先通过滴涂法制备纳米氧化铈-石墨烯(CeO₂-Gr)复合物修饰玻碳电极(GCE),再在含氯金酸(HAuCl₄)的缓冲溶液中,采用循环伏安法将Au(Ⅲ)还原到CeO₂-Gr表面,从而制得AuNPs/CeO₂/Gr/GCE。采用电化学阻抗谱法(EIS)对修饰电极进行电化学特性表征。研究了AuNPs/CeO₂/Gr/GCE快速、准确测定水环境中As(Ⅲ),采用差分脉冲溶出伏安法,探讨了氧化铈与石墨烯质量比、金纳米粒子沉积圈数、沉积时间和沉积电位及干扰离子等对测定结果的影响,并确定检测As(Ⅲ)的优化实验条件。在最优条件下,该电化学传感器对As(Ⅲ)具有良好的电流响应,其溶出伏安峰电流与As(Ⅲ)浓度的线性范围为13.35~387.15 μmol/L,检出限为4.74 μmol/L。在不同干扰离子存在的情况下,传感器对As(Ⅲ)的选择性较好。为了评估传感器的实际应用能力,以实验室自来水为样本进行As(Ⅲ)加标检测,加标回收率为90.5 %~99.2 %,表明该电化学传感器具有监测As(Ⅲ)的应用潜力。

Nano cerium oxide-graphene composite modified glassy carbon electrode (CeO₂-Gr/GCE) is prepared through a drop coating method.Furthermore,AuNPs/CeO₂-Gr/GCE is prepared through reducing Au(Ⅲ) onto the surface of CeO₂-Gr by cyclic voltammetry method in buffer solution containing chloroauric acid (HAuCl₄).The modified electrode is characterized by means of electrochemical impedance spectroscopy (EIS).A fast and accurate differential pulse stripping voltammetry method (DPSV) based on AuNPs/CeO₂-Gr/GCE is developed for determining As(Ⅲ) in the aqueous environment.Some influencing factors such as the mass ratio of graphene to cerium oxide,the circle number,time and potential of gold nanoparticle sedimentation,and interference ions are studied,and the optimal experimental conditions for detecting are determined.Under the optimal experimental conditions,As(Ⅲ) shows a good current response on this modified electrode.The electrode exhibits good linearity and reproducibility for As(Ⅲ) concentration in the range of 13.35-387.15 μmol·L^-1,with a detection limit of 4.74 μmol·L^-1.It is indicated by anti-interference experiment result that this modified electrode exhibits good selectivity for As(Ⅲ).As the modified electrode is served for the determination of As(Ⅲ) in laboratory tap water samples,the spiked recovery ranges from 90.5 % to 100.1 %,indicating a potential in monitoring As(Ⅲ).

白雪华(1998-),男,硕士生