采用锰掺杂硫化锌量子点室温磷光(RTP)探针,基于pb2+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25 μmol/L量子点溶液在Tris-HC1(10 mmol/L,pH 7.4)缓冲液中,反应时间为2 min时,检测pb2+的线性范围为0.25～1000 μmol/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pb2+的选择性检测,在稀释5倍人血浆中检测pb2+的线性范围为5～ 1000 μmol/L,检出限为0.48 μmol/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 1000 μmol/L, and the limit of detection was 0. 04 μmol/L (8. 3 uμg 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 μmol/L, and the limit of detection was 0. 48 μmol/L (Pb 99 μg/L), respectively.
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