巯基-β-环糊精/石墨烯复合膜电极对多巴胺的电化学行为研究

A Study on Electrochemical Behaviors of Thiol-β-Cyclodextrine/Graphene Composite Film Modified Electrode for Dopamine

利用β-环糊精的C(6)位羟基合成的巯基-β-环糊精(β-CD-SH)和石墨烯的混合物在金电极上制备复合修饰膜,用循环伏安法研究复合膜对多巴胺(DA)的电化学行为,实验结果表明,在pH=4.00的磷酸盐缓冲溶液中,氧化峰电流的变化与DA浓度在0.11～135μmol/L范围内呈良好线性关系,相关系数达0.991,检出限为1.1×10-7mol/L。用于模拟样品中DA的测定,回收率为98.2%～101.3%,效果较好。

A derivative of thiol group of β-cyclodextrin（β-CD-SH） was synthesized via replacing C（6） hydroxyl group on β-cyclodextrin.Furthermore,a kind of new composite film modified gold electrode was prepared by β-CD-SH combined with graphene.Then its electrochemical behaviors towards the oxidation of dopamine（DA） were investigated.The results showed that the composite film modified electrode could reduce the oxidation overpotential of DA in pH=4.00 phosphate buffer solution（PBS）,the peak current of oxidation was proportional to the concentration of DA.and a good linear relation from 0.11～135 μmol/L（r=0.991） with a detection limit of 1.1×10-7 mol/L was obtained.When the method was applied to determining DA in simulated samples,a good recovery of 98.2%-101.3% was obtained.