高等学校化学学报 ›› 1995, Vol. 16 ›› Issue (1): 31.

• 论文 • 上一篇    下一篇

修饰微带金电极上细胞色素C电极过程的热力学研究

蔡称心, 鞠熀先, 陈洪渊   

  1. 南京大学化学系, 南京 210008
  • 收稿日期:1994-01-31 修回日期:1994-06-02 出版日期:1995-01-24 发布日期:1995-01-24
  • 通讯作者: 蔡称心,男,28岁,博士研究生.
  • 作者简介:陈洪渊
  • 基金资助:

    国家自然科学基金;国家教育委员会博士点基金;青年基金

Studies on the Electrode Process thermodynamics of Cytochrome C at A Microband Gold Electrode Modified with 4, 6-Dimethy1-2-mercaptopyrimidine

CAI Chen-Xin, JU Huang-Xian, CHEN Hong-Yuan   

  1. Department of Chemistry, Nanjing University, Nanjing, 210008
  • Received:1994-01-31 Revised:1994-06-02 Online:1995-01-24 Published:1995-01-24

摘要: 研究了细胞色素C(Cyt.C)在一种新的电子转移促进剂4,6-二甲基-2-巯基嘧啶修饰微带金电极(DMMP/Au)上的氧化还原热力学;求得Cyt.C在DMMP/Au电极上电化学反应的标准电极电位E0'、熵变△S0、焓变△II0及Gibbs自由能的改变△G0值分别为:0.272V(vs.NHE)、-123.7J·mol-1·K-1、-63.1kJ·mol-1和-26.2kJ·mol-1(25℃,pH=7.0);同时,探讨了温度及pH值对Cyt.C电极反应热力学参数的影响。实验表明,碱性条件下E0'随温度的变化表现出与中性及弱酸性条件下不同的规律。

关键词: 微电极, 微带金电极, 细胞色素C, 4, 6-二甲基-2-巯基嘧啶, 热力学

Abstract: The redox thermodynamics of cytochrome Cat a 4, 6-dimethyl-mercaptopyrimidine(DMMP), a new electron transfer promoter of cytochrome C, modified microband gold electrode(DMMP/Au)was investigated by cyclic voltammetry. The thermodynamic param eters of the electron-transfer reaction of cytochrome Cat DMMP/Au electrode were estimated. The normal potential E0', the changes of entropy,enthalpy and Gibbs free energy,△S0,△H0and △G0, for cytochrome Cat 25℃ and pH 7.0 were 0.272 V(vs. NHE),-123.7 J· mol-1·K-1,-63.1 kJ·mol-1and -26.2kJ·mol-1, respectively. The effects of temperature and pHon the thermodynamic parameters of cytochrome Cwere discussed. The E0' vs.Tplot shows remarkable biphasic character in an alkaline solution with a turning point at ca.45℃, whereas in an acid or neutral solution the E0' values changed monotonically with temperature.

Key words: Microelectrode, Microband gold electrode, Cytochrome C, 4,6-Dimethyl-2-Mercaptopyrimidine, Thermodynamics

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