高等学校化学学报

高等学校化学学报 ›› 1997, Vol. 18 ›› Issue (5): 706.

• 论文 • 上一篇    下一篇

硫堇衍生化自组装膜修饰金电极的电化学性质及其对抗坏血酸的电催化氧化

徐静娟, 方惠群, 陈洪渊   

  1. 南京大学化学系, 南京, 210093
  • 收稿日期:1995-04-23 出版日期:1997-05-24 发布日期:1997-05-24
  • 通讯作者: 陈洪渊.
  • 作者简介:徐静娟, 女, 28岁, 硕士研究生.
  • 基金资助:

    国家自然科学基金;江苏省自然科学基金

The Electrochemical Characteristics of Gold Electrode Modified by Thionine Covalently Bound to Self-assembled Cysteamine Monolayer and Its Electrocatalytic Oxidation for Ascorbic Acid

XU Jing-Juan, FANG Hui-Qun, CHEN Hong-Yuan   

  1. Deptartment of Chemistry, the State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjng, 210093
  • Received:1995-04-23 Online:1997-05-24 Published:1997-05-24

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被引次数

74

摘要： 将硫堇共价键合到自组装在金电极表面的半胱胺单分子层上,制成了衍生化自组装单分子膜修饰电极,并用电化学方法研究了它的电化学性质.循环伏安图显示其在pH＝7.7的磷酸盐缓冲液中,于－0.45～＋0.50V(vs.SCE)范围内有2对氧化还原峰.峰电位分别为Epa1＝214mV。Epc1＝82mV,Epa2＝－75mV,Epc2＝－160mV(vs.SCE).pH在5.0～9.0范围内,峰1有2个质子参与反应,峰2有1个质子参与反应.它的表面电子转移速率常数ks＝0.02S－1.此膜对抗坏血酸的氧化有催化作用,其氧化过电位较在裸金电极上降低了约250mV.催化电流与抗坏血酸的浓度在1.0×10-6～4.0×10-3mol/L范围内呈良好的线性关系.抗坏血酸催化氧化的异相速率常数为2.68×10-3cm/s.

关键词: 自组装, 电催化氧化, 硫堇, 化学修饰电极, 抗坏血酸

Abstract: Agold electrode modified by thionine covalently bound to self-assembled cysteamine monolayer (Th-SAM) has been prepared.The electrochemical properties of this ThSAMmodified electrode was investigated by electrochemical methods.There were two redox couples when it was swept in the range of -0.45-+0.50 V(vs.SCE) by cyclic voltammetry.As to pH7.7, the peak potentials were Epa1＝214mV。Epc1＝82mV,Epa2＝－75mV,Epc2＝－160mV, respectively.The participating number of proton was 2 for peak 1 and 1 for peak 2 in the pHrange between 5.0 and 9.0.The surface electron transfer rate constant(ks)of peak 2 was 0.02 s-1.The Th-SAMmodified electrode could be successfully used for the electrocatalytic oxidation of ascorbic acid and the catalytic currents increased linearly with the ascorbic acid concentration in the range of 1.0 ×10-6-4.0×10-3 mol/L-The heteroge neous electron transfer rate constant was about 2.68×10-3 cm/s.

Key words: Self-assembly, Electrocatalytic oxidation, Thionine, Chemically modified electrode, Ascorbic acid

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