A novel method for the determination of Pb2+ based on the quenching of the fluorescence of CdTe quantum dots

A novel method for the determination of Pb2+ has been developed based on quenching of the fluorescence of thiol-capped CdTe quantum dots (QDs) by Pb2+ in aqueous solutions. Under optimum conditions, the relative fluorescence intensity was linearly proportional to the concentration of Pb2+ between 2.0 x 10(-6) and 1.0 x 10(-4) mol L-1 with a detection limit of 2.7 x 10(-7)mol L-1. The relative standard deviation (RSD) was 4.6% for a 4.0 x 10(-5) mol L-1 Pb2+ solution (N = 5). As an application, the proposed method was successfully applied to the analysis of Pb2+ in food samples, and the results were satisfactory, i.e. consistent with those of flame atomic absorption spectrometry (FAAS).