• Title/Summary/Keyword: Quartz crystal analyzer(QCA)

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Electrochemical Detection of Hydrogen Peroxide based on Hemoglobin-DNA/pyterpy Modified Gold Electrode (Hemoglobin-DNA/pyterpy 박막을 이용한 과산화수소의 전기화학적 검출)

  • Lee, Dong-Yun;Choi, Won-Suk;Park, Sang-Hyun;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1295-1296
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    • 2008
  • Hydrogen peroxide ($H_2O_2$) biosensor is one of the most developing sensors because this kind of sensors is highly selective and responds quickly to the specific substrate. Hemoglobin (Hb) has been used as ideal biomolecules to construct hydrogen peroxide biosensors because of their high selectivity to $H_2O_2$. The direct electron transfer of Hb has widely investigated for application in the determination of $H_2O_2$ because of its simplicity, high selectivity and intrinsic sensitivity. An electrochemical detection for hydrogen peroxide was investigated based on immobilization of hemoglobin on DNA/Fe(pyterpy)$^{2+}$ modified gold electrode. The pyterpy monolayers were firstly an electron deposition onto the gold electrode surface of the quartz crystal microbalance (QCM). It is offered a template to attach negatively charged DNA. The fabrication process of the electrode was verified by quartz crystal analyzer (QCA). The experimental parameters such as pH, applied potential and amperometric response were evaluated and optimized. Under the optimized conditions, this sensor shows the linear response within the range between $3.0{\times}10^{-6}$ to $9.0{|times}10^{-4}$ M concentrations of $H_2O_2$. The detection limit was determined to be $9{\times}10^{-7}$ M (based on the S/N=3).

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Electrochemical Properties of Self-Assembled Viologen Monolayers Using Quartz Crystal Analyzer (QCA를 이용한 자기조립된 Viologen 단분자막의 전기화학적 특성)

  • Lee, Dong-Yun;Park, Sang-Hyun;Shin, Hoon-Kyu;Park, Jae-Chul;Chang, Jeong-Soo;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.04b
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    • pp.141-144
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    • 2004
  • Molecular self-assembled of surfactant viologens are recently interesting because they can be from functional electrodes as well as micelle assemblies which can be profitably utilized for display devices, electrochemical studies and electrocatalysis as electron acceptor or electron mediator. The electrochemical behavior of self-assembled viologen monolayer on Au electrode surface has been investigated with QCM which has been known as nano-gram order mass detector. A monolayer of viologen is immobilized on the gold electrode surface and the normal potentials corresponding to the to the successive one-electron transfer processes of the viologen actives are two peaks in 0.1mol/l phosphate buffer solution respectively. These result suggest that the viologen SAMs are stable and well-behaved monolayers.

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