电化学预处理玻碳电极微分计时电位溶出法测定DNA中的嘌呤碱基及DNA浓度

研究了鸟嘌呤(G)、腺嘌呤(A)、鸟嘌呤核苷、腺嘌呤核苷和变性DNA在电化学预处理玻碳电极上的恒电流微分计时电位溶出行为. 实验结果表明, 用电化学方法预处理玻碳电极操作简单, 效果明显, 预处理玻碳电极对嘌呤及其核苷和DNA的吸附能力大大增强, 用微分计时电位溶出法可以得到灵敏的溶出峰, 溶出峰高(dt/dE)与其浓度在一定范围内呈良好的线性关系, 可用于嘌呤碱基及其核苷的定量检测和DNA浓度的测定. 将该方法应用于酸变性DNA样品中鸟嘌呤与腺嘌呤的同时测定, 选择性好、灵敏度高; 还可获得有关DNA损伤的一些信息.

Differential Chronopotentiometric Stripping Method for the Deter-mination of Purines and DNA Concentration Using an Electro-chemically Pretreated Glassy Carbon Electrode

The differential chronopotentiometric stripping method was used for the sensitive and selective determination of DNA and purines bases or the nucleosides concentrations in 0.1 mol/L phosphate buffer solution with pH=4.0 by using an electrochemically pretreated glassy carbon electrode.The results indicate that the electrochemically modified GCE could accumulate purines and ssDNA by effective adsorption and produce sensitive differential stripping peaks.The stripping peak heights(dt/dE) were linear with the concentrations of purine bases and denatured DNA in the suitable range.Some useful information related to DNA damage could be also acquired.