锰掺杂硫化锌量子点室温磷光检测铅离子

Determination of Lead Ion Based on Quenching of Room Temperature Phosphorescence of Mn-doped ZnS Quantum Dots

采用锰掺杂硫化锌量子点室温磷光(RTP)探针,基于Pb^(2 1)对其磷光的猝灭现象进行选择性测定,考察了量子点溶液浓度、缓冲液体系及浓度、反应时间、干扰物质等多种因素影响,在最优条件下,即25μmol/L量子点溶液在Tris-HCl(10 mmol/L,pH 7.4)缓冲液中,反应时间为2 min时,检测Pb^(2-)-的线性范围为0 25～1000μmol/L,检出限为0.04μmol/L,方法的精密度和准确度良好。本方法简单、快速、灵敏度和选择性较好,线性范围较宽,可用于96孔板进行高通量检测,并成功应用于生物样品中Pb^(2-)的选择性检测,在稀释5倍人血浆中检测Pb^(2-)的线性范围为5～1000μmol/L,检出限为0.48μmol/L。

Room temperature phosphorescence（RTP） property of Mn-doped ZnS quantum dots （QDs） was explored to develop a novel method for selective detection of lead cation.The influence factors such as buffer kinds and their concentration,the concentration of Mn-doped ZnS QDs solution, reaction time and coexisting substances were studied.It was found that under optimized conditions, i.e.10 mmol/L Tris-HCl buffer at pH 7.4 and 2 min reaction time,the relative RTP intensity of the Mn-doped ZnS QDs was quenched linearly by lead cation in the concentration range from 0.25 to 1000μmol/L,and the limit of detection was 0.04μmol/L（8.3μg Pb/L）.This method was also applied to measure lead cation in biosamples using a high-throughput 96 well plate with a wide linear range,simpleness,rapidness,high sensitivity and selectivity,and cost effectiveness.The RTP was quenched linearly by lead cation in human plasma in the concentration range from 5 to 1000（imol/L, and the limit of detection was 0.48μmol/L（Pb 99μg/L）,respectively.