CdTe量子点作荧光探针检测微量铅的方法研究

Study of CdTe Quantum Dots as Fluorescence Probe to Detect Trace Amount of Pb^(2+)

研究了用表面修饰的CdTe量子点作荧光探针检测水相中的微量铅离子。以巯基丙酸为稳定剂,在水相中合成了CdTe量子点。基于Pb2+对CdTe量子点有显著的荧光猝灭作用,用CdTe量子点作荧光探针,建立了水相中微量Pb2+的定量检测方法。研究结果表明:在优化的实验条件下,当Pb2+浓度在1.0×10-8～1.0×10-6 mol.L-1范围内时,量子点的荧光猝灭强度(ΔF)与Pb2+的浓度之间有良好的线性关系,线性相关系数为0.997 2,计算此方法的检出限为9.3×10-10 mol.L-1,相对标准偏差为5.9%,回收率为86%～110%。同时研究了常见金属离子的干扰作用,结果表明所建立的方法具有很好的选择性。

The surface modified quantum dots （QDs） as fluorescence probe to quantitatively detect the Pb2＋ in water phase was studied in the paper. Using the mercaptopropionic acid （MPA） as the stabilizer, the CdTe quantum dots were synthesized in water phase. Based on the quenching effect of the Pb2＋ on the QDs fluorescence, the method for detecting trace Pb2＋ using QDs as probe was established. The results showed that the relationship between the Pb2＋ concentration and the quenching intensity of the QDs （AF） while the Pb2＋ concentration ranged from 1.0× 10^-8 to 1.0× 10^-6 mol. L-1 was fairly linear, and the correlation coefficient was 0. 997 2. The detection limit was 9.3× 10^-10 mol. L-1. The RSD was 5.90%, and the recovery rate was between 86% and 110%. The study of the interference of the metal ions showed that the method was highly selective.