• 센서학회지
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• 제21권4호
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• pp.311-317
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• 2012

Disposable amperometric screen-printed biosensor strips have been fabricated by a sol-gel encapsulation for the analysis of glucose. The glucose oxidase(GOx) is entrapped in the gel matrix through sol-gel transition of tetraethoxysliane(TEOS). The biosensor is fabricated by GOx containing thin film of TEOS gel on the surface of screen-printed carbon electrode(SPCE). The GOx-containing thin film of TEOS gel offers a one-step modification process on the surface of SPCE. The optimum conditions for glucose determination have been characterized with respect to the applied potential, enzyme loading ratio, and pH. The linear range and detection limit of glucose detection were from 2.0 mM to 16.0 mM and 0.25 mM, respectively.

• 전기학회논문지
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• 제57권11호
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• pp.2006-2010
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• 2008

In this paper, we fabricated a biosensor for detecting hydrogen peroxide and investigated the sensing property. We prepared a viologen and hemoglobin modified gold electrode using self-assembly and layer by layer method. The electrochemical property of the viologen derivative was characterized in 0.1 M $NaClO_4$ electrolyte solution by cyclic voltammetry. The modified electrode showed reversible electrochemical properties and high stability. From the results, the viologen can act as a charge transfer mediator for access to the electrode surface. The catalytic characteristics of the designed sensor proved that hemoglobin has been kept in its natural structure and can retain its biological activity. The designed biosensor showed a fast amperometric response, excellent linearity and low detection limit. In addition, it had high sensitivity, good reproducibility and stability.

• 미생물학회지
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• 제30권6호
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• pp.553-557
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• 1992

변형된 Pfennig 배지에서 Glutamate 를 질소원으로 배앙한 다음 수확된 Chlorobium limicola f. thiosulfatophilum NCIB 8327 의 세포에서 수소생산이 수소 전극법 (hydrogen electrode)으로 측정되었다. 이 방법에 의해서 수소발생을 측정할 때, 산소, 빛, 암모니아 NADPH, ATP, methionine sulfoximine, NADPH, ATP, methionine sulfoximine, NADPH, ATP, methl viologen, 및 methionine sulfoximine 의 농도에 따라 변하는 것을 보았을 때 본 균주에서의 수소생산은 nitrogenase 에 의존하고 있음을 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1460-1461
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• 2008

마이크로칩 형태에서의 모세관 전기영동과 전류법을 이용하여 디옥시리보핵산(DNA) 단편들의 분리 검출하는 실험을 하였다. 마이크로 채널이 형성된 PDMS(polydimethylsiloxane)와 금 전극이 형성된 유리 기판을 접합하여 마이크로칩을 제작하였다. 20V/cm의 전계를 인가하여 100bp-1.5kbp 길이의 DNA 단편을 모세관 전기영동 하였을 때 250초내에 분리 검출되는 것을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권10호
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• pp.449-452
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• 2005

We fabricated an electrochemical detector (ECD) to catalyze redox reaction efficiently by electrodepositing Prussian blue (PB) on the indium tin oxide (ITO) electrode. Capillary electrophoresis (CE) and amperometric method were used. We investigated the PB surface properties by topography from atomic force microscopy (AFM). Also PB film thickness calibration with respect to deposition time and voltage was used to get better PB surFace. The PB thin film of dense and smooth surface could catalyze redox reaction efficiently. Comparing with CE-ECD microchip using bare-lTO electrode, proposed CE-ECD microchip using PB deposited electrode has shown better sensitivity by determining the detected peak current from the electropherograms while the concentration of tested analyzes was maintained the same. It is verified that detection limit can be lowered for 0.01 mM of dopamine and catechol respectively.

• 센서학회지
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• 제16권6호
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• pp.449-456
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• 2007

The work described in this study concerns the development of a disposable amperometric sensor for the electrochemical detection of a well-known aqueous pollutant, free available chlorine (FAC). The FAC sensor developed used screen printed carbon electrodes (SPCEs) coupled with immobilised syringaldazine, commonly used as an indicator in photometric FAC detection, which was directly immobilised on the surface of SPCEs using a photopolymer PVA-SbQ. To enable in-field analysis of FAC, a prototype hand-held electrochemical analyzer has been developed to withstand the environment with its rugged design and environmentally sealed connections; it operates from two PP3 (9 volt) batteries and is comparable in accuracy and sensitivity to commercial bench top systems. The sensitivity of the FAC sensor developed was $3.5{\;}nA{\mu}M^{-1}cm^{-2}$ and the detection limit for FAC was found to be $2.0{\;}{\mu}M$.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1175-1180
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• 2013

A microfabricated electrochemical cell comprising PDMS-based microchannel and in-channel gold microelectrodes was fabricated as a sensitive and a miniature alternative to the conventional electroanalytical systems. A reproducible fabrication procedure enabled patterning of multiple microelectrodes integrated within a PDMS-based fluidic network. The active area of each electrode was $200{\mu}m{\times}200{\mu}m$ with a gap of $200{\mu}m$ between the electrodes which resulted in a higher signal to noise ratio. Also, the PDMS layer served the purpose of shielding the electrical interferences to the measurements. Analytes such as potassium ferrocyanide; amino acid: cysteine and nucleoside: guanosine were characterized using the fabricated cell. The microchip was comparable to bulk electrochemical systems and its applicability was also demonstrated with flow injection based rapid amperometric detection of DNA samples. The device so developed shall find use as a disposable electrochemical cell for rapid and sensitive analysis of electroactive species in various industrial and research applications.

• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.505-510
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• 2006

A gallocyanine-bound nanoporous titanium dioxide electrode system was investigated to carry out a mediated enzyme reaction. Gallocyanine was bound either directly or through an aminopropylsilane linker to the film of nanoporous titanium dioxide and used as a mediator for nitrate reductase in the mediated enzymatic nitrate reduction. The electrode with the aminopropylsilane linker showed 20% higher efficiency of electron transfer at the same potential than that directly linked. The prepared electrodes showed $0.26{\mu}mol/h$ nitrate reduction at a $100mm^2$ surface of the electrode, and linear current response on nitrate ion concentration up to 1.0 mM, which is very useful as a biosensor of nitrate ion in water.

• 센서학회지
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• 제19권6호
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• pp.421-427
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• 2010

Alizarin Red S modified screen printed carbon electrodes were developed for the electrochemical detection of aluminum ion. The electrodes developed use screen-printed carbon electrodes(SPCEs) coupled with chemical modification with an organic chelator, Alizarin Red S(ARS), for aluminum ion detection in aqueous solution. For sensor fabrication ARS was directly immobilized on the surface of SPCEs using PVA-SbQ(The poly(vinyl alcohol) bearing stryrylpyridinium groups). Aluminum concentrations were indirectly estimated by amperometric determination of the non-complexed ARS immobilized on the electrodes, after its complexation with aluminum. The sensitivity of the sensor developed was $3.8\;nA{\mu}M^{-1}cm^{-2}$ and the detection limit for aluminum was $25\;{\mu}M$.

• Bulletin of the Korean Chemical Society
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• 제18권9호
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• pp.952-957
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• 1997

Modified polymeric composite electrodes having highly dispersed CuO particles through the electrode matrix were prepared for LCEC or flow injection analysis of carbohydrates. The composite electrodes were prepared by incorporating carbon black and highly dispersed copper oxide particles in polystyrene matrix cross-linked with divinylbenzene. The analytical characteristics of the electrodes for LCEC and flow injection analysis of carbohydrates were evaluated. Improved performance in LCEC and flow injection analysis of carbohydrates is demonstrated in terms of sensitivity, reproducibility, stability and surface renewability. It was possible to get improved performance of the electrodes as well as adaptability of the electrodes for practical applications by employing highly dispersed catalyst particles through the electrode matrix and robust polymeric electrode matrix.