应用循环伏安法和微分脉冲伏安法研究了6-糠氨基嘌呤(6-KT)和6-巯基嘌呤(6-MP)在汞电极上的电化学行为及与小牛胸腺DNA的相互作用.结果发现,6-KT和6-MP的循环伏安曲线均显示两对分别表征为扩散控制和吸附控制的氧化还原波.扩散控制波的氧化峰电流随6-取代嘌呤浓度在0.1~50.0μmol.L-1范围内呈现良好的线性关系.依据预吸附时间和溶液pH值对吸附控制波的还原峰电位和峰电流的影响,讨论了6-KT和6-MP在汞电极上的吸附机理.作者认为,6-KT乃通过部分插入作用与DNA结合,而6-MP与DNA间的相互作用为静电模式.

The electrochemical behavior of 6-furfurylaminopurine(6-KT) and 6-mercaptopurine(6-MP) on a mercury electrode has been investigated using cyclic voltammetry and differential pulse voltammetry.It is found that there are two pairs of redox waves for 6-KT and 6-MP on the mercury electrode controlled by diffusion and adsorption,respectively.The anodic peak currents of the diffusion-controlled wave increase with the adding concentration of 6-substituted purines.A good linear relationship for 6-KT and 6-MP is revealed in the concentration range from 0.1 to 50.0 μmol·L-1.Based on the effects of accumulating time and pH values on the cathodic peak potentials and currents of adsorption-controlled waves,their adsorption mechanism is discussed.The experimental results show that there are interactions of 6-KT and 6-MP with DNA via the intercalative mode partly and electrostatic action,respectively.