纳米金胶修饰碳糊电极的制备及对多巴胺的电催化氧化

Fabrication of colloidal gold nanoparticle modified carbon paste electrode and its electrocatalytic oxidation to dopamine

合成了纳米金胶,并将纳米金胶用于制备碳糊修饰电极(Au/CPE),应用循环伏安法研究了多巴胺在纳米金胶碳糊修饰电极上的电化学行为。实验结果表明,纳米金胶对多巴胺的电化学氧化具有明显的催化作用,多巴胺在纳米金胶修饰电极上的氧化电位明显负移,循环伏安峰电流显著增大。缓冲溶液的pH值为4—7时,多巴胺在纳米金胶修饰电极上有很好的电化学响应。在扫速低于300 mV/s范围内,该响应为一表面控制过程,并初步探讨了电催化机理。在0.04 MpH6.37的B-R缓冲溶液中,氧化峰电流与多巴胺的浓度在6.0×10-8—2.6×10-7M的范围内呈较好线性关系,线性相关系数达0.9121。

In this paper,colloidal gold nanoparticle was synthesized and used to fabricate carbon paste electrode modified electrode（Au/CPE）.The electrochemical behavior of dopamine（DA） was studied by cyclic voltammetry.The Results show that colloidal gold nanoparticle has obvious catalytic activity to the electrocatalytic oxidation of dopamine.The electrochemical oxidation peak potential shifts negatively and peak current notably increases.Dopamine has good electrochemical response to the colloidal gold nanoparticle modified electrode at pH range of 4 to 7.At scan rate less than 300 mV/s,dopamine oxidation process is a surface-controlled process.The mechanism of dopamine oxidation is also explored.In 0.04 M pH 6.37 B-R buffer solution,the oxidation peak current is linear to dopamine concentration in the range of 6.0×10-8~2.6×10-7 M with a linear coefficient of 0.9121.