Fluorescence enhancement of CdTe/CdS quantum dots by coupling of glyphosate and its application for sensitive detection of copper ion.

A novel fluorescent probe for Cu(2+) determination based on the fluorescence quenching of glyphosate (Glyp)-functionalized quantum dots (QDs) was firstly reported. Glyp had been used to modify the surface of QDs to form Glyp-functionalized QDs following the capping of thioglycolic acid on the core-shell CdTe/CdS QDs. Under the optimal conditions, the response was linearly proportional to the concentration of Cu(2+) between 2.4×10(-2)μg mL(-1) and 28μg mL(-1), with a detection limit of 1.3×10(-3)μg mL(-1) (3δ). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu(2+). The fluorescent probe was successfully used for the determination of Cu(2+) in environmental samples. The mechanism of reaction was also discussed.