基于氧化石墨烯修饰玻碳电极的多巴胺和尿酸的电化学检测

Electrochemical Detection of Dopamine and Uric Acid Based on Graphene Oxide Modified Glassy Carbon Electrode

将超声分散的氧化石墨烯(GO)悬浮液滴涂于玻碳电极(GCE)表面,制备成GO/GCE,并用扫描电子显微镜(SEM)和电化学阻抗谱(EIS)对GO/GCE进行表征,利用差分脉冲伏安法(DPV)、循环伏安法(CV)对多巴胺(DA)和尿酸(UA)进行了电化学测定。研究了pH对DA和UA电化学行为的影响并计算相关的动力学参数。结果表明:该修饰电极对DA和UA的氧化还原反应具有良好的电化学催化作用,在1.0~98.0μmol/L和0.5~90.0μmol/L范围内峰电流与DA和UA浓度呈良好的线性关系,检出限分别为0.50μmol/L和0.25μmol/L。而且可以在抗坏血酸(AA)共存下同时测定DA和UA。该传感器具有良好的选择性与稳定性,有望应用于DA和UA的同时测定。

The graphene oxide（GO）modified glassy carbon electrode（GO/GCE）was prepared by casting sonicated graphene oxide dispersion on the surface of glassy carbon electrode（GCE）,which was characterized by scan electron microscopy（SEM）and electrochemical impedance spectroscopy（EIS）.Differential pulse voltammetry（DPV）and cyclic voltammetry（CV）were employed to detect dopamine（DA）and uric acid（UA）.The effects of pH on the behaviors of DA and UA were studied and related kinetic parameter was calculated.Results indicated that the GO/GCE could catalyze the redox reaction of DA and UA.The DPV peak currents were liner with concentrations of DA and UA in the range of 1.0-98.0μmol/L and 0.5-90.0μmol/L,and the detection limits were 1.0μmol/L and 0.25μmol/L,respectively.Furthermore DA and UA can be simultaneously detected without interference of ascorbic acid（AA）.The presented sensor has excellent selectivity and stability,which is expected to be applied to detect DA and UA in real samples.