【摘要】 用巯基丙酸作为稳定剂,在水相中合成了CdS量子点。基于Cu2+对CdS量子点有显著的荧光猝灭作用,建立了检测水相中微量Cu2+的新方法。研究结果表明,在弱碱性的水溶液中,当Cu2+的浓度在1×10-5~3×10-4mol·L-1之间时,量子点的荧光猝灭强度△F/F与Cu2+的浓度之间很好地符合Stern-Volmer线性方程,线性相关系数为0.9952。方法的检出限为5.85×10-6mol·L-1,相对标准偏差为3.75%,加标回收率为95.5%~118.5%。讨论了量子点的荧光猝灭机理。在研究金属离子和一些化合物的干扰作用时,发现有的物质使量子点的荧光猝灭,有的物质却使量子点的荧光强度增强,发光强度对不同的物质就具有选择性。选择合适的掩蔽剂可以消除较强的离子干扰。更多还原

【Abstract】 In this paper,the CdS quantum dots were synthesized by using MPA as the stabilizer. Based on the quenching effect of the Cu2 +to the fluorescence of the CdS quantum dots,the analyzing method of the micro- quantity Cu2 +in water was established. The result shows that the relationship between the ΔF /F and the Cu2 +concentration was linearity according to the Stern- Volmer equation,while the Cu2 +concentrations were between the 1. 0 × 10- 5and 3. 0 × 10- 4mol·L- 1. The linear correlation coefficient was 0. 9952. The recovery of the method was between 95.5% and 118. 5%,the RSD was 3. 75%,and the detection limit was 5. 85 × 10- 6mol·L- 1. The quenching mechanism of the fluorescence was discussed. The interferences of some materials were investigated,the result showed that the fluorescence of the quantum dots were quenched by some materials but enhanced by others. The fluorescence intensity of the CdS quantum dots had different corresponding to the different metal ions. The proper masking agents could be used to eliminate the strong interference of some ions.更多还原