石墨烯/聚苯胺复合膜修饰玻碳电极测定多巴胺

Electrochemical detection of dopamine on the graphene/polyaniline composite film modified electrode

采用原位聚合法制备石墨烯／聚苯胺复合物，利用X射线衍射技术和红外光谱进行表征，通过滴涂法制备修饰电极，对多巴胺进行电化学测定。分别对支持电解质、pH值和扫描速率等实验条件进行了优化，建立了测定多巴胺的新方法。实验结果表明，经石墨烯／聚苯胺修饰后的玻碳电极对多巴胺具有很好的催化氧化作用。在0．1mol／L磷酸盐缓冲溶液中（pH值为4．0），多巴胺的线性响应范围为8．0×101～5．0×10-mol／L，相关系数为0．994，检出限为9．8×10～mol／L。该法用于实际样品中多巴胺的测定，回收率为97．19／6～103．4％。

The graphene/polyaniline composite is synthesized by using an in situ polymerization procedure, and is characterized by XRD and FTIR. The composite is used to modify bare glass carbon electrode by drop-coating method, then dopamine（DA） is determined utilizing the composite film modified electrode via cyclic voltammetry. The experimental conditions, including the amount of supported electrolyte, pH value and scan rate, are optimized, and a new determination method of DA is established. The results show that the composite film modified electrode performs excellent electrocatalysis in redox behaviors of DA. In 0.1 mol/L phosphate buffer solution （pH 4.0）, the anodic peak current of DA is linear with its concentration in the range of 8.0 〉（ 10-7 -5.0 ）〈 10-a mol/L with the correlation coefficient of 0. 994, and the limit of detection is 9.8 X 10-8 mol/L. The proposed method is applied to determine DA in hydrochloride injection solution with recoveries of 97.1%-103.4%.