L-半胱氨酸/纳米金修饰电极对硒的电化学检测

Electrochemical Determination of Se(Ⅳ) on A Glassy Carbon Electrode Modified by L-cysteine/gold Nanoparticle

利用纳米金修饰玻碳电极,再自组装上L-半胱氨酸制得L-半胱氨酸/纳米金复合修饰电极(L-cys/GNPs/GCE)。在硫酸介质中,采用循环伏安法(CV)考察硒(Ⅳ)在电极上的电化学行为。研究表明,L-cys/GNPs/GCE对硒(Ⅳ)的氧化还原具有较好的电催化作用,在峰电位0. 917 V处有灵敏的氧化溶出峰。此修饰电极的LSV响应与硒(Ⅳ)在0. 02～20μM范围内呈线性关系,检出限为5 n M(S/N=3)。此修饰电极具有良好的选择性、重现性和稳定性,可应用于实际样品中硒的测定。

The electrochemical behaviors of selenuim(Ⅳ)were detected by using L-cysteine/gold nanoparticle nanocomposite modified glassy carbon electrode(L-cys/GNPs/GCE).The electrocatalysis capability of L-cys/GNPs/GCE to Se(Ⅳ)was investigated by cyclic voltammetry(CV)technique in H 2SO 4 solution.Compared with the bare GCE,L-cys/GNPs/GCE exhibited outstanding electrocatalytic activity towards the redox reaction of Se(Ⅳ).The oxidation peak of Se(Ⅳ)at 0.917 V was used in the determination of Se(Ⅳ).The oxidation peak currents were linear to Se(Ⅳ)concentration in the range of 0.02~20μM with a detection limit of 5 nM.Moreover,L-cys/GNPs/GCE showed excellent selectivity,reproducibility and long-term stability,and was successfully applied to the determination of Se(Ⅳ)in real samples.