基于石墨烯/纳米ZrO2复合膜修饰电极测定苹果中残余对硫磷的研究

Determination of residual parathion in apples based on the graphene/nano ZrO2 composite film modified electrode

石墨烯作为“明星材料”,具有高导电性和高比表面积;二氧化锆对磷酸基团具有很好的吸附作用.将石墨烯和纳米二氧化锆分散液修饰到电极表面制备成一种纳米石墨烯/纳米ZrO2复合膜修饰的对硫磷电化学传感器,并对修饰剂的浓度、支持电解质的选择、溶液pH值、富集时间和富集电位等实验条件进行了优化.由于复合膜修饰电极综合了石墨烯的高导电性与纳米ZrO2的强吸附能力,对硫磷在修饰电极表面表现出富集时间短、电子转移速率快的特点.差分脉冲伏安法分析结果显示对硫磷在传感器上的氧化峰电流与其浓度在0.05~30μmol·L^-1范围内呈良好的线性关系,检测限达20 nmol·L^-1.用加标回收法测量苹果样品中对硫磷含量,回收率为99.1%~103.6%.

As a“Star Material”,graphene possesses excellent conductivity and high specific surface.ZrO2 particles shows good adsorption function to phosphate groups.In this paper,a nano ZrO2/graphene composite film modified electrode was fabricated to use as a parathion electrochemical sensor.Some experimental conditions,such as the concentration of the modifier,supporting electrolytes,pH of solution,accumulation time and accumulation potential,were optimized.Benefited from high conductivity of graphene and good adsorption of ZrO2,parathion electrochemical sensor exhibited short accumulation time and fast electron transfer rate at the graphene/ZrO2 modified electrode.The results of differential pulse voltammetric analysis indicated that the oxidation peak current of parathion kept good linear relationship with its concentration in the range of 0.05~30μmol·L^-1.The limit of detection is 20 nmol·L^-1.It was applied to detect the residual parathion of apple samples.The result with the recovery of 99.1%~103.6%was satisfactory.