A novel method for the determination of Pb~(2+) based on the quenching of the fluorescence of CdTe quantum dots

摘要

A novel method for the determination of Pb~(2+) has been developed based on quenching of the fluorescence of thiol-capped CdTe quantum dots (QDs) by Pb~(2+) in aqueous solutions.Under optimum conditions,the relative fluorescence intensity was linearly proportional to the concentration of Pb~(2+) 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) Pb~(2+) solution (N= 5).As an application,the proposed method was successfully applied to the analysis of Pb~(2+) in food samples,and the results were satisfactory,i.e.consistent with those of flame atomic absorption spectrometry (FAAS).