纳米金/聚多巴胺-还原氧化石墨烯复合膜修饰传感器的构建及对百草枯测定研究

Construction of gold nanoparticles/polydopamine-reduced graphene oxide composite sensor and its application in paraquat determination

实验利用氧化石墨烯和多巴胺分子制备了聚多巴胺-还原氧化石墨烯(PDA-rGO)复合膜,建立了高灵敏的纳米金/聚多巴胺-还原氧化石墨烯复合膜传感器(Au/PDA-rGO/GCE),用于检测百草枯并利用差分脉冲伏安法(DPV)和循环伏安法(CV)研究了百草枯在传感器上的电化学行为。首先,通过在碱性溶液中多巴胺的聚合反应来还原氧化石墨烯,以获得聚多巴胺改性的还原氧化石墨烯。其次,在电极表面滴涂10μL的聚多巴胺-还原氧化石墨烯悬浮液,在此基础上固定纳米金(GNPs)。结果表明,该传感器对百草枯有良好的电化学催化作用。实验优化了聚多巴胺-还原氧化石墨烯的制备条件和电极修饰条件。百草枯的还原峰电流在8.0×10^-8~3.0×10^-5 mol·L^-1范围内线性关系良好,检出限为2.2×10^-8 mol·L^-1。该修饰电极用于实际水和土壤样品中百草枯的测定,结果令人满意。

In this paper,we successfully prepared polydopamine(PDA)modified reduced graphene oxides(rGO)using graphene oxide(GO)and dopamine molecules(DA),and established a highly sensitive GNPs/polydopamine-reduced graphene oxide composite film sensor(Au/PDA-rGO/GCE)to apply for the paraquat determination.The electrochemical behavior of paraquat on the modified electrode was investigated by differential pulse voltammetry(DPV)and Cyclic Voltammetry(CV).First,graphene oxides(GO)nanosheets were reduced and surface functionalized by one-step oxidative polymerization of dopamine in basic solution to obtain the polydopamine modified reduced graphene oxides(PDA-rGO).Second,10μL of PDA-rGO suspension was dropped onto the surface of glassy carbon electrode,and then GNPs was anchored.The experiment optimized the preparation conditions of the PDA-rGO and the modification conditions of the electrode.Paraquat's reduction peak current has a good linear relationship with the concentration of paraquat in the range of 8.0×10^-8~3.0×10^-5 mol·L^-1,and the detection limit of paraquat is 2.2×10^-8 mol·L^-1.The modified electrode can be applied to the determination of paraquat in water and soil samples with satisfactory results.