石墨烯修饰玻碳电极对多巴胺的电催化氧化

通过3-巯丙基三乙氧基硅烷(METMS)将氧化石墨烯(GO)固载到玻碳电极(GCE)表面, 用电化学方法还原GO制备石墨烯修饰玻碳电极(rGO-METMS-GCE). 利用傅里叶变换红外光谱(FTIR)、 拉曼光谱(Raman)、 扫描电子显微镜(SEM)和原子力显微镜(AFM)等技术对GO和rGO-METMS-GCE的结构和表面形貌进行表征. 采用循环伏安(CV)和差分脉冲溶出伏安(DPV)法研究了rGO-METMS-GCE对多巴胺(DA)的电催化氧化性能及反应机理. 结果表明, 与裸GCE相比, DA在rGO-METMS-GCE电极上的氧化还原峰电流(i_pa和i_pc) 增大4倍, 氧化峰电位负移106 mV, 氧化峰与还原峰电位差(ΔE_p)从202 mV降低至66 mV, DA电化学氧化可逆性明显改善, 表明rGO-METMS-GCE对DA电化学氧化具有显著电催化作用. DA在rGO-METMS-GCE上的反应机理为单电子转移过程.

Electrocatalytic Oxidation of Dopamine at Graphene Modified Glass Carbon Electrode

The graphene oxide(GO) bonded on glass carbon electrode(GCE) using 3-mercaptopropyol trimethoxysilane(METMS) as molecular bridge were electrochemically reduced to reduced graphene oxide(rGO) to form graphene modified glass carbon electrode(rGO-METMS-GCE). GO-METMS-GCE and rGO-METMS-GCE were characterized by SEM, FTIR, Raman spectroscopy and AFM. The electrochemical performances of rGO-METMS-GCE were studied by cyclic voltammetry(CV) and differential voltammetry(DPV). The results show that the electrocatalytic oxidation current of dopamine(DA) on rGO-METMS-GCE is about 4 times that on bare GCE. The oxidation and reduction potential difference(ΔE_p) of rGO-METMS-GCE is 66 mV, lower than that of bare GCE(202 mV). The rGO-METMS-GCE has remarkable electrocatalytic activity toward dopa mine oxidation and the redox reversibility of dopamine on the rGO-METMS-GCE is improved greatly.