纳米氧化铜-碳纳米管修饰玻碳电极同时检测邻、对苯二酚

Simultaneous Determination of Catechol and Hydroquinone by Copper Oxide Nanoparticles and Carbon Nanotubes Modified Glassy Carbon Electrode

以商品化纳米氧化铜和羧化碳纳米管作为玻碳电极修饰材料,结合了两种材料的放大电信号和电催化性能,所构建的复合物修饰电极可区分性质相近的同分异构体邻苯二酚和对苯二酚的信号,同时可进一步放大两种酚的峰电流。因此该基于纳米氧化铜和碳纳米管的电化学传感器可用于邻苯二酚和对苯二酚的同时检测。采用循环伏安法对复合物中两种材料的比例、修饰量以及支持电解质pH进行了优化:纳米氧化铜和碳纳米管质量比为5∶1,修饰量为9μL,pH=7.4的磷酸盐缓冲溶液被用作电解质溶液。在优化的条件下,邻苯二酚和对苯二酚的微分脉冲伏安扫描峰电流与浓度在6.0×10^-7~3.0×10^-3 mol/L范围内均呈良好的线性关系,检出限(S/N=3)分别为1.0×10^-7和1.6×10^-7 mol/L。该方法具有成本低、操作简便、快速的特点,对实际水样的加标回收率在94.6%~101.1%范围内,具有较好的实际应用前景。

Copper oxide nanoparticles and carboxylated multi-walled carbon nanotubes were used as modification materials for glassy carbon electrodes in this study.This nanocomposite combined the advantages of electrochemical signal amplification and electrocatalysis,and the as-prepared modified electrode could separate the redox peaks of catechol and hydroquinone and enlarge the peak currents further.Thus,this electrochemical sensor based on copper oxide nanoparticles and carbon nanotubes can be used for the simultaneous determination of catechol and hydroquinone.The ratio of copper oxide nanoparticles and carbon nanotubes in the nanocomposite,the cast volume and pH of the electrolyte are optimized via cyclic voltammetry.The optimal mass ratio between copper oxide nanoparticles and carbon nanotubes is 5∶1.The optimal cast volume is 9μL and phosphate buffer solution with pH=7.4 is used as the electrolyte.At the optimized conditions,the peak currents obtained with differential pulse voltammetric determination show good linear relationships with concentrations of catechol and hydroquinone in the range from 6.0×10^-7~3.0×10^-3 mol/L with detection limits of 1.0×10^-7 mol/L and 1.60×10^-7 mol/L(S/N=3),resepectively.This method is cheap,easy to operate and fast,and the recovery rates of practical water samples using this method are in a satisfactory range(94.6%~101.1%).Therefore,this proposed method has a good prospect of practical application.