Thiourea functionalized CdSe/CdS quantum dots as a fluorescent sensor for mercury ion detection

CdSe/CdS quantum dots (QDs) functionalized by thiourea (TU) were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid (TGA). It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg2+. The quantitative detection of He with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg2+ added in the range of 1-300 mu g L-1. A detection limit of 0.56 mu g L-1 was achieved. The sensor showed superior selectivity for Hg2+ and was successfully applied to the determination of mercury in environmental samples with satisfactory results. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.