A novel fluorescent sensor for mercury (II) ion using self-assembly of poly(diallyl dimethyl ammonium) chloride functionalized CdTe quantum dots

摘要

Poly(diallyl dimethyl ammonium) chloride (PDDA) functionalized CdTe quantum dots (QDs) (PDDA-CdTe QDs) were synthesized through electrostatic self-assembly and used as fluorescence sensors. Mercury(II) ion (Hg2+) has a dramatic fluorescence quenching effect on the PDDA-CdTe QDs. Based on this quenching effect, a very sensitive fluorescence sensor for Hg2+ detection was established. Under the optimum conditions, the fluorescence quenching effect of PDDA-CdTe QDs was linear with the concentration of Hg2+ in the range from 0.006 mu mol L-1 to 1.0 mu mol L-1. The detection limit was calculated as 5.0 nmol L-1 according to the 3 sigma IUPAC criteria. This PDDA-CdTe QDs sensor system represents a new feasible method to improve the spectroscopic characterization of QDs used as Hg2+ sensors.