CdTe/CdS量子点荧光探针测定痕量汞(Ⅱ)

在水溶液中合成巯基乙酸修饰的CdTe/CdS量子点(QDs),再基于Hg2+与CdTe/CdS量子点的荧光猝灭作用,建立用CdTe/CdS量子点作为荧光探针检测微量汞的新方法,并用该方法测定水中汞的含量。研究表明,pH值为6.24的磷酸缓冲溶液中,量子点浓度为3.75×10-4mol/L时,Hg2+离子浓度在2.3～150μg/L范围与CdTe/CdS量子点荧光猝灭强度呈良好的线性关系,相关系数为0.9985,检出限为0.87μg/L,回收率为99.0%～107.5%。该方法检测效果好,可用于实际样品分析。

Determination of Mercury(Ⅱ)by CdTe/CdS Quantum Dots as Fluorescence Probes

The water-soluble CdTe/CdS quantum dots（QDs） was synthesized using thioglycolic acid（TGA）as stabilizer.A novel method for determination of Hg（Ⅱ） has been developed based on quenching of the fluorescence of CdTe/CdS QDs at 580 nm by Hg（Ⅱ） in aqueous solutions.The proposed method has been used for determination of trace amounts of mercury in water.The optimum reaction conditions is at pH equalling to 6.24 with phosphoric acid as buffer solution and a CdTe/CdS QDs concentration of 3.75×10^-4 mol/L.The quenched fluorescence intensity of CdTe/CdS QDs is linearly in proportion to the concentration of Hg（Ⅱ）from 2.3 to 150 μg/L with correlation coefficient r equaling to 0.998 5,The detection limit for Hg（Ⅱ） is 0.87 μg/L,with recovery of 99.0～107.5%.The method can be used in analysis of practical samples and obtain reliable results.