Mn掺杂ZnS/ZnS核壳量子点磷光猝灭法测定铜离子

Phosphorescence quenching for detection of Cu^(2+) using core-shell ZnS/Mn:ZnS quantum dots

通过水热法合成了N-乙酰-L-半胱氨酸为稳定剂的锰掺杂硫化锌/硫化锌核壳量子点(NAC-ZnS/Mn:ZnS QDs),对其结构了进行表征。该核壳量子点的磷光强度随着Cu2+浓度的增加逐渐被猝灭,基于此构建了检测Cu2+的磷光探针。在最佳的实验条件下,Cu2+浓度与核壳量子点的磷光强度呈良好线性关系,检测的线性范围为0～10. 0μmol/L,检出限为8. 97 nmol/L,相对标准偏差是2. 8%。与其它金属离子相比,该种磷光探针对Cu2+具有良好的响应。并对掺杂核壳量子点与Cu2+相互作用可能的猝灭机制进行了探讨。磷光探针可应用于测定环境水样中微量Cu2+,回收率为98. 6%～105. 6%。

An environmental friendly NAC capped Mn dopedcore-shell ZnS/Zn squantum dots( NACZn S/Mn: ZnS QDs) were synthesized by hydrothermal process and characterized. The phosphorescence intensity of NAC-ZnS/Mn: ZnS QDs was gradually quenched with increasing concentration of Cu^2+,and the phosphorescence probe for detection of Cu^2+was proposed based on NAC-ZnS/Mn: ZnSQDs.Under the optimum conditions,the phosphorescence intensity of NAC-ZnS/Mn: Zn S QDs was linearly proportional to the concentrationof Cu^2+in the range from 0 to10. 0 μmol/Lwith the limit of8. 97 nmol/L and relative standard deviation of 2. 8 %. Meanwhile,the effect of foreign ions displayed a low interference response in the detection of Cu^2+ion. Moreover,based on phosphorescence decays of NAC-ZnS/Mn: ZnS QDs,the quenching mechanism between NAC-ZnS/Mn: ZnS QDs and Cu^2+ion was preliminarily discussed. The phosphorescence probe was successfully applied to detect trace Cu^2+in environmental water sample with good recoveries of 98. 60 %-105. 60 %.