• Title, Summary, Keyword: voltammetric sensor

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Development of Voltammetric Urea Sensors Based Poly(3-methylthiophene) film (Poly(3-methylthiophene)막 위에 urease를 고착시킨 Voltammetric Urea Sensor의 개발)

  • 박성호;진준형;홍석인;민남기
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.314-316
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    • 2000
  • Urea is detected as an indicator of renal disease in the human body. For these reasons, many biosensors for urea have been developed based on the enzymatic reaction of urea hydrolysis catalyzed by urease. Potentiometric method is applied reversible reaction system. But urea hydrolysis reaction may not has a reversible reaction mechanism in electrode surface. Therefore we applied to voltammtricmethod to obtain a sensitivity curve. The sensitivity of sensors was 34 ${\mu}$A/decade.

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Determination of Hydrogen Peroxide on Modified Glassy Carbon Electrode by Polytetrakis(2-aminophenyl)porphyrin Nanowire

  • Jeong, Hae-Sang;Kim, Song-Mi;Seol, Hee-Jin;You, Jung-Min;Jeong, Eun-Seon;Kim, Seul-Ki;Seol, Kyung-Sik;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • v.30 no.12
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    • pp.2979-2983
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    • 2009
  • Nanowires of polytetrakis(o-aminophenyl)porphyrin (PTAPPNW) were fabricated by electrochemical polymerization with the cyclic voltammetric method in anodic aluminum oxide (AAO) membranes. The glassy carbon electrode (GCE) modified by PTAPPNW, single-walled carbon nanotubes (SWNT) and Nafion as a binder was investigated with voltammetric methods in a phosphate buffer saline (PBS) solution at pH 7.4. The PTAPPNW + SWNT + Nafion/GCE exhibited strongly enhanced voltammetric and amperometric sensitivity towards hydrogen peroxide ($H_2O_2$), which shortened the response time and enhanced the sensitivity for $H_2O_2$ determination at an applied potential of 0.0 V by amperometric method. The PTAPPNW + SWNT + Nafion/GCE can be used to monitor $H_2O_2$ at very low concentrations in biological pH as an efficient electrochemical $H_2O_2$ sensor.

Voltammetric Studies of Anion Transfer Reactions Across a Microhole Array-Water/PVC-NPOE Gel Interface

  • Hossain, Md. Mokarrom;Girault, Hubert H.;Lee, Hye-Jin
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1734-1740
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    • 2012
  • Voltammetric characterization of hydrophilic anion transfer processes across a 66 microhole array interface between the water and polyvinylchloride-2-nitrophenyloctylether gel layer is demonstrated. Since the transfer of hydrophilic anions including $Br^-$, $NO_3{^-}$, $I^-$, $SCN^-$ and $ClO_4{^-}$ across the liquid/gel interface usually sets the potential window within a negative potential region, a highly hydrophobic organic electrolyte, tetraoctylammonium tetrakis(pentafluorophenyl)borate, providing a wider potential window was incorporated into the gel phase. The transfer reaction of perchlorate anions across the microhole-water/gel interface was first studied using cyclic voltammetry and differential pulse voltammetry. The full voltammetric response of perchlorate anion transfer was then used as a reference for evaluating the half-wave transfer potentials, the formal transfer potentials and the formal Gibbs transfer energies of more hydrophilic anions such as $Br^-$, $NO_3{^-}$, $I^-$, and $SCN^-$. The current response associated with the perchlorate anion transfer across the micro-water/gel interface versus the perchlorate concentration was also demonstrated for sensing applications.

Detection of Pesticide Thiram in Plant Leafs Using Voltammetric at Nanotube Electrode (나노튜브전극을 사용한 전압전류법에 의한 식물잎에서 살충제 검출)

  • Lee, Chang-Hyun;Ly, Suw-Young
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1335-1341
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    • 2010
  • Voltammetric diagnostics of pesticide thiram was studied in plant leafs in vivo fluid with DNA immobilized on a carbon nanotube electrode (DCE). Sensor properties of carbon nanotube (CE) and DNA immobilized nanotube were compared. DCE was more effective than CE in target detecting. The parameters such as pH strength, stripping accumulation, amplitude, and increment potential were examined to find the optimum condition for detection of pesticide thiram in a sesame leaf. The optimized conditions were as follows 550 Hz frequency, 0.15 V amplitude, 0.005 V increment potential, -1.2 V initial potential, 4.78 pH, 500 sec accumulation time. Under optimum condition, the detection limit of thiram was attained at 0.01ng/L.

Diagnostic Assay of Toxic Zinc in an Ex Vivo Cell Using Voltammetry

  • Ly, Suw-Young;Yoo, Hai-Soo
    • Toxicological Research
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    • v.28 no.2
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    • pp.123-127
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    • 2012
  • Voltammetric detection of the toxic Zn ion was investigated using a fluorine-doped graphite pencil electrode (FPE). It is notable from the study that pencils were used as reference and working electrodes. In all the experiments, a clean seawater electrolyte solution was used to yield good results. The analytical working range was attained to 10 ${\mu}gL^{-1}$. The optimized voltammetric condition was examined to maximize the effect of the detection of trace Zn. The developed sensor was applied to an earthworm's tissue cell. It was found that the methods can be applicable to in vivo fluid or agriculture soil and plant science.

A Novel Sensor Based on Electropolymerization Poly(safranine) Film Electrode for Voltammetric Determination of 4-Nitrophenol

  • Liu, Xing-Yuan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1182-1186
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    • 2010
  • A novel poly(safranine)-modified electrode has been constructed for the determination of 4-nitrophenol (4-NP) in natural water sample. The electrochemical behavior of poly(safranine) film electrode and its electrocatalytic activity toward 4-NP were studied in detail by cyclic voltammetry (CV) and adsorptive linear stripping voltammetry (LSV). All experimental parameters were optimized and LSV was proposed for its determination. In optimal working conditions, the reduction current of 4-NP at this poly(safranine)-modified electrode exhibited a good linear relationship with 4-NP concentration in the range of $8.0{\times}10^{-8}$ to $4.0{\times}10^{-5}mol\;L^{-1}$. The detection limit was $3.0{\times}10^{-8}mol\;L^{-1}$. The high sensitivity and selectivity of the sensor were demonstrated by its practical application for the determination of trace amounts of 4-NP in natural water and fruit samples.

Assay of In Vivo Chromium with a Hollow-fiber Dialysis Sensor

  • Ly, Suw-Young;Yoo, Hai-Soo;Jung, Min-Ki;Ko, Kwang-Hee;Kim, Byung-Jin;Lee, Ki-Chul;Choi, Byung-Min
    • Toxicological Research
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    • v.26 no.3
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    • pp.233-236
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    • 2010
  • The analytical in vivo chromium ion was searched for using a voltammetric hollow-fiber dialysis sensor via square wave stripping voltammetry (SW), cyclic voltammetry (CV), and chronoamperometry. Under optimum parameters, the analytical results indicated linear working ranges of 50~400 mg/l CV and $10{\sim}80\;{\mu}g/l$ SW within a 30-sec accumulation time. The analytical detection limit (S/N) was $6.0\;{\mu}g/l$. The developed method can be applied to in vivo tissues and in ex vivo toxicity assay, as well as to other materials that require chromium analysis.

The way to standardize electronic tongue system using IEEE 1451.4 (IEEE 1451.4를 이용한 전자혀 시스템의 표준화 방안)

  • Kim, Dong-Jin;Kim, Jeong-Do;Byun, Hyung-Gi;Ham, Yu-Kyung;Han, Dong-Won
    • Journal of Sensor Science and Technology
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    • v.14 no.6
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    • pp.444-454
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    • 2005
  • The IEEE 1451.4 standards defines an architectural model for interfacing smart transducers for sensors & actuators. This standard allows analogue transducers to communicate their identification and calibration data in a digital format. A digital format is called the TEDS (transducer electronic data sheet). However, the standard template TEDS of IEEE 1451.4 do not supports sensors to use in electronic tongue system, such as arrayed-potentiometric and voltametric sensors. In this paper, a solution to standardize sensors for E-Tongue (electronic tongue) and electronic tongue systems is presented.

Voltammetric Determination of Dopamine with the N-Hydroxysuccinimide Modified Carbon Paste Electrode (N-히드록시숙신이미드로 수식한 탄소반죽전극을 이용한 도파민의 전기화학적 측정)

  • Yoo Jae Hyun;Yoo Byung Wook;Kim Soon Shin;Uhm Jung Hee;Nam Hakhyun;Cha Geun Sig
    • Journal of the Korean Electrochemical Society
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    • v.4 no.3
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    • pp.109-112
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    • 2001
  • An activated carbon paste electrode was modified with the N-Hydroxysuccinimide(NHS) layer and applied to determine the dopamine in the presence of an excess ascorbic acid using square-wave voltammetry. The electrochemical properties of the modified electrode were examined in the solution containing dopamine/ascorbic acid using cyclic voltammetry(CV): the separation between the oxidation peaks of dopamine and ascorbic acid was largely dependent on the pH of the sample solution and became maximum at pH 4.0. Hence, the square-wave voltammetric determination of dopamine was carried out in a pH 4.0, 100mM phosphate buffer saline(PBS) containing 140mM NaCl. The detection limit and response slop were improved from $1.0{\mu}M\;to\;5.0\times10^{-2}{\mu}M\;and\;from\;0.93{\mu}A/{\mu}M\;to\;6.1{\mu}A/{\mu}M$, respectively, upon modification of the electrode surface by NHS.