Mercaptopropionic acid capped CdSe/ZnS quantum dots as fluorescence probe for lead(II)
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MPA stabilized CdSe/ZnS NCs was applied as a fluorescent probe for the sensitive detection of Pb2+ in water. The microreaction was demonstrated as a facile method for the reproducible synthesis of CdSe/ZnS NCs with a high quantum yield. The good stability of CdSe/ZnS NCs was proved by the significant maintaining of photoluminescent (PL) after the ligand exchange with MPA, and was further demonstrated by the excellent PL property in water solution with various pH values. The cation exchange of Zn with Pb led to the linear quenching of PL with the concentration of Pb2+, which provided as an opportunity to apply MPA stabilized CdSe/ZnS NCs as fluorescent probes for Pb2+. A facile method by adjustment of QDs concentration was demonstrated as a suitable way to approach different detection limits. The detection limits of 0.03 and 3.3 μM were achieved by setting QDs solutions with the absorbance of the first exciton peak as 0.05 and 0.15, respectively.
KeywordsQuantum dots Fluorescent probe Lead detection CdSe/ZnS Sensor Environment
Authors appreciated the financial supports from the Fundamental Research Funds for the Central Universities (WJ0913001), the Focus of Scientific and Technological Research Projects (109063), the State Key Laboratory of Chemical Engineering at ECUST (SKL-ChE-08C09), and National Nature Science Foundation of China (51172072).