPs was performed using alkaline phosphatase(AP) conjugated TSH as a competitor. Inhibition curves were evaluated by the decrease in luminescence intensity resulting from the enzymatic reaction of AP, and sufficient detection range (0.4～30.0 IU/L of TSAb) was shown. The overall simplicity of this assay results in a method that can be easily adapted to a high throughput format.
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マイクロウェルを用いた目的抗体の電気化学的検出デバイスの開発
東北大院環境
○渡部剛志、伊野浩介、珠玖 仁、末永智一
ELECTROCHEMICAL DETECTION OF SPECIFIC ANTIBODIES
USING MICROWELL ARRAY CHIPS
Tsuyoshi WATANABE, Kosuke INO, Hitoshi SHIKU, and Tomokazu MATSUE
Graduate School of Environmental Studies, Tohoku University, Sendai, 980-8579
In recent years, monoclonal antibodies that recognize specific antigens of interest have been used as therapeutic agents and as tools for biomedical research. Discovering a monoclonal antibody requires retrieval of an individual hybridoma from polyclonal mixtures of cells producing antibodies with a variety of specificities. In this study, poly- dimethylsiloxane (PDMS) microwell array chips and polystyrene substrates were used for rapid detection of antibodies that were produced by B-cells. We loaded rat B-cell hybridoma (R4-6A2) suspension into the wells and put the detection substrate onto the wells. After incubation, the substrate was slipped off and were stained with secondary antibody. The substrate surface was observed by fluorescent and electrochemical imaging systems.
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エピジェネティクス計測評価チップの研究開発（II）
DNAメチル化標準試料の分離アッセイ
産総研健康工学a、近畿能開大産業化学b、産総研計測標準c、産総研バイオメディカルd
○脇田慎一a、宮道 隆a,b、藤井紳一郎c、高津章子c、加藤 大d、丹羽 修d
R & D OF BIOCHIP FOR EPIGENETICS（Ⅱ）
ON-CHIP SEPARATION ASSAY OF DIGESTED DNA METHYLATED
STANDARD-SAMPLES
Shin-ichi WAKIDA a, Takashi MIYADO a,b, Shin-ichiro FUJII c,
Akiko TAKATSU c, Dai KATO d and Osamu NIWA d
a Health Research Institute,
National Institute of Advanced Industrial Science and Technology (AIST),
Midorigaoka 1-8-31, Ikeda, Osaka 563-8577
b Department of Industrial Chemistry, Kinki Polytechnic College,
National Institute of Advanced Industrial Science and Technology (AIST),
Inaba 1778, Kishiwada, Osaka 596-0103
c National Metrology Institute of Japan (NMIJ),
National Institute of Advanced Industrial Science and Technology (AIST),
Umezono 1-1-1, Tsukuba, Ibaragi 305-8563
d Institute for Biological Resources and Functions,
National Institute of Advanced Industrial Science and Technology (AIST),
Higashi 1-1-1, Tsukuba, Ibaragi 305-8566
Cytosine methylation is one of the well-known epigenetic mechanisms. Since, some kinds of cancer are closely associated with cytosine methylation, determination of the degree of cytosine methylation in a specific target locus would be highly valuable in diagnosis of cancers. We have studied a rapid separation assay for the degree of cytosine methylation using electrophoretic Lab-on-a-Chip. In this paper, we report a preliminary study of the direct separation between methylcytosine and cytosine in digested DNA sample including nuclease. In order to optimize a separation conditions, some kinds of running buffer were investigated. Among the running buffer, a phosphate buffer was selected by considering the separation of methylcytosine, nucleotide and nuclease. In addition, the concentration of cetyltrimethylammonium chloride (CTAC) and methylcellulose (MC) were also investigated. As a result, good separations of methylcytosine and cytosine in digested 33 mer single stranded DNA sample were achieved within 12.5 seconds without off-line nuclease separation on electrophoretic Lab-on-a-Chip using the optimized running buffer merged with 100 mM phosphate buffer, 15 mM CTAC and 0.001% MC.
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循環腫瘍細胞の迅速検出に向けたマイクロデバイスの開発
東京農工大院工
○細川正人、新垣篤史、吉野知子、田中 剛、松永 是
DEVELOPMENT OF MICROFLUIDIC DEVICE FOR RAPID DETECTION
OF CIRCULATING TUMOR CELLS
Masahito HOSOKAWA, Atsushi ARAKAKI, Tomoko YOSHINO,
Tsuyoshi TANAKA and Tadashi MATSUNAGA
Department of Biotechnology, Tokyo University of Agriculture and Technology,
Koganei-shi, Tokyo 184-8588
Circulating tumor cells (CTCs) are tumor cells circulating in the peripheral blood of patients with metastatic cancer. In this research, a microfluidic device equipped with a size-selective microcavity array for highly efficient and rapid detection of CTCs from whole blood was developed. The device enabled specific separation of tumor cells from whole blood according to the size and deformability differences between tumor cells and hematologic cells. In previous techniques, CTCs are enriched using magnetic beads coated with monoclonal antibodies targeting epithelial cell markers. This method is time consuming and cell recovery efficiency is relatively low. Our method using the device equipped with the size selective microcavity array results over 90% of recovery efficiency in a high throughput manner. Moreover, the recovered living cells can be used for further cellular analyses such as tumor marker screening. The device equipped with the size selective microcavity array will be used as a compact, cost-efficient and simple tool for early diagnoses of metastatic cancers. This should allow us to make diagnoses after surgery and to evaluate a risk from metastasis development. This cell analysis technique has further potential as a valuable and widely applicable tool for studies on gene screening and expression analyses of various kinds of cells.
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２次元フォトセンサアレイの白血球機能解析への応用
東京農工大院生命a、早稲田大スポーツ科学b
○須永吉彦a、田中 剛a、鈴木克彦b、松永 是a
DEVELOPMENT OF LEUKOCYTE ANALYSIS SYSTEM
USING TWO-DIMENSIONAL PHOTOSENSOR ARRAY
Yoshihiko SUNAGA a, Tsuyoshi TANAKA a, Katsuhiko SUZUKI b
and Tadashi MATSUNAGA a
a Department of Biotechnology, Tokyo University of Agriculture and Technology,
Koganei-shi, Tokyo 184-8588
b Faculty of Sport Sciences, Waseda University,
Tokorozawa-shi, Saitama 359-1192
A thin film transistor (TFT) photosensor was applied to leukocyte analysis based on lens-free photodetection. Micro-partitions were directly fabricated on the TFT photosensor surface by photolithography to assemble single cells on a single detection element. Specific detection of individual JM cells, stained with mouse anti-human CD8 IgG1 primary antibody and HRP-labeled anti-mouse IgG1 secondary antibody, as bright-pixels was successfully achieved based on chemiluminescence using the micro-partitioned TFT photosensor integrated into a microfluidic chamber. Furthermore, novel cell analysis system using TFT photosensor and microcavity array was developed for profiling analysis of cell population. This system will allow high-throughput and real-time analysis of more than 104 cells with minimum optical system requirements.
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単離細胞の有する遺伝子検出のためのPCR用マイクロ流路ディスク
創価大院工a、 北陸先端大院大b、産総研健康工学c
○久保いづみa、古谷俊介a、高村 禅b、永井秀典c
CENTRIFUGAL FLOW DISK FOR THE DETECTION OF THE SPECIFIC GENE BY PCR IN THE ISOLATED CELLS
Izumi KUBO a, Shunsuke FURUTANI a, Yuzuru TAKAMURA b and Hidenori NAGAI c
a Department of Bioinformatics, Faculty of engineering, Soka University
Hachioji-shi, Tokyo, 192-8677
b School of Materials Science, JAIST,
1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
c Health Technology Research Center, AIST
1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
A disk-shaped microfluidic device was developed to allow the detection of the specific gene in the isolated cells by PCR. The purpose of this study is continuously to detect a target gene by Polymerase Chain Reaction (PCR) on our centrifugal flow disk. Amplification of a target gene, which was invA of Salmonella, was confirmed on our disk after PCR. We confirmed that fluorescent intensity proportional to amount of target gene, especially from single cell, could be obtained on our centrifugal flow disk after PCR. The distribution of S. enterica depended on a Poisson distribution at various densities of cell suspension. At 200 cells / μl of S. enterica or less, isolated single cells could be determined on our device through the amplified DNA of the invA gene. The chambers containing no, single, two or three cells could be determined on our device. The selective detection of S. enterica was achieved by PCR from a mixture of S. enterica and E. coli on our CD-shaped device.
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マイクロデバイスによる複合微生物のアンモニア代謝能の連続測定
筑波大院数理物質a、筑波大院生命環境b
○戸田憲輔a、八幡 穣b、瀬戸山恵里香b、福田淳二a、野村暢彦b、鈴木博章a
CONTINUOUS MONITORING OF AMMONIA METABOLISM
OF MICROBIAL COMPLEXES IN A MICRODEVICE
Kensuke TODA a, Yutaka YAWATA b, Erika SETOYAMA b,
Junji FUKUDA a, Nobuhiko NOMURA b and Hiroaki SUZUKI a
a Graduate School of Pure and Applied Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305-8573
b Graduate School of Life and Environmental Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305-8572
A microdevice with an integrated NH4+ ion-selective electrode was developed for continuous monitoring of the nitrification activity of microbial complexes for the screening of signal molecules. The device consisted of a glass substrate with thin-film electrodes, a polydimethylsiloxane (PDMS) substrate with chambers for cell culture and an internal electrolyte solution for the NH4+ ion-selective electrode, and a polymethylmethacrylate (PMMA) substrate with an NH4+ ion-selective membrane. On-chip continuous monitoring was realized by using durable thin-film Ag/AgCl electrodes. A small current was continuously applied to the Ag/AgCl electrodes with a pin-hole structure, which significantly improved the stability of the electrodes. The consumption of NH4+ ions by active sludge could be monitored for 48 h. Furthermore, an effective signal molecule for stimulation of the nitrification activity was identified from three acylhomoserine lactone molecules.
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EC tag法による半導体表面へのセンサ分子固定化とそのアフィニティセンサへの応用
九工大院生命体
○若林 諒、松山省太郎、池野慎也、春山哲也
ELECTROCHEMICAL IMMOBILIZATION OF SENSOR MOLECULES ON SEMI-CONDUCTIVE ELECTRODE FOR AFFINITY ASSAY
Ryo Wakabayashi, Sho-taro Matsuyama, Shinya Ikeno, and Tetsuya Haruyama
Dept. of Biological Functions and Engineering, Kyushu Institute of Technology Kitakyushu Science and Research Park, Kitakyushu, Fukuoka 808-0196, Japan
In the cases of molecular electronics devices, ordered molecular layer have to be prepared on electrode is required to have efficient functionalities. The authors have developed site-specific electrochemical molecular immobilization method “EC tag method” for a preparation of ordered molecular layer on electric device. In the present study, sensor molecule was designed and synthesized with parts of affinity region, photo-excitation region and EC tag region. Taking advantages of EC tag method, the sensor molecule was immobilized on a semi-conductor (FTO) surface. The sensor molecules immobilized on FTO have been investigated as photo-excited current based affinity sensor. Output current can be obtained when it was irradiated with laser light. The output current was clearly decreased when a ligand molecules were co-exist which was specifically bound to the affinity region of sensor molecule on FTO. The reason of the current decreasing is based on a occurring of steric hindrance by bound ligands which inhibit current transduction from photo-excited region to the FTO. The sensor can perform prompt and high sensitive affinity assay.
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テロメスタチン誘導体6OTDとヒトテロメア配列の力学的相互作用解析
東京農工大・工a、産総研・バイオメディカル研究部門b
○雨宮陽介a、河野景子a、古永由衣a、飯田圭介a、寺 正行a、
長澤和夫a、池袋一典a、中村 史a,b
FORCE ANALYSIS OF INTERACTION BETWEEN TELOMESTATIN DERIVATIVE 6OTD AND HUMAN TELOMERIC SEQUENCES
Yosuke AMEMIYA a, Keiko KAWANO a, Yui FURUNAGA a, Keisuke IIDA a, Masayuki TERA a,
Kazuo NAGASAWA a, Kazunori IKEBUKURO a and Chikashi Nakamura a,b
a Department of Biotechnology and Life Science,
Tokyo University of Agriculture and Technology,
Koganei-shi, Tokyo 184-8588
b BioMedical Research Institute ,
National Institute of Advanced Industrial Science and Technology (AIST),
Ibaraki 305-8562
The synthetic hexaoxazole telomestatin derivative (6OTD), which is a macrocyclic hexaoxazole, is known to be bound specifically to G-quadruplexes in human telomeric DNA through π-π stacking interactions to form 2:1 complex. We immobilized the 6OTD monomer on a silicon cantilever covalently and oligonucleotides consisting of a human telomeric repeat sequence, (TTAGGG)n (n = 4 or 16) on a gold substrate via streptavidin-biotin interaction. The unbinding force of the 6OTD-DNA complex was examined by using an atomic force microscope (AFM). Alternatively, we used the 6OTD dimmer, which has a linker with an appropriate length to bind to telomeric G-quadruplexes and form 1:1 complex, and evaluated the unbinding force of the 6OTD dimer-DNA complex. As expected, the unbinding force of the 6OTD dimmer-DNA complex was higher than that of the 6OTD monomer-DNA complex. The unbinding mode of the 6OTD-telomeric DNA complexes was discussed here.
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単一細胞内遺伝子発現デジタル解析に向けた１分子cDNAの検出
早大院理工a、日立中研b、東京農工大院工c
○岡村好子a、神原秀記b、松永 是c、竹山春子a,c
DETECTION OF SINGLE cDNA MOLECULES TOWARD DIGITAL COUNTING ANALYSIS OF GENE EXPRESSION WITHIN A SINGLE CELL.
Yoshiko OKAMURA a, Hideki KAMBARA b, Tadashi MATSUNAGA c
and
Haruko TAKEYAMA a,c
a Dept. Life Science and Medical Bio-Science, Waseda University,
Shinjuku-ku, Tokyo 162-840
b Central Research Laboratory, Hitachi, Ltd
Kokubunji-shi, Tokyo 185-8601
c Dept. Biotechnology, Tokyo University of Agriculture and Technology,
Koganei-shi, Tokyo 184-8588
To elucidate dynamics of gene expression within a single cell precisely, digital counting of single mRNA based on pyrosequencing has been developed as a new analytical method. Single template PCR method is key technology for comprehensive gene expression by digital counting analysis. We developed newly single template amplification method by easy-handling. PCR was performed in capillary plate (CP) with well diameter; 25 µm and height; 1000 µm, respectively. A single cDNA was introduced into a pore by DNA dilution. Result of PCR showed that the amplification efficiency per well was equal to PCR efficiency in 100 µL of reaction mixture under the same conditions. In order to collect amplicon from each pore, a 22 µm in diameter of zirconia bead was used. The well height is 40 times more than bead diameter so that hydrogel was utilized to control a single bead on a single well. The amplification efficiency using hydrogel was 1/10 efficiency of normal PCR, however it made possible to apply beads onto CP after PCR reaction. By using biotinylated primer and avidin modified beads, biotinylated amplicon were recovered with 100% efficiency on a bead by avidin-biotin reaction. This single template amplification method provides that enough templates for pyrosequencing can be concentrated on a bead.
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コバルトナノ金属触媒の合成とリン酸イオンセンサへの応用
九工大院工
○辻 慶太朗、高瀬 聡子、清水 陽一
SYNTHESIS OF NANO-COBALT METAL DOPED CARBON AND APPLICATION TO A POTENTIOMETRIC HYDROGEN-PHOSPHATE ION SENSOR
Keitaro TSUJI, Satoko TAKASE, and Youichi SHIMIZU*
Department of Applied Chemistry, Graduate School of Engineering,Kyushu Institute of Technology, Kitakyushu-shi, Fukuoka 804-8550
Determination and control of (hydrogen) phosphate-ions concentration has been becoming very important for reducing the accelerated eutrophicaion of close water system. The aim of this study is to develop an electrochemical sensor for phosphate-ion using Co-nano catalyst based electrode. Co-nano metal doped carbon powder was tried to be prepared by carbon-combustion method using large surface area carbon loaded with Co-nitrate. The Co-doped carbon powders were characterized by means of XRD, TEM and EDX, etc. The Co-carbon thick-film sensor for phosphate-ion was prepared by screen printing method. The thick-film sensor showed relatively good response of potentiometric sensing to phosphate ion in the concentration range between 3.0×10-4M and 1.0×10-2M at pH=5. The 90% response time of the sensor device was as short as about 3 min at room temperature.
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Li+イオン伝導性ガラスセラミックスと炭酸塩を組み合わせた
センサの溶存CO2に対する応答
琉球大理a、琉球大院理工b
○又吉直子a、宮田健史b
DISSOLVED CO2 SENSING PROPERTIES OF ELECTROCHEMICAL SENSOR USING COMBINATION OF LI＋ ION CONDUCTIVE GLASS CERAMICS
AND METAL CARBONATE
Naoko MATAYOSHI a and Takeshi MIYATA b
a Faculty of Science, University of the Ryukyus,
1 Senbaru, Nishihara-cho, Okinawa 903-0213
b Graduate School of Engineering and Science, University of the Ryukyus,
1 Senbaru, Nishihara-cho, Okinawa 903-0213
Electrochemical sensor was obtained by combining a Li3Zr2Si2PO12 glass -ceramics (Li＋ conductor) with an auxiliary phase of a metal carbonate. Li3Zr2Si2PO12 powder was synthesized by a sol-gel method and was pressed into a disc. Two types of sensor element using a Li3Zr2Si2PO12 disc were fabricated. Sensor A : Reference electrode on the disc was covered completely with a coating material to prevent it from coming into contact with sample solutions during sensing experiments. Sensor B : Reference electrode on the disc was not coated and it could contact with sample solutions. The EMF response of Sensor A was linearity holds in pH 7.1 – 6.1 in a phosphate buffer solution at 30℃, following Nernst’s equation. But Sensor B had no EMF response to pH. The EMF response of Sensor A varied logarithmically with a change in dissolved CO2 concentration in the range of 87 to 1300 ppm, with slopes of 31 mV/decade (n = 2) or 15 mV/decade (n = 4) , in a phosphate buffer solution of pH 7.0 at 30℃. The same experimental result was shown by using sensor B.
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カリウムインサーション材料を利用した
全固体型イオン選択性電極の構造と安定性
東京理科大理
○鈴木千裕, 藪内直明, 駒場慎一
STRUCTURE AND POTENTIAL STABILITY OF ALL-SOLID-STATE
ION-SELECTIVE ELECTRODE USING
POTASSIUM ION INSERTION MATERIALS
Chihiro SUZUKI, Naoaki YABUUCHI, Shinichi KOMABA
Department of Applied Chemistry, Tokyo University of Science,
1-3 Kagurazaka, Shinjuku, Tokyo 162-8601
Potassium containing manganese oxides (hollandite-type and birnessite-type structure) were prepared and applied to K+ ion-selective electrode on the basis of redox potential variation of the manganese oxides. To achieve the higher selectivity of potassium ion, the prepared electrodes were covered with plasticized poly(vinyl chloride) membrane containing potassium ionophores. Thus prepared potassium-ion selective electrodes exhibited an ideal Nernstian response in the range of 4×10-5 – 1×10-1 mol dm-3 with high selectivity for potassium ion and good potential stability. AC impedance analysis of the all-solid-state electrodes revealed that the insertion materials were capable of reducing the electrode impedance at the interface and improved the potential stability.
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炭素・有機粘土複合体のパーコレーションを利用した有機塩素化合物用ガスセンサ
金沢工業大学 バイオ・化学部
○露本伊佐男、 飯田勇輝、 堀 晴菜
GAS SENSOR FOR ORGANOCHLORINE COMPOUNDS USING PERCOLATION OF CARBON – ORGANIC CLAY COMPOSITES
Isao TSUYUMOTO, Yuuki IIDA, and Haruna HORI
College of Bioscience and Chemistry, Kanazawa Institute of Technology,Nonoichi, Ishikawa 921-8501
We newly developed a chemical sensor by using a composite comprising of a conducting phase and an insulating phase whose volume increases by the incorporation of an objective substance. The resistivity of the composite changed with the concentration of the objective substance, because the resistivity is closely dependent on the volume fraction of the insulating phase based on the percolation theory. A composite of ordinary montmorillonite with carbon showed a remarkable resistivity increase in humid atmosphere, and furthermore a composite of organic montmorillonite with carbon showed a resistivity increase in atmospheres with organochlorine compounds such as chloroform, dichlorimethane, trichloroethylene, tetrachloroetylene, tetrachloromethane. The resistivities changed reversibly in response to the concentration changes. This is the first gas sensor materials which show resistivity changes in response to inflammable organochlorine compounds, while flammable gases can be easily detected by the conventional semiconductor gas sensors. Structural changes of organic montmorillonite due to the incorporation of chloroform were also discussed by the XRD measurements.
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AuおよびPdナノ粒子修飾カーボン電極を用いたびらん性ガスセンサの開発
熊大院自然科学1、科学警察研究所2、理研計器(株)3
○田島翔太1、岸慎太郎2、佐藤啓太2、松浦宏昭3、中野信夫3、瀬戸康雄2、西山勝彦1
DEVELOPMENT OF ELECTROCHEMICAL GAS SENSOR FOR BLISTER AGENT USING CARBON ELECTRODE MODIFIED WITH GOLD AND PALLADIUM NANOPARTICLES
Shota TAJIMA 1, Shintaro KISHI 2, Keita SATO 2, Hiroaki MATSUURA 3, Nobuo NAKANO 3, Yasuo SETO 2, and Katsuhiko NISHIYAMA 1
1 Graduate School of Science and Technology, Kumamoto University,
2-39-1, Kurokami, Kumamoto 860-8555
2 National Research Institute of Police Science,
6-3-1, Kashiwanoha, Kashiwa 277-0882
3 Riken Keiki Co., Ltd., 2-7-6, Azukizawa, Itabashi-ku 174-8744
Recently, we reported that a compact type of electrochemical sensor1-4) to detect blister agents such as mustard gas (HD) using the carbon electrode modified with gold nanoparticles. In the present study, we will report on the development of HD sensor by using carbon electrode modified with palladium nanoparticles. The sensitivity of the sensor depended on the kind of carbon materials and the amount of modified palladium. On the carbon paper electrode (ca. 5.7 cm2) modified with 7.6 µg cm-2 of palladium nanoparticles at 0.4 V vs. gold black in 9 M H2SO4, ca 3 µA of oxidation current was observed for 24 mg m-3 of HD gas with the flow rate of 300 ml min-1 .The response current decreased with the decrease in the amount of modified palladium. We found that 0.4 µg cm-2 of palladium nanoparticles was required for the detection of 60 mg m-3 of HD gas. The linear relationship of the current vs. [HD] was obtained with the range between 10 and 60 mg m-3 of HD.
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半導体ガスセンサにおける粒子径効果と利用効率の相関
九大院総理工
○島ノ江憲剛、藤山修平、湯浅雅賀、木田徹也
RELATIONSHIP BETWEEN GRAIN SIZE EFFECT AND UTILITY FACTOR FOR SEMMICONDUCTOR GAS SENSORS
Kengo SHIMANOE a, Shuhei Fujiyama b, Masayoshi YUASA a, Tetsuya KIDA a
a Department of Energy and Material Sciences, Faculty of Engineering Sciences,
Kyushu University, Kasuga, Fukuoka 816-8580, Japan
b Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
To develop high-performance semiconductor gas sensors, it is recognized that three key factors, receptor function, transducer function (grain size effect) and utility factor, are important. The importance of the last factor is made obvious when one considers that the target gas (reducing gas) reacts with the oxide surface on its way of diffusion into the sensor device. To detect gas molecules of large size, therefore, introduce of porous structure into the sensing film is required. When large grain size is used, the sensitivity to gas molecule of large size increases. However such sensing film gives low sensitivity against gas molecule of small size like H2. These sensing properties lead to a misunderstanding about relationship between grain size effect and utility factor. In this presentation, we explained proper understanding about them through experiments by using SnO2 with different crystallite sizes. The obtained results pointed out that high sensor response would be realized by optimizing higher order structure parameters such as grain size and pore radius.
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コアーシェルナノ構造半導体センシング材料による高性能ガスセンサの開発
新コスモス電機a、神戸大学b、山梨大学c
○神田奎千a、伊藤達也a、上田 剛a、水畑 穣b、出来成人c
DEVELOPMENT OF A HIGH PERFORMANCE GAS SENSOR USING CORE-SHELL NANOSTRUCTURED GAS SENSING MATERIAL
Keisen Kanda a, Tatsuya Ito a, Tsuyoshi Ueda a, Minoru Mizuhata b, Shigehito Deki c
a New Cosmos Electric Co., Ltd.,
2-5-4 Mitsuyanaka, Yodogawa-ku, Osaka 532-0036
b Department of Chemical Science and Engineering,
Graduate School of Engineering, Kobe University,
1–1, Rokkodaicho, Nada, Kobe 657–8501
c Fuel Cell Nanomaterials Center, University of Yamanashi,
6-43 Miyamae-cho, Kofu 400-0021
A core-shell nanostructured novel semiconductor gas sensing material has been proposed by the authors, and a high performance gas sensor based on the TiO2-SnO2 core-shell nanostructured material has also been developed for the detection of combustible gases such as methane, ethane and propane. The TiO2-SnO2 core-shell nanostructured material was prepared by liquid phase deposition process (LPD), depositing SnO2 nano-layer on the surface of TiO2 particles with mean particle size of 36nm. And the sensor was fabricated by forming a thick film of TiO2-SnO2 core-shell nanostructured material on an alumina substrate with interdigitated electrodes. The thick film is structured by 3 dimensional ultra thin SnO2 film, which showed extremly high sensitivity and fast response to the target gases at its operating temperature with excellent long-term stability. In addition, the humidity dependency of the sensor has much been improved as compared to conventional SnO2 thick film sensor.
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Pt, Pd, Au添加SnO2によるT–VOCセンサのエージング効果
産総研a、富山県工業技術センターb
○伊藤敏雄a、松原一郎a、角崎雅博b、坂井雄一b、
申ウソクa、伊豆典哉a、西堀麻衣子a
AGING EFFECTS ON Pt, Pd, AND Au LOADED SnO2 AS T–VOC SENSORS
Toshio ITOH a, Ichiro MATSUBARA a, Masahiro KADOSAKI b, Yuichi SAKAI b,
Woosuck SHIN a, Noriya IZU a, and Maiko NISHIBORI a
a National Institute of Advanced Industrial Science and Technology (AIST),
Shimo-shidami, Moriyama-ku, Nagoya 463-8560
b Toyama Industrial Technology Center
383 Takada, Toyama 930-0866
This study is an investigation of aging effects on the total volatile organic compound (T-VOC) test gas sensing properties of Pt-loaded SnO2 (Pt/SnO2) and Pt, Pd, and Au-loaded SnO2 (Pt,Pd,Au/SnO2) as gas sensors. The sensor responses of a high humidity aging-Pt,Pd,Au/SnO2, a room air aging-Pt,Pd,Au/SnO2, a non aging-Pt,Pd,Au/SnO2, and a high humidity aging-Pt/SnO2 to test gas have been measured. The high-humidity aging is an effective for resistance to humidity change for the Pt,Pd,Au/SnO2 but not effective for the Pt/SnO2.
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超音波噴霧熱分解による多孔質酸化物粒子の調製と半導体ガスセンサへの応用
長崎大院生産科学a，長崎大工b，Tarbiat Modares University c，4University of Tehran d
○兵頭健生a，Azam Anaraki Firooz b,c，Ali Reza Mahjoubc，Abbas Ali Khodadadid， 清水康博b
PREPARATION OF MACROPOROUS OXIDE POWDERS
PREPARED BY ULTRASONIC SPRAY-PYROLYSIS
AND THEIR APPLICATIONS TO SEMICONDUCTOR GAS SENSORS
Takeo HYODO a, Azam ANARAKI FIROOZ b,c, Ali Reza MAHJOUB c, Abbas Ali KHODADADI d and Yasuhiro SHIMIZU b
a Graduate School of Science and Technology and
b Faculty of Engineering, Nagasaki University,
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
c Department of Chemistry, Tarbiat Modares University, 14115-175, Tehran, Iran
a School of Chemical Engineering, University of Tehran, 11155-4563 Tehran, Iran
Macroporous SnO2 powders doped with and without 1~10 wt% MoO3 (mp-mMoO3-SnO2(n); m: the amount of MoO3 addition (wt%), n: the amount of PMMA microspheres in the precursor solution (g)) have been prepared by ultrasonic spray-pyrolysis employing an aqueous precursor solution containing SnCl4•5H2O, (NH4)6Mo7O24 and polymethylmethacrylate (PMMA) microspheres (ca. 150 nm in diameter). Well-developed macropores (less than 100 nm in diameter) were formed in the mp-mMoO3-SnO2(n) powders and the morphology was dependent on the amount of PMMA microspheres in the aqueous precursor solution. In addition, an increase in m of mp-mMoO3-SnO2(3) was effective in an increase in the specific surface area. Gas-sensing properties to 5 ppm NO2 in air of mp-mMoO3-SnO2(n) films (about 50 μm thick), which were fabricated by screen-printing, were largely dependent on their specific surface area.
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水素雰囲気中で作動可能なダイオード式COセンサの開発
－電極の構造・組成制御による応答特性の改善－
長崎大院生産科学a，長崎大工b
○兵頭健生a，米村允志b，清水康博b
DEVELOPMENT OF DIODE-TYPE CO SENSORS OPERATING
UNDER H2 ATMOSPHERE
-IMPROVEMENT OF THE SENSING PROPERTIES BY STRUCTURAL
AND COMPOSITIONAL CONTROLS OF THE ELECTRODES-
Takeo HYODO a, Masashi YONEMURA b and Yasuhiro SHIMIZU b
a Graduate School of Science and Technology, Nagasaki University,
b Faculty of Engineering, Nagasaki University,
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
CO sensing properties of diode-type gas sensors using an anodized TiO2 film and noble metal electrodes (M/N/TiO2, M (upperlayer) and N (under layer): Pt, Pd-Pt (Pd:Pt = 36:64 (wt%)) or Au) under H2 atmosphere have been investigated in this study. A Pd-Pt/TiO2 sensor pretreated in H2 at 200℃ for 1 h showed relatively high response to 80 ppm CO in H2. The introduction of Au layer between the Pd-Pt electrode and the TiO2 film to the Pd-Pt/TiO2 sensor reduced the CO response, while the coating of Au layer on the Pd-Pt electrode was effective in improving the CO response. On the other hand, the pretreatment in dry air at 600℃ for 1 h enhanced the response and recovery speeds, but reduced the CO response.
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Pt-Ti-OゲートSi-MISFET型水素センサの提案
日立基礎研
○宇佐川利幸、菊池洋太
A Novel Pt-Ti-O gate Si-MISFETs Hydrogen Gas Sensor
Toshiyuki USAGAWA , Yota KIKUCHI
Advanced Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395
A hydrogen gas sensor based on novel platinum-titanium-oxygen (Pt-Ti-O) gate silicon-metal-insulator- semiconductor field-effect transistors (Si-MISFETs) was developed. The sensor has a unique gate structure composed of titanium and oxygen accumulated around platinum grains on top of a novel mixed layer of nanocrystalline TiOx and super heavily oxygen-doped amorphous titanium formed on SiO2/Si substrates. The FET hydrogen sensor shows high reliability and high sensing amplitude (ΔVg), which is well fitted by a linear function of the logarithm of air-diluted hydrogen concentration C(ppm), i.e., ΔVg(V)=0.355Log C(ppm)–0.610, between 100 ppm and 1%. This high ΔVg demonstrates that the sensor is suitable for most hydrogen-safety-monitoring sensor systems. The novel structures of the sensor are typically realized by annealing Pt (15nm)/Ti (5nm)-gate Si-MOS structures in air at 400℃ for two hours. The Pt-Ti-O gate MIS structures were analyzed by transmission electron microscope (TEM), X-ray diffraction, Auger electron spectroscopy, and TEM energy dispersive X-ray spectroscopy (TEM-EDX). From the viewpoint of practical sensing applications, hydrogen post-annealing of the Pt-Ti-O gate Si-MISFETs is necessary to reduce the residual sensing amplitude with long tailing profile.
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Au担持TiO2ナノチューブセンサのVOCガスに対する応答特性
九大院総理工a、鹿児島大学院医歯学総合b
○徐 敏鉉a、湯浅雅賀a、木田徹也a、
上村裕一b、山添 曻a、島ノ江憲剛a
SENSING CHARACTERISTICS TO VOCs GAS
FOR Au-LOADED TiO2 NANOTUBE SENSORS
Min-Hyun SEO a, Masayoshi YUASA b, Tetsuya KIDA b,
Yuich KANMURA c,
Noboru YAMAZOE b, Kengo SHIMANOE b
a Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
b Department of Energy and Material Sciences, Faculty of Engineering Sciences,
Kyushu University, Kasuga, Fukuoka 816-8580, Japan
c Department of Anesthesiology and Critical Care Medicine, Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima
890-8520, Japan
In this study, resistive-type gas sensors using porous flims made of Au-loaded TiO2 nanotubes were developed for the detection of VOCs. The loading of noble metals was carried out to enhance the gas sensing characteristics of TiO2 nanotube-based sensors. Using a photochemical deposition method, Au nanoparticles were successfully deposited on TiO2 nanotubes prepared by a hydrothermal method in a highly-dispersed state. The sensor device using a porous film composed of the Au-loaded TiO2 nanotubes exhibited improved sensor responses to 50 ppm toluene in air at 500℃. We also demonstrated that the device could be used for the detection of 2,6-diisopropylphenol (propofol), an intravenously administered hypnotic drug for induction and maintenance of anesthesia. The Au-loaded TIO2 nanotubes would offer a way to continuously monitor a change in the concentration of VOCs in exhaled air for medical diagnostics. The results demonstrate that the Au loading is a very efficient method for improving the sensing characteristics of TiO2 nanotube-based sensors operative at high temperatures.
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半導体式アルコールチェッカーの高精度化
エフアイエス株式会社
○柳谷順子、 片山 仁、 翁長一夫
HIGH ACCURACY ALCOHOL CHECKER USING A SEMICONDUCTOR GAS SENSOR
Junko YANAGITANI, Hitoshi KATAYAMA and Kazuo ONAGA
FIS Inc. 3-36-3, Kitazono, Itami, Hyogo 664-0891
We investigated to improve alcohol checkers which have a good reproducibility, long life, and easy handling. We have used a bead type small semiconductor gas sensor and optimized the driving condition for the sensor. As a result, we have been able to realize and commercialize the highly sensitive alcohol checker which can operate for long time with a dry battery, with short warm-up time, and excellent reproducibility for the measurement results.
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セラミックスのメソ・マクロ構造設計手法の確立とガスセンサ材料への最適化
長崎大院生産科学
兵頭健生
OPTIMAL DESIGN OF MESO- AND MACRO-STRUCTURES FOR CERAMIC GAS SENSORS
Takeo HYODO
Graduate School of Science and Technology, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
Design approaches of meso- and macro-structures for ceramic gas sensors have been reviewed in this article. Thermally stable mesoporous oxides with large specific surface area and small crystallite size were prepared by utilizing a self-assembly of surfactant in aqueous solution. Macroporous oxide powders and films were fabricated by various wet and dry processes employing a polymethylmethacrylate (PMMA) microsphere as a template. The modification of surface and grain-boundary of oxides with some additives and the structural and compositional controls of boundaries between anodized oxide films and noble metal electrodes were attempted by chemical and physical deposition process, respectively. Meso- and macro-structures of various materials obtained were strictly controlled and optimized to enhance the gas-sensing properties.
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酸化セリウムを用いた抵抗型センサ素子の応答特性と応答機構
産総研a、新コスモス電機b
○松原一郎a、伊藤敏雄a、田口裕子a、伊豆典哉a、中村俊一b、
鈴木健吾b、神田奎千b、
申ウソクa、西堀麻衣子a
SENSING PROPERTIES AND MECHANISM OF CERIUM OXIDE BASED RESISTIVE TYPE SENSOR ELEMENTS
Ichiro MATSUBARA a, Toshio ITOH a, Yuko TAGUCHI a, Noriya IZU a,
Shunichi NAKAMURA b, Kengo SUZUKI b, Keisei KANDA b,
Woosuck SHIN a, and Maiko NISHIBORI a
a National Institute of Advanced Industrial Science and Technology (AIST),
Shimo-shidami, Moriyama-ku, Nagoya 463-8560
b New Cosmos Electric Co., Ltd.
Mitsuya, Yodogawa-ku, Osaka 532-0036
We have investigated gas sensing properties and mechanism of cerium oxide based resistive type sensor elements by using AC impedance technique. The cerium oxide thick film element exhibits the response with a high sensitivity to H2S. The impedance analysis can divide the DC resistance of the elements to the three types of contributions, bulk resistance, grain boundary resistance, and electrode interface resistance. In the case of the cerium oxide thick film element, the response values calculated by the bulk resistance component in the AC measurement are consistent with those in the DC measurement, indicating that the cerium oxide shows the responses by changing the bulk resistivity.
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半導体式ガスセンサに用いられる
SnO2系センシング材料中のドーパントの役割 (1)
―性能と信頼性に及ぼす影響と大型先端機器による解析の試み
新コスモス電機a・産総研b
○前川 亨a、皆越知世a、神田奎千a、野村勝裕b、蔭山博之b
THE ROLE OF DOPANTS IN SnO2-BASED SEMICONDUCTOR GAS SENSING MATERIALS(1) –EFFECTS OF DOPANTS ON SENSING PERFORMANCES AND RELIABILITY OF SENSORS
Toru MAEKAWA a, Chise MINAGOSHI a, Keisen KANDA a, Katsuhiro NOMURA b and Hiroyuki KAGEYAMA b
a New Cosmos Electric Co., Ltd.,
2-5-4 Yodogawa-ku, Osaka city, Osaka 532-0036
b National Institute of Advanced Industrial Science and Technology (AIST),
1-8-31 Midorigaoka, Ikeda city, Osaka 563-8577
Dopants in metal oxide semiconductor sensing materials play important roles in gas sensing performances and reliability of the sensors based on these materials. The authors have prepared a Ce-Sb-SnO2 system with various dopant concentrations by a coprecipitation method, and made crystal structure analyses of the materials using advanced instruments. The authors have also investigated the effects of dopants on gas sensing performances and reliability of the sensors based on the materials.
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半導体式ガスセンサに用いられる
SnO2系センシング材料中のドーパントの役割(2)
－Photon Factoryを利用したＸＡＦＳによる微量分析
新コスモス電機株式会社a、産総研b、高エネ研c
皆越知世a、前川 亨a、神田奎千a、野村勝裕b、○蔭山博之b、
新田清文c、西野潤一c、仁谷浩明c、野村昌治c
THE ROLE OF DOPANTS IN SnO2-BASED SEMICONDUCTOR GAS SENSING MATERIALS (2)— FLUORESCENCE XAFS ANALYSIS USING PHOTON FACTORY
Chise MINAGOSHI a, Toru MAEKAWA a, Keisen KANDA a, Katuhiro NOMURA b, Hiroyuki KAGEYAMA b, Kiyofumi NITTA c, Junichi NISHINO c, Hiroaki NITANI c and Masaharu NOMURA c
a New Cosmos Electric Co., Ltd,
2-5-4, Yodogawa-ku, Osaka city, Osaka 532-0036
b National Institute of Advanced Industrial Science and Technology,
1-8-31 Midorigaoka, Ikeda city, Osaka 563-8577
c Institute of Materials Structure Science,
High Energy Accelerator Research Organization,
1-1 Oho, Tsukuba city, Ibaraki 305-0801
We have recently studied SnO2-based sensing materials used for semiconductor type gas sensors to control sensitivity and selectivity to a target gas and to improve reliability over a long period of time at high operating temperatures. In this work we measured Ce L3- and Sb K-edge XAFS of the Ce-Sb-SnO2 system with low concentration Ce and Sb doping, (a mol%)Ce-(b mol%)Sb-SnO2 (0≦a≦3.0, 0≦b≦3.0) in the fluorescence mode using a 19-element germanium array detector at beamlines in the Photon Factory and PF-AR. The results of the XAFS analysis showed that the valence state of Sb ions varies between 3+ and 5+ depending on doping concentration of Sb ions and with coexistence of Ce ions. Also the height and position of three peaks in the Ce L3-XANES region changed depending on the Ce doping concentration, while relatively small change of the profile of XANES region was found with coexistence of Sb ions.
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半導体式ガスセンサに用いられる
SnO2系センシング材料中のドーパントの役割 (3)
－Ｘ線回折法・中性子回折法による結晶構造解析
産総研a、新コスモス電機b
○野村勝裕a、蔭山博之a、皆越知世b、前川 亨b、神田奎千b
THE ROLE OF DOPANTS IN SnO2-BASED SEMICONDUCTOR GAS SENSING MATERIALS (3) – CRYSTAL STRUCTURE ANALYSES USING X-RAY AND NEUTRON DIFFRACTION METHODS
Katsuhiro NOMURA a , Hiroyuki KAGEYAMA a,
Chise MINAGOSHI b,
Toru MAEKAWA b and Keisen KANDA b
a National Institute of Advanced Industrial Science and Technology (AIST),
1-8-31 Midorigaoka, Ikeda city, Osaka 563-8577
b New Cosmos Electric Co., Ltd.,
2-5-4 Yodogawa-ku, Osaka city, Osaka 532-0036
Lattice constants and crystal structure parameters of SnO2-based sensing materials, (a mol%)Ce-(b mol%)Sb-SnO2 (0 ≤ a ≤ 3.0, 0 ≤ b ≤ 3.0), have been refined by the Rietveld analysis of powder X-ray diffraction (XRD) data containing an internal standard of Si (NIST, SRM640c) and neutron diffraction (ND) data. The lattice constants (a- and c-axes) increased linearly up to 0.8mol% Ce- or 1.0mol% Sb-doping. The electron and nuclear density distributions of the sensing materials have been studied by a Rietveld refinement, a maximum entropy method (MEM), and MEM-based pattern fitting of XRD and ND data.
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Pt/WO3薄膜のガスクロミック特性に及ぼす湿度影響
横浜国立大学a、東京大学b
○山崎亮介a、岡崎慎司a、横山 隆a、伊藤大輔a、小柴佑介a、中川英元b
AN INFLUENCE OF HUMIDITY ON GASOCHROMIC BEHAVIOR
OF Pt/WO3 THIN FILMS
Ryousuke Yamasaki, Shinji Okazaki, Takashi Yokoyama,
Daisuke Ito, Yusuke Koshiba, Hidemoto Nakagawa
a Yokohama National University
79-5 Tokiwadai Hodogayaku Yokohama Japan 240-8501
b University of Tokyo
A clean energy system using hydrogen has been paid much attention. However, hydrogen is hazardous material because of its explosive nature. Therefore, the leakage detection of hydrogen is very important. The coloring reaction of the noble metal supported WO3 thin films with the exposure to hydrogen gas is well-known. This phenomenon is called gasochromism. In this research, gasochromic response of WO3 thin films at wavelength of 1.3 μm as a hydrogen gas sensor was quantitatively evaluated. The optical transmittance measurements were conducted in airtight chamber at room temperature. The humidity of test gas was controlled from 0% to 90%. Pt/WO3 thin films on quartz glass substrate were prepared by sol-gel method. Considerable change in transmitted light intensity was observed even in a concentration range less than 1% of hydrogen. However, the gasochromic reaction was seriously inhibited in the presence of humidity.
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吸入麻酔薬セボフルラン蒸気に対する
触媒化学発光式ガスセンサの検知特性
千科大危a、岡理大理b
○岡林 徹a、 尾崎眞啓b、中川益生b
SENSING CHARACTERISTICS OF CATALUMINESCENCE-BASED GAS-SENSOR FOR SEVOFLURANE VAPOR
Tohru OKABAYASHI a , Masahiro OZAKI b and Masuo NAKAGAWA b
a Faculty of Risk and Crisis Management, Chiba Institute of Science,
Choshi-shi, Chiba 288-0025
b Faculty of Science, Okayama University of Science,
Okayama-shi, Okayama 700-0005
Sensing characteristics of cataluminescence(CTL)-based gas-sensor for sevoflurane vapor is described. Sevoflurane is a typical anesthetic agent, and is used for the patients during their surgical operation. CTL is a kinds of chemiluminescence emitted during the catalytic oxidation of combustible gases. Reproducible CTL is observed during the catalytic oxidation of sevoflurane on γ-Al2O3:Tb at 600℃. The CTL intensity is proportional to the square root of flow velocity of the sevoflurane vapor ranging from 8 to 26.5 cm/s. The CTL intensity is proportional to the sevoflurane concentration ranging from 2 to 50 ppm.
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高感度NO2センサ端末の開発及び広域ユビキタスNWへの適用
NTT環境研a、NTT未来研b
○丸尾容子a、中村雅之a、中村二朗a、東島由佳b、菊谷幸雄b、中村元紀b
DEVELOPMENT OF HIGHLY SENSITIVE NITROGEN DIOXIDE MONITORING
DEVICE AND IT APPLICATION TO WIDE AREA UBIQUITOUS NW
Yasuko Y. MARUO a, Masayuki NAKAMURA a, Jiro NAKAMURA a, Yuka HIGHSHIJIMA b, Yukio KIKUYA b and Motonori NAKAMURA b
a NTT Energy & Environmental Laboratories, Atsugi-shi, Kanagawa 243-0198
b NTT Network Innovation Laboratories, Musashino-shi, Tokyo 180-8585
We have constructed sensing terminal units containing a NO2 sensor, a GPS device, a compass, a switch, LEDs and a wireless terminal unit of the wide area ubiquitous network. The NO2 sensor contained a highly sensitive sensor element that employs a colorimetric reaction between nitrogendioxide and Salzman reagents. We achieved outdoor nitrogendioxide monitoring every ten minutes using the developed terminal units in some area of Katsushika, Tokyo. We also designed and implemented an application that navigates bicycles using air quality, location, and direction of movements informations gathered by the sensing terminal units.
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液膜二極式COセンサ検知機構の電気化学的解析
大阪ガス株式会社a、フィガロ技研株式会社b
○野中 篤a、中島 崇a、中山敏郎a、大西久男a、
野中英正a、岡田正文b、藤森裕樹b、井上智弘b
ELECTROCHEMICAL ANALYSIS OF SENSING MECHANISM OF A LIQUID ELECTROLYTE MEMBRANE TYPE CO SENSOR
Atsushi NONAKA a , Takashi NAKAJIMA a, Toshiro NAKAYAMA a, Hisao OHNISHI a,
Hidemasa NONAKA a, Masafumi OKADA b, Yuki FUJIMORI b and Tomohiro INOUE b
a Osaka Gas Co., Ltd., Torishima, Konohana-ku, Osaka 554-0051
b Figaro Engineering Inc., Senbanishi, Mino-shi, Osaka 562-8505
In order to clarify the electrochemical behavior at detecting CO, polarization curves of a working electrode and a counter electrode of a liquid electrolyte membrane type CO sensor were measured using Pt wire as a reference electrode. As a result, short-circuit current between both electrodes in the air containing CO is approximately a half of diffusion limited current of a CO oxidation reaction on the working electrode. CO concentration dependency on the sensor’s output current is determined by not a mixed potential voltage but a concentration dependency on diffusion limited current in the CO oxidation reaction on the working electrode.
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液膜二極式COセンサの電解液膜機能の自己診断手法の開発
フィガロ技研株式会社a、大阪ガス株式会社b
○岡田正文a、井上智弘a、藤森裕樹a、野中英正b、野中 篤b、中島 崇b
DEVELOPMENT OF SELF-DIAGNOSIS FOR EFFICIENCY ON
A LIQUID ELECTROLYTE MEMBRANE TYPE CO SENSOR
Masafumi OKADA a ,Tomohiro INOUE a, Yuki FUJIMORI a,
Hidemasa NONAKA b,Atsushi NONAKA b, and Takashi NAKAJIMA b
a Figaro Engineering Inc.
Senbanishi,Mino-shi, Osaka 562-8505
b Osaka Gas Co.,Ltd.
Torishima,Konohana-ku, Osaka 554-0051
Regarding the liquid electrolyte membrane type CO sensor, it has a water reservoir which prevents the drying of electrolyte membrane. While a conventional self-diagnosis method can only detect a completely dried-up status of the electrolyte membrane, the promising self-diagnosis principle which can detect an fall of function for electrolyte membrane has been developed by measuring an impedance of the sensor. This report presents the efficiency for the advanced self-diagnosis concept.
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LaGaO3系固体電解質を用いた電流検出型COセンサ
(3)活性電極の金属の複合効果
九大院工
○岩田 純、Phawachalotorn Amornrat、萩原英久、伊田進太郎、石原達己
Amperometric CO Sensor using LaGaO3 based solid electrolyte
(3) Effects of metal addition on the active electrode
Jun Iwata, Phawachalotorn Amornrat, Hidehisa Hagiwara,
Shintaro Ida, Tatsumi Ishihara
Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-Ku, Fukuoka, 819-0395
Amperometric CO sensor in exhaust gas was studied based on the oxygen pumping current. It was fund that the oxygen pumping current sensitively varied with CO concentration when Au and RuO2 were used for inactive and active electrode. It was found that a combination of In0.95Sn0.05O3 with Au and RuO2 with La0.6Sr0.4CoO3 was suitable for the detection of CO. In this study, effects of metal additives on active electrode were studied for increasing CO sensitivity. Among the various metals, addition of Pt was effective for increasing CO sensitivity. Addition of Pt is also effective for improving response characteristics.
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高選択的ＣＯ検知用としての２種類の酸化物(+Au)検知極を用いたジルコニアセンサ
九州大学産学連携センターa, 九州大学炭素資源国際教育研究センターb
○スリ アユ アンガライニa、ブラディミル プラシニツァb、三浦 則雄a
ZIRCONIA-BASED SENSOR COMBINED WITH TWO OXIDE(+AU) SENSING ELECTRODES FOR HIGHLY SELECTIVE CO DETECTION
Sri Ayu ANGGRAINI a, Vladimir V. PLASHNITSA b, Norio MIURA a
a Art, Science and Technology Center for Cooperative Research,
Kyushu University
Kasuga-shi, Fukuoka 816-8580
b Research and Education Center of Carbon Resources, Kyushu University
Kasuga-shi, Fukuoka 816-8580
In order to achieve a highly selective and sensitive response to CO in ppm level, a pair of Nb2O5(+Au) and NiO(+Au)-sensing electrodes (SEs) were fabricated in planar yttria-stabilized zirconia (YSZ)-based sensor. Preliminary tests of each of these SEs that formed separately in YSZ-based sensor with respect to Pt-reference electrode (RE) revealed that Nb2O5(+Au)-SE showed rather high sensitivities to both of CO and hydrocarbons (HCs) at 450℃ under the wet condition. On the contrary, the sensor using NiO(+Au)-SE exhibited high sensitivities to HCs and rather moderate response to CO. Thus, the combination of these two SEs is theoretically expected to be capable of reducing responses to HCs, maintaining high sensitivity and selectivity to CO. The experimental observation of the pair of Nb2O5(+Au)- and NiO(+Au)-SEs in YSZ-based planar sensor (combined-type) at 450℃ confirmed the validity of theoretical expectation: the sensitivity to all gases except for CO were diminished, keeping the CO response high enough. The CO sensitivity of the combined-type sensor varied linearly with the logarithm of CO concentration in the range of 10-400 ppm.
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Mn系固体参照極を用いた小型ジルコニアガスセンサ
九大院総理工a、九大炭素資源国際教育センターb、九大産学連携センターc
○ハン ジンa, 和間良太郎a, ブラディミル プラシニツァb, 三浦則雄c
MINIATURIZED ZIRCONIA-BASED GAS SENSOR ATTACHED WITH Mn-BASED SOLID-STATE REFERENCE-ELECTRODE
Han JIN a, Ryotaro WAMA a, Vladimir V. PLASHNITSA b, Norio MIURA c
a Interdisciplinary Graduate School of Engineering Science, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
b Research and Education Center of Carbon Resources, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
c Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
A miniaturized planar-type yttria-stabilized zirconia (YSZ)-based sensor was fabricated by replacing the conventionally used Pt/air reference-electrode (RE) with a newly-developed Mn2O3-based RE. To evaluate the performance of the Mn2O3-based RE, the sensor was coupled with Pt and Au sensing-electrodes (SEs). As a result, the planar sensor using a pair of Pt-SE and Mn2O3-based RE worked perfectly as an oxygen sensor and a lambda sensor, obeying Nernst equation in the wide oxygen concentration range at 550℃. In addition, the sensor using a couple of Au-SE and Mn2O3-based RE exhibited high sensitivity to various hydrocarbons (HCs) at 550℃. The sensing performances of Pt- and Au-SEs used in a miniaturized rod-type sensor with respect to Mn2O3-based RE were found to be almost same as those obtained for the conventional tubular sensor attached with inner Pt/air-RE. This suggests the validity of use of the solid-state Mn2O3-based RE in a YSZ-based planar gas sensor.
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ディーゼルパティキュレートセンサにおける高感度・高レスポンス電極の設計
名大院環境a、日本自動車部品総合研究所b
○竹内貴志a、沈 岩柏a、日比野高士a、原田敏彦b、寺西真哉b
DESIGN OF A HIGHLY SENSITIVE AND RESPONSIVE ELECTRODE FOR DIESEL PARTICULATE MATTER SENSOR
Takashi TAKEUCHI a, Yanbai SHEN a, Takashi HIBINO a,
Toshihiko HARADA b, and Shinya TERANISHI b
a Graduate School of Environmental Studies, Chikusa-ku, Nagoya University,
Nagoya 464-8601
b Nippon Soken, Inc., Nishio-shi, Aichi-ken, 445-0012
In a sensor device, Pt+carbon|Sn0.9In0.1P2O7|Pt, electrochemical carbon oxidation at the working electrode enabled continuous carbon monitoring while self-regenerating, which was based on the reactivity of active oxygen to carbon and on high current efficiency. However, this reaction could not be developed in the whole electrode layer, causing insufficient sensing properties such as low sensitivity and response speed. The main reason for the limitation of carbon oxidation was the lack of proton conduction in the working electrode. In order to overcome this problem, we have attempted to add a proton-conducting Sn0.9In0.1P2O7 ionomer to the working electrode. The Sn0.9In0.1P2O7 ionomer was successfully distributed in the working electrode at some μm level, providing a number of reaction sites for carbon oxidation in the whole electrode layer. As a consequence, compared to the case of the ionomer-free working electrode, carbon oxidation continued until 1.5 times higher currents, leading to a 1.4times higher sensitivity toward carbon. Moreover, a considerable improvement of the response time was achieved.
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極低濃度の炭化水素検出用としての小型ジルコニアセンサ
九大院総理工a、国立環境研究所b、九大産学連携センターc
○末次祐太a、佐藤伴光a、内山政弘b、三浦則雄c
MINIATURIZED ZIRCONIA-BASED SENSOR FOR DETECTION OF
VERY LOW CONCENTRATION OF HYDROCARBON
○Yuta SUETSUGU a, Tomoaki SATO a, Masahiro UTIYAMA b, Norio MIURA c
a Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
b National Institute for Environmental Studies,
Tsukuba-shi, Ibaraki 305-0053
c Art, Science and Technology Center for Cooperative Research, Kyushu University,
Kasuga-shi, Fukuoka 816-8580
The mixed-potential-type yttria-stabilized zirconia (YSZ)-based tubular sensor attached with In2O3 sensing-electrode (SE) has been recently found to be capable of providing rather good sensitivity and selectivity to low concentration of propylene (C3H6) in several tens ppb level. In this study, the YSZ-based C3H6 sensor was miniaturized and its sensing characteristics were evaluated aiming at adjusting them to a feasible practical application. As a result, the C3H6-sensing characteristics of the miniaturized rod-type YSZ-based sensor operated at 450℃ under the wet condition (+1.35 vol.% H2O) were confirmed to be comparable with those obtained previously for the tubular-type sensor. Moreover, the short-term stability of the present miniaturized sensor was improved by optimization of structure and morphology of SE. In addition, the preliminary measurements of C3H6-sensing characteristics were performed by assembling the miniaturized rod-type sensor on a compact self-heating alumina substrate.
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