双色量子点多层膜用于水环境中 微量汞离子的定量检测

目的建立水环境中微量汞离子的定量检测方法。方法 通过层层自组装法将表面带有负电荷的Cd Te量子点与聚电解质PDDA交替沉积在石英板上,成功制备出双色量子点多层膜。在该方法中Hg2+对Cd Te量子点有荧光猝灭作用,据此发展了一种直接检测Hg2+的新型双色Cd Te量子点多层膜传感器。结果 实验结果表明:当Hg2+浓度在1.0×10-9~1.0×10-5mol/L范围时,量子点多层膜的荧光强度与Hg2+浓度之间有良好的线性关系,检出限为2.5×10-10mol/L。结论 与传统Hg2+检测方法相比,双色Cd Te荧光量子点多层膜作为一种新型传感器,具有快速、简单、选择性高和灵敏度高等优点,有望应用于水环境中痕量Hg2+的定量检测与早期预警。

Detection of mercury ions in water environment based on bi-color quantum dot multilayer films

Objective To establish a method for determination of mercury ions in water environment. Methods The functional multilayer films were assembled by layer-by-layer (LbL) deposition of oppositely charged CdTe quantum dot (QDs) and poly(dimethyldiallylemmonium chloride) (PDDA). The bi-color quantum dot multilayer films were used as fluoresce probes for the quantitative determination of trace amounts of Hg2 based on the evident quenching action of Hg2 on the fluorescence of CdTe QDs. Results Experimental results showed that the quenching in fluorescence intensity of multilayer films was linearly proportional to the concentration of Hg2 in the range of 1.0×10?9 to 1.0×10?5 mol/L and the detection limit was 2.5×10-10 mol/L. Conclusion Compared with the traditional Hg2 detection method, this method has the advantages of simplification, rapidness, high selectivity and high sensitivity. Furthermore, the proposed method was applied to the determination of trace Hg2 in water samples with satisfactory results.