氧化石墨烯/硒化镉修饰电极电化学发光法测定铅(Ⅱ)

Electrochemiluminescent determination of lead ion by graphene oxide/CdSe quantum dot modified gold electrode

将氧化石墨烯(GO)和CdSe复合物修饰到金电极表面,得到了GO/CdSe修饰电极,研究了其电化学发光性质。结果表明,在强碱性溶液中,GO/CdSe修饰电极在鲁米诺溶液中会产生明显的电化学发光信号,而Pb^(2+)对该体系的电化学发光信号有较强的增敏作用,据此建立了检测Pb^(2+)的新方法。考察了GO/CdSe复合物的比例、缓冲溶液的pH、静置时间等条件对ECL强度的影响。在优化的实验条件下,Pb^(2+)浓度在1.0×10-11~1.0×10-7mol/L范围内与相对ECL强度呈现良好的线性关系。检测限(S/N=3)为3.3×10^(-12)mol/L,并用于人工湖水样中Pb^(2+)的测定。

The Graphene Oxide/CdSe quantum dots （GO/CdSe） compound modified gold electrode was prepared. The electrochemical luminescence （ECL） of this modified electrode was studied. The results showed that the GO/CdSe modified electrode had an obvious ECL signal of luminol systems in alkaline media, and lead ion could enhance ECL signal of the luminol system. Based on this phenomenon, a novel ECL method for the determination of lead ion was developed. Several experiment factors, such as solid - liquid ratio of GO/CdSe compound, pH of buffer solution, the static time, were optimized. Under optimized conditions, the ECL signal intensity depends linearly on the concentration of lead ion in the 1 × 10^-11 mol/L to 1. 1× 10^-7 mol/L. The detection limit （ S/N = 3 ） is 3. 3 × 10^ -12 mol/L. The proposed method has been successfully applied to determine lead ion in water samples of artificial lake.