A highly selective and simple fluorescent sensor for mercury (II) ion detection based on cysteamine-capped CdTe quantum dots synthesized by the reflux method

Cysteamine (CA)-capped CdTe quantum dots (QDs) (CA-CdTe QDs) were prepared by the reflux method and utilized as an efficient nano-sized fluorescent sensor to detect mercury (II) ions (Hg2+). Under optimum conditions, the fluorescence quenching effect of CA-CdTe QDs was linear at Hg2+ concentrations in the range of 6.0-450nmol/L. The detection limit was calculated to be 4.0nmol/L according to the 3 sigma IUPAC criteria. The influence of 10-fold Pb2+, Cu2+ and Ag+ on the determination of Hg2+ was<7% (superior to other reports based on crude QDs). Furthermore, the detection sensitivity and selectivity were much improved relative to a sensor based on the CA-CdTe QDs probe, which was prepared using a one-pot synthetic method. This CA-CdTe QDs sensor system represents a new feasibility to improve the detection performance of a QDs sensor by changing the synthesis method. Copyright (c) 2014 John Wiley & Sons, Ltd.