一种多吡啶铜配合物与DNA相互作用的电化学研究

采用循环伏安法、微分脉冲伏安法、计时库仑法并结合紫外光谱法研究了一种电中性多吡啶铜配合物Cu（phen）（PC）（H2O）]（phen=1,10-邻菲罗啉,PC=2,6-吡啶二羧酸）与DNA的相互作用.紫外吸收光谱显示,配合物溶液加入DNA后,配合物的特征吸收峰减小,产生明显的减色效应,表明二者发生了相互作用.循环伏安结果表明配合物在玻碳电极呈现一对准可逆氧化还原峰.加入DNA后,配合物的峰电流明显减小,式电位发生正移,表明二者可能通过嵌插方式发生作用.微分脉冲伏安法考察了不同浓度的DNA对配合物的影响,表明以Cu（phen）（PC）（H2O）]作为电化学探针,能在3.3×10–6 mol/L~4.0×10–5 mol/L浓度范围内对DNA进行定量检测.计时库仑法进一步显示,配合物与DNA形成复合物后扩散系数明显降低了.

Electrochemical Studies on the Interaction between DNA and a Polypyridyl Copper Complex

The interaction between a polypyridyl copper complex Cu（phen）（PC）（H2O）（phen=1,10-phenan-throline,PC=2,6-pyridyl-dicarboxylato） and DNA was investigated by electrochemical methods and UV spectrophotometry.With addition of DNA,the characteristic absorption peak of Cu（phen）（PC）（H2O） was weakened,and a hypochromism was occurred,demonstrating the interaction between the copper complex and DNA.It was showed that the complex was an electroactive compound at glassy carbon electrode with a pair of quasi-reversible redox peaks.The interaction of DNA with Cu（phen）（PC）（H2O） caused the significant decrease of redox peak currents coupled with positive shift of formal potentials,indicating that Cu（phen）（PC）（H2O） might bind with DNA by an intercalation mode.Differential pulse voltammetry showed that the concentration of DNA could be qualified in the range of 3.3×10-6 mol/L ~ 4.0×10-5 mol/L via using Cu（phen）（PC）（H2O） as an electroactive probe.Chronocoulometry suggested that the diffusion rate of the complex was decreased obviously after interaction with DNA.