谷胱甘肽包被的CdTe量子点作为荧光探针测定微量银

Glutathione-capped CdTe Quantum Dots as Fluorescence Probes for Determination of Silver

目的:建立了一种以CdTe量子点为离子探针测定微量银的新方法。方法:选择谷胱甘肽作为表面修饰剂,合成水溶性CdTe量子点。根据Ag+对CdTe量子点的荧光猝灭效应,用CdTe量子点作为荧光探针实现了对Ag+的定量检测。结果:在0.000 1 mol/L、pH值为7.4的磷酸缓冲溶液中,当量子点浓度为0.004 g/L时,反应时间为5 min,体系的相对荧光强度与Ag+浓度呈良好的线性关系,其线性范围为25.06～98.60μg/L,线性系数为0.995 7,检出限为0.15μg/L。结论:该法已成功应用于实体水样中微量银的测定。

Objective：To build a new method for the determination of trace of silver ion with CdTe quantum dots（QDs） as ion probe.Method：Water-soluble CdTe QDs were synthesized by chosing L-Glutathione（GSH） as modifying agent in aqueous solution.Based on the quenching of the fluorescence intensity of CdTe QDs by Ag＋,the CdTe QDs were used as fluorescence probes for the quantitative determination of amounts of Ag＋.Result：When the concentration of QDs was 0.004 g/L in the phosphate buffer at pH 7.4,the reaction time was 5 min,the degree of fluorescence quenching was linear with Ag＋ mass concentration in the range of 25.60~98.60 μg/L,with a linear correlation coefficient of 0.995 7.The limit of detection was 0.15 μg/L.Conclusion： This method has successfully applied to the determination of silver in water samples.