Ligand-Capped CdTe Quantum Dots as a Fluorescent Nanosensor for Detection of Copper Ions in Environmental Water Sample.

In this work, as a novel fluorescent nano-sensor, a ligand-capped CdTe QDs (CdTe-L QDs) was designed for the detection and quantification of Cu ions in environmental water samples. The synthesized QDs were characterized by transmission electron microscopy (TEM), thermo-gravimetric (TG) analysis, Fourier transform infrared (FTIR), UV-Vis spectrophotometry and fluorescence spectroscopy. Optical properties of the produced nanosensor were monitored by UV-Vis and fluorescence spectrophotometry. It was observed that fluorescence intensity of the produced nano-sensor selectively quenched by adding Cu ions in comparison to other metal ions tested. Using CdTe-L QDs, a rapid and facile analytical method was developed to determine Cu ions in the concentration range of 5.16 ± 0.07 × 10 mol L-1.50 ± 0.03 × 10 mol L with a detection limit of 1.55 ± 0.05 × 10 mol L. The nanosensor was successfully applied for the determination of Cu ions in various water samples, and the results were compared with the standard method. Graphical Abstract.