银掺杂L-脯氨酸修饰电极用于研究肾上腺素与DNA的相互作用

Study on the Interaction between Epinephrine and DNA with Ag-doped-poly L-Proline Modified Electrode

采用循环伏安方法将Ag^+与L-脯氨酸单体共聚合在玻碳电极表面制得银掺杂聚L-脯氨酸修饰电极,并应用该修饰电极研究了肾上腺素(EP)与双链DNA(dsDNA)之间的相互作用。试验发现:在pH 7.0磷酸盐缓冲溶液中,EP在修饰电板上有一个明显的氧化峰;当加入一定量的dsDNA后,EP的氧化峰电流明显下降。EP氧化峰电流的下降值(△i)与dsDNA的质量浓度在一定范围呈线性关系;dsDNA与EP相互作用形成了分子比为1比2的复合物,两者的结合常数为4.56×10~4。

Ag-doped poly L-proline modified glassy carbon electrode （Ag-PPro/GCE） was prepared by electrochemical copolymerization of Age and L-proline monomer on the surface of glassy carbon electrode by cyclic voltammetry, and the modified eietrode was applied to the study on the interaction between epinephrine （EP） and double strand DNA （dsDNA）. It was found that in PBS of pH 7.0, a sensitive oxidation peak of EP was observed at the modified electrode; and the current of this oxidation peak decreased obviously upon addition of dsDNA. I.inear relationship between the magnitude of decrease in peak current （△i） of EP and mass concentration of dsDNA was kept in definite range. A complex between dsDNA and EP with the molar ratio of 1 to 2 was formed, with binding constant of 4. 56 × 10^4.