基于Mn掺杂ZnS量子点室温磷光法测定水样中百草枯

Determination of Paraquat in Water Samples by Room Temperature Phosphorescence Method Based on Mn doped ZnS Quantum Dots

利用水相合成法制备了3-巯基丙酸（3-Mercaptopropionic Acid,MPA）包裹的Mn掺杂ZnS量子点（Quantum Dots,QDs）,基于该量子点的室温磷光性质,构建了一种快速、灵敏检测水样中百草枯（Paraquat,PQ）含量的新方法。方法无需添加任何除氧剂和诱导剂等复杂的预处理过程。在pH=7.4的磷酸盐缓冲溶液中,PQ通过静电作用可以猝灭Mn掺杂ZnS QDs在波长590nm处的磷光,且在一定范围内PQ的浓度与磷光猝灭强度（P0/P）呈良好的线性关系,线性范围为2.5-50μg/L,相关系数为0.994,方法检出限为0.769μg/L。该方法适用于不同水样中百草枯的痕量检测。

The 3-mercaptopropionate acid（MPA）-capped Mn-doped ZnS QDs（QDs）were prepared using water phase synthesis.Based on the room temperature phosphorescence properties of QDs,we estabilished a sensitive and rapid method of detecting paraquat（PQ）.The developed method was used at aqueous solution without adding any deoxidant and inducer.In phosphate buffer solution with pH=7.4,PQ enabled to quench the phosphorescence of Mn-doped ZnS QDs at 590 nm through electrostatic interaction.The quenching phosphorescence intensity had a good linear relationship with the concentration of PQ,the detection range from2.5to 50μg/L（correlation coefficient R=0.994）and a detection limit of 0.769μg/L was obtained.The method is very feasible for detection of trace PQ in water samples.