碱性品红及聚碱性品红修饰电极与DNA的相互作用

运用循环伏安法和紫外 可见吸收光谱法研究了碱性品红 (FuchsinBasic ,FB)和DNA的相互作用 ,并制备了聚碱性品红修饰的玻碳 (GC)电极 ,研究了DNA在此电极上的电化学行为。结果表明 ,室温下 ,在 0 1 0mol·L- 1 pH 7 0的B R缓冲溶液中 ,FB有一良好的氧化峰 ,FB与DNA混合后 ,在电位扫描范围内未出现新峰 ,而FB的氧化峰电流增大 ,峰电位基本不变。在聚碱性品红修饰GC电极上DNA出现了一对氧化还原峰 ,该峰随着扫描次数的增加而消失。紫外 可见特征吸收实验表明 ,加入DNA后 ,FB的峰形基本不变 ,吸光度降低 ,呈减色效应 ,但峰位不发生移动 ,并存在着一个等吸点 ,证明DNA与FB作用方式是静电作用和嵌插作用两种方式。

Electrochemical Study of Interaction of Basic Fuchsin and Poly(Basic Fuchsin) Modified Electrode with DNA

The interaction between DNA and basic fuchsin was studied by cyclic voltammetry and UV-Vis absorption spectroscopy. Poly (basic fuchsin) modified electrode was prepared and the electrochemical behavior of DNA on such an electrode was also studied. Under room temperature, basic fuchsin has a well-defined oxidation peak in 0.10 mol·L -1 B-R buffer solution of pH 7.0. After adding DNA in basic fuchsin solution, the current of the oxidation peak of basic fuchsin increases while its peak potential has no significant shift and no new peak appears. DNA has a pair of new redox peaks on the electrode modified by poly (basic fuchsin). The new peaks disappear rapidly with the increase of the times of scarning. The UV-Vis absoption spectra of basic fuchsin after adding DNA indicated that there was a hypochromic effect of DNA, an isoabsorption point at 570 nm was observed and the location of the absorption peak didn′t shift. It was showed that the binding models of basic fuchsin with DNA were intercalation binding and electrostatic binding.