交流阻抗技术研究巯基丙酸/中性红修饰电极上DNA的响应

Studies on the Response of Mercaptopropionic Acid/Neutral Red Modified Electrode to DNA by AC Impedance Technique

中性红(NR)可吸附在巯基丙酸自组装修饰金电极表面,并进而与DNA发生嵌插作用。以交流阻抗技术研究了DNA在巯基丙酸自组装/中性红修饰电极上的响应。结果表明,交流阻抗方法不仅可以反映DNA与小分子间发生的作用,还可以对DNA进行定量分析,响应在DNA浓度为0.4～8 mg.L-1范围内呈线性关系,相关系数r=0.997 3,检出下限为0.03 mg.L-1。该法是一种快速、简便、廉价的研究DNA及与小分子相互作用的方法。

The neutral red can be adsorbed to the surface of mercaptopropionic acid self-assembly modified electrode and then the embedding interaction with DNA will arise. In this paper, the AC impedance technique is applied to the study of the interaction between them. The results show that the AC impedance method can not only reflect the interaction of DNA with small molecules, but also be used for a quantitative analysis of DNA. The AC impedance response of the modified electrode is linear when the concentration of DNA in solution is within the range from 0.4 mg ·L^-1 to 8 mg·L^-1 with the regression coefficient r=0.997 3 and the detecting limit 0.03 mg·L^-1. This method is proved to be an efficient, simple and cheap way to study DNA and the interaction between small molecules.