半胱氨酸包覆的CdTe量子点作为荧光离子探针测定痕量汞(Ⅱ)  

Cysteine-capped CdTe quantum dots as fluorescence probes for determination of mercury(Ⅱ)

作　　者：李梦莹[1] 周华萌[1] 董再蒸[1] 徐淑坤[1] 

机构地区：[1]东北大学化学系,辽宁沈阳110004

出　　处：《冶金分析》2008年第12期7-11,共5页Metallurgical Analysis

基　　金：国家自然科学基金(20675011)

摘　　要：以半胱氨酸为修饰剂，恒温100℃，水热法合成了CdTe量子点。此量子点对汞离子具有选择性响应。基于Hg^2＋对CdTe量子点荧光显著的猝灭作用，用CdTe量子点作为离子荧光探针实现了对痕量Hg^2＋的定量检测。于pH7．5的磷酸缓冲溶液中，当量子点的浓度（以Cd^2＋浓度计）为6．0×10^-5mol／L时，荧光猝灭程度与Hg^2＋的质量浓度在0．24～15．0μg／L范围内呈良好的线性关系，其线性相关系数为0．9992，方法的检出限为0．07μg／L（3σ）。用本方法测定水样中的汞，相对标准偏差为5．8％，加标回收率为95．0％～96．0％。CdTe quantum dots（QDs） that show selective actions on metal ions were prepared by means of cysteine as modifying agent in aqueous solution at 100 ℃. The CdTe quantum dots were used as fluorescence probes for the quantitative determination of trace amounts of Hg（Ⅱ） ions based on the evident quenching action of Hg^2＋ on the fluorescence of QDs. When the concentration of QDs was 6.0 × 10^-5 mol/L （representing in the concentration of Cd^2＋ ） in the phosphate buffer at pH 7.5, the degree of fluorescence quenching was linear with Hg（Ⅱ） mass concentration in the range of 0.24-15.0μg/L, with a linear correlation coefficient of 0. 999 2. The detection limit for Hg（Ⅱ） was 0.07 μg/L. The proposed method was successfully applied to the analysis of two real samples with the RSD of 5.8 % and recovery of 95.0%-96.0%.

关 键 词：半胱氨酸 量子点 荧光探针 荧光猝灭 汞 

分 类 号：O657.31[理学—分析化学]