• 센서학회지
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• 제25권3호
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• pp.173-177
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• 2016

Tape casting ceramics technology has been adopted for the fabrication of solid state electrochemical $CO_2$ sensors and the packaging substrates. The fabricated $CO_2$ sensors exhibit a fast response and a good recovery with the almost theoretical sensitivity of 37 mV/decade, corresponding to a sensor operating temperature of 373 K. The two packaging methods, the wire bonding package and the surface- mounted on the ceramic package, were compared with respect to their power consumption and mass production feasibility. In terms of the ease of fabrication, the surface mount packaging technology is superior to the wire bonding technology but its power consumption is approximately twice that of the wired package.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.561-564
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• 2000

Silicon capacitive pressure sensor has been fabricated by using electrochemical etching stop and silicon-to-glass electrostatic bonding technique. A diaphragm structure is designed to compensate the nonlinear response. A cavity is etched into the silicon to the depth of 2$\mu\textrm{m}$ by anisotropic etching in 20wt.% TMAH solution at 80$^{\circ}C$. A fabricated sensor showed 3.3 pF zero-pressure capacitance, 297 pp.m/mmHg sensitivity, and a 7.4 7%F.S. nonlinear response in a 0-1 kgf/cm$^2$pressure range.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 1998년도 제1회 총회 및 추계학술발표회
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• pp.27-27
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• 1998

• Korean Chemical Engineering Research
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• 제59권2호
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• pp.159-164
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• 2021

부착형(attachable) 타입의 웨어러블 디바이스 적용을 위한 패브릭(fabric)이나 텍스처(textiles) 타입의 고성능 전극 소재 개발에 대한 필요성이 부각되고 있다. 본 연구에서는 유연 전극 소재로 탄소나노튜브 섬유(CNT fibers)를 응용하고자, CNT fibers의 전기화학적 특성과 이를 적용한 비효소적 글루코스 센싱 성능을 확인하였다. CNT fibers의 표면 구조는 주사전자 현미경(SEM)을 이용하여 분석하였으며, 전기화학적 특성 및 센싱 성능 분석은 시간대전류법와 순환전압 전류법, 전기화학 임피던스 분석법을 이용하여 수행되었다. CNT fibers 전극은 낮은 capacitive current와 산화-환원 화학종과 전극 계면 간의 효율적인 direct electron transfer에 의한 우수한 electrochemical activity 등 향상된 전기화학적 특성으로 인해 높은 감도와 넓은 선형 농도 범위, 그리고 낮은 검출 한계 등 우수한 센싱 특성을 보였다. 따라서, 본 연구는 CNT fibers 기반의 고성능 유연 전극 소재 개발을 위한 기초 연구로 활용될 수 있을 것으로 기대된다.

• Korean Chemical Engineering Research
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• 제56권5호
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• pp.705-710
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• 2018

본 연구에서는 백금 나노입자가 분산된 산화구리 나노구조체 기반의 비효소적 글루코스 센서를 개발하였다. 3차원 구조의 산화구리 나노구조체는 hydrothermal method를 통해 Cu foil 위에 직접 합성되었으며, 합성된 나노구조체 표면위에 전기화학적 증착법으로 백금 나노입자들을 분산시켜 전극을 제작하였다. 준비된 전극 샘플의 표면 구조는 주사 전자 현미경(SEM)과 에너지분산형 분광기(EDS)을 이용하여 분석하였으며, 전기화학적 특성 및 센싱 성능은 알칼리 상태에서 시간대전류법 (CA)과 순환전압 전류법(CV)을 통하여 조사하였다. 개발된 비효소적 글루코스 센서는 산화구리 나노구조체와 백금 나노입자의 접목에 의한 시너지 효과 덕분에 높은 감도와 넓은 선형 구간, 빠른 감응 속도 등의 향상된 센싱 특성을 보였다.

• Korean Chemical Engineering Research
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• 제57권5호
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• pp.606-610
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• 2019

본 연구에서 우리는 보론 도핑된 다이아몬드 나노물질을 이용하여 유연성 탄소 섬유 기반의 전극(CF-BDD 전극)을 개발하고, 이를 비효소적 글루코스 센서에 적용하여 전기화학적 특성을 확인하였다. 이 전극은 탄소 섬유 표면에 정전하 자기조립법을 이용하여 BDD 층을 증착하여 제작하였다. 이 전극 물질의 표면 구조는 주사전자 현미경(SEM)을 이용하여 분석하였으며, 전기화학적 특성 및 센싱 성능 분석은 시간대전류법(CA)와 순환전압 전류법(CV), 전기화학 임피던스(EIS)으로 실행하였다. 제작된 CF-BDD 전극은 산화-환원 화학종과 전극 계면 간의 effective direct electron transfer와 large effective surface area, high catalytic activity의 우수한 특성들을 보였다. 결과적으로, CF 센서와 비교에서 CF-BDD 센서는 더 넓은 선형 농도 범위(3.75~50 mM)와 더 빠른 감응 시간(3초 이내), 더 높은 감도(388.8 nA/mM) 등의 향상된 센싱 특성을 보였다. 따라서, 본 연구에서 개발된 전극 물질은 다양한 전기화학 센서 뿐 아니라, 웨어러블 센서 소재로도 활용 가능할 것으로 기대된다.

• 한국생산제조학회지
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• 제21권4호
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• pp.575-581
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• 2012

The electrochemical oxygen demand (ECOD) is an additional sum parameter, which has not yet found the attention it deserves. It is defined as the oxygen equivalent of the charge consumed during an electrochemical oxidation of the solution. Only one company has yet developed an instrument to determine the ECOD. This instrument uses $PbO_2$-electrodes for the oxidation and has been successfully implemented in an automatic on-line monitor. A general problem of the ECOD determination is the high overpotential of electrochemical oxidations of most organic compounds at conventional electrodes. Here we present a new approach for the ECOD determination, which is based on the use of a solid composite electrodes with highly efficient electro-catalysts for the oxidation of a broad spectrum of different organic compounds. Lead dioxide as an anode material has found commercial application in processes such as the manufacture of sodium per chlorate and chromium regeneration where adsorbed hydroxyl radicals from the electro-oxidation of water are believed to serve as the oxidizing agent. The ECOD sensors based on the Au/$PbO_2$ electrode were operated at an optimized applied potential, +1.6 V vs. Ag/AgCl/sat. KCl, in 0.01 M $Na_2SO_4$ solution, and reduced the effect of interference ($Cl^-$ and $Fe^{2-}$) and an expended lifetime (more than 6 months). The ECOD sensors were installed in on-line auto-analyzers, and used to analyze real samples.

• Journal of Electrochemical Science and Technology
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• 제11권3호
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• pp.310-317
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• 2020

A development of disposable strip-type galactose sensor for point-of-care testing (POCT) was studied, which was constructed using screen-printed carbon electrodes. Galactose levels were determined by the redox reaction of galactose oxidase in the presence of potassium ferricyanide as an electron transfer mediator in a small sample volume (i.e., less than 1 µL). The optimal performance of biosensor was systematically designated by varying applied potential, operating pH, mediator concentration, and amount of enzyme on the electrode. The sensor system was identified as a highly active for the galactose measurement in terms of the sensitivity (slope = 4.76 ± 0.05 nA/µM) with high sensor-to-sensor reproducibility, the linearity (R² = 0.9915 in galactose concentration range from 0 to 400 µM), and response time (t_95% = <17 s). A lower applied potential (i.e., 0.25 V vs. Ag/AgCl) allowed to minimize interference from readily oxidizable metabolites such as ascorbic acid, acetaminophen, uric acid, and acetoacetic acid. The proposed galactose sensor represents a promising system with advantage for use in POCT.

• 한국소음진동공학회논문집
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• 제24권12호
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• pp.977-984
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• 2014

Nanomaterial have grown from scientific interest to commercial products and the nanomaterial market has grown 19.1 % each year. As the nanomaterial market size increases, it is expected that nanomaterial production will increase and its contamination of outdoor environmental system will also increase in the form of industrial waste. Since most of nanomaterials are known as biologically non-degradable materials, nanomaterials will accumulate in the environment, and this will increase the potential threats to human health along the food chain. Recent studies have investigated the toxicity effect of nanomaterials due to their size, chemical composition and shape. For the development of nanomaterial while taking human health into consideration, a nanomaterial detecting sensor is required. In this paper, we have observed the trend of nanomaterial detecting sensor of mechanical, electrochemical, optical and kelvin probe force microscopy sensors and we believe that this trend will shed the light on the development of real-life nanomaterial detecting sensors.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2574-2576
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• 2009

In this work, we describe a new sensor that specifically responds to biothiols, i.e., glutathione (GSH), in solution. An electrochemical transducing strategy was utilized and cyclic voltammetry (CV) was employed to monitor the presence of GSH in real time. Our approach harnessed self-assembled monolayers (SAMs) on gold consisting of an alkanethiolate which was terminated by electroactive quininoid moiety. Prior to thiol molecule treatment, the characterisitc reversible redox peaks of the electroactive quininoid group was observed, while the reduction peak was dramatically shifted upon a treatment of GSH. This sensor showed the capability to detect the GSH in solution in the range of 1 mM $\sim$ 100 aM. We believe that this strategy will provide an important tool for accurate, sensitive, rapid, and low-cost determination of GSH.