ZnS.Mn/SiO2量子点的表面聚乙烯吡咯烷酮修饰及其应用于海水中铅离子检测

摘要

制备了二氧化硅壳层修饰的ZnS.Mn量子点,基于聚乙烯吡咯烷酮( PVP)与二氧化硅表面硅羟基的作用,在纳米复合微粒表面进行了PVP的修饰,得到了在海水中荧光性能及胶体稳定性良好的ZnS.Mn/SiO2/PVP量子点。在Pb2+对所制备纳米微粒具有荧光猝灭效应的基础上,建立了用ZnS.Mn/SiO2/PVP 量子点作为荧光探针检测海水中微量铅离子的新方法。研究表明,量子点浓度为10-3 mol/L时,海水中离子浓度在10~100滋mol/L范围内与ZnS.Mn/SiO2/PVP量子点荧光猝灭强度呈良好的线性关系,相关系数为0.9946,检出限为8伊10-7 mol/L。%SiO2 coated ZnS: Mn quantum dots were synthesized and modified with PVP. The procedure of modification was based on the effect between amido band of PVP and hydroxyl of SiO2 . ZnS:Mn/SiO2/PVP quantum dots had an excellent fluorescence stability and colloid stability in sea water. Based on the fluorescence quenching of Pb2+ to ZnS:Mn/SiO2/PVP, a novel method for de-termination of Pb2+ in sea water was developed. With a concentration of 10 -3 mol/L, the quenched fluorescence intensity of ZnS:Mn/SiO2/PVP is linearly in proportion to the concentration of Pb2+ in sea water from 10 to 100 μmol/L. The correlation coefficient R is 0. 994 6, and the detection limit for Pb2+ in sea water is 8í10 -7 mol/L.