Study of CdTe quantum dots as fluorescence probe to detect trace amount of Pb2

The surface modified quantum dots(QDs) as fluorescence probe to quantitatively detect the Pb2+ in water phase was studied in the paper.Using the mercaptopropionic acid(MPA) as the stabilizer,the CdTe quantum dots were synthesized in water phase.Based on the quenching effect of the Pb2+ on the QDs fluorescence,the method for detecting trace Pb2+ using QDs as probe was established.The results showed that the relationship between the Pb2+ concentration and the quenching intensity of the QDs(ΔF) while the Pb2+ concentration ranged from 1.0×10-8 to 1.0×10-6 mol·L-1 was fairly linear,and the correlation coefficient was 0.997 2.The detection limit was 9.3×10-10 mol·L-1.The RSD was 5.9%,and the recovery rate was between 86% and 110%.The study of the interference of the metal ions showed that the method was highly selective.