物理化学学报 >> 2005, Vol. 21 >> Issue (10): 1067-1072.doi: 10.3866/PKU.WHXB20051001

研究论文    下一篇

二茂铁及其与DNA复合物的电化学行为

陈灿辉; 李红; 朱伟; 张全新   

  1. 华南师范大学化学系, 广州 510631; 广州市疾病预防控制中心毒理科, 广州 510080
  • 收稿日期:2005-01-03 修回日期:2005-03-21 发布日期:2005-10-15
  • 通讯作者: 李红 E-mail:lihong@scnu.edu.cn

The Electrochemical Behavior of Ferrocene and Its Complex with DNA

CHEN Can-hui; LI Hong; ZHU Wei; ZHANG Quan-xin   

  1. Department of Chemistry, South China Normal University, Guangzhou 510631; University of Molecular Toxicology, Center for Disease Control and Prevention, Guangzhou 510080
  • Received:2005-01-03 Revised:2005-03-21 Published:2005-10-15
  • Contact: LI Hong E-mail:lihong@scnu.edu.cn

摘要: 在Tris-NaCl(pH=7.2)缓冲溶液中, 应用循环伏安法、微分脉冲伏安法、旋转圆盘电极实验、电化学阻抗谱等技术研究了二茂铁在旋转碳纳米管(CNT)修饰电极上的电化学行为及其与小牛胸腺DNA的相互作用. 结果表明, 二茂铁及其与双链DNA的电活性产物在静止的CNT修饰电极上均呈现一对基本可逆的氧化还原峰;在旋转电极上呈现出明显的极限扩散电流, 电化学阻抗谱呈现一个压扁的半圆. 二茂铁与DNA的作用在扩散控制过程中表现为峰电流和极限扩散电流随DNA浓度增大而减小;电化学控制过程则表现为电化学反应电阻随DNA浓度增大而增大, 条件电位下的速度常数也有一定程度的减小.

关键词: 二茂铁, 小牛胸腺DNA, 碳纳米管修饰电极, 旋转圆盘电极, 电化学阻抗谱

Abstract: The electrochemical behavior of ferrocene (Fc) and its interaction with calf thymus DNA at a rotating disk electrode modified with carbon nanotube (CNT) in Tris-NaCl buffer solution (pH=7.2) have been investigated by using cyclic voltammetry, differential pulse voltammetry, rotating disk electrode measurement, and electrochemical impedance spectrum. It is found that a pair of reversible redox waves for Fc are exhibited in the absence and presence of DNA on the immovable CNT-modified electrode. When the modified electrode is rotating, a distinct limiting diffusion current appears. Nyquist plot of Fc shows a suppressed half-circle in the absence and presence of DNA on the rotating CNT-modified electrode. Moreover, there exists an interaction of Fc with DNA under diffusion control based on the decrease of the peak current and limiting diffusion current with the increase of DNA concentration. On the other hand, the interaction between Fc and DNA under electrochemical control is also studied, the results show that the electrochemical reaction resistance of Fc exhibiting on the rotating disk electrode increases with the addition of DNA, and the rate constant at the formal potential decreases in the presence of DNA compared with that in the absence of DNA.

Key words: Ferrocene, Calf thymus DNA, Carbon-nanotube-modified electrode, Rotating disk electrode, Electrochemical impedance spectrum