油溶性CdSe量子点荧光探针直接检测农药水胺硫磷  

Direct Determination of Isocarbophos by Using Oil-Soluble CdSe Quantum Dots as Fluorescence Probe

作　　者：黄珊[1] 马建强[1] 肖琦[1] 董明月[1] 李雪华[1] 罗秋玲[1] 

机构地区：[1]广西师范学院化学与生命科学学院,广西南宁530001

出　　处：《光谱学与光谱分析》2013年第10期2853-2857,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21203035);广西自然科学基金项目(2013GXNSFBA019029;2013GXNSFCA019005);第46批教育部留学回国人员科研启动基金项目;南宁市科学研究与技术开发项目(201107010B)资助

摘　　要：基于农药水胺硫磷对油溶性CdSe量子点荧光猝灭的现象,建立了一种简单、快速、直接检测农药水胺硫磷的新方法。在最佳实验条件下,油溶性CdSe量子点的荧光猝灭程度与水胺硫磷浓度在2.30×10-7～1.09×10-5 mol·L-1范围内呈较好的线性关系,相关系数为0.999 9,对水胺硫磷的检出限为1.1×10-7mol·L-1。本法已成功用于大米和小麦面粉样品中水胺硫磷农药残留的检测,加入回收率在93.3%～105.0%之间,结果满意。结合紫外-可见吸收光谱及时间分辨荧光光谱,探讨了水胺硫磷对油溶性CdSe量子点荧光猝灭的机理。研究结果表明,水胺硫磷能有效改变油溶性CdSe量子点的表面状态,增大了表面缺陷和非辐射重组的发生,从而使油溶性CdSe量子点的荧光猝灭。Abstract A simple, rapid and direct approach to isocarbophos determination was developed based on the fluorescence quenching of oil-soluble CASe quantum dots by isocarbophos. Under the optimized conditions, the linear range of oil-soluble .CASe QDs fluo- rescence intensity versus the concentration of isocarbophos was 2. 30 ×10^-7- 1.09 × 10^-5 mol. L^-1 , with a correlation coeffi- cient of 0. 999 9 and a limit of detection of 1.1 × 10^-7 mol.L^-1. The proposed method has been applied to the determination of isocarbophos in rice and wheat flour with standard recoveries of 93.3%-105.0%. The fluorescence quenching mechanism was further investigated by using UV-Vis absorption spectra and time-resolved fluorescence spectrum. The results indicated that the fluorescence quenching of oil-soluble CdSe QDs by isocarbophos was caused by the change of the surface state which resulted in the enhancement of the surface defect and the occurrence of the non-radiational recombination.

关 键 词：CDSE量子点 荧光探针 水胺硫磷 荧光猝灭 

分 类 号：O657.3[理学—分析化学]