基于铜离子与DNA相互作用的铜离子检测

Detection of Copper Ion Based on the Interaction Between DNA Molecules and Copper Ions

利用铜离子(Cu^(2+))可与DNA分子中的碱基相互作用形成络合物的性质,将Cu^(2+)富集在DNA修饰电极表面,进而采用微分脉冲伏安法(DPV)实现了铜离子的检测.此外,由于乙二胺四乙酸(EDTA)对Cu^(2+)具有更强的络合能力,富集于DNA修饰电极表面的Cu^(2+)很容易被洗脱液中的EDTA络合,从而实现修饰电极的再生和重复利用.实验结果表明,在最佳实验条件下,Cu^(2+)浓度在2.0×10-6~1.0×10-5mol/L和2.0×10-5~1.0×10-4mol/L范围内与其相对还原峰电流强度(I-I0)呈良好的线性关系,且该传感器简单、稳定,可循环使用.

Copper ion（ Cu^（2＋）） is one of the essential trace elements of human,which plays an important role in life. However,excessive amounts of copper ions may cause serious damage to health. In this work,Cu^（2＋）ions were determined by differential pulse voltammetry（ DPV） based on its concentration on DNA modified electrode due to the complexation of Cu^（2＋）ions with the base of DNA. Furthermore,because ethylenediaminetetraacetic acid（ EDTA） shows stronger complexing ability to Cu^（2＋）ions than DNA,Cu^（2＋）concentrated on DNA modified electrode can be eluted with EDTA. Thus,the modified electrode was reusable. The results showed that under optimum conditions,the relative reduction current（ I-I0） was linear with the concentration of copper ions in the range of 2. 0 ×10-6—1. 0×10-5mol / L and 2. 0 ×10-5—1. 0×10-4mol / L. The proposed electrochemical sensor for Cu^（2＋）ions was simple,stable and reusable.