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 Cu²⁺ 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 Cu²⁺ ions in comparison to other metal ions tested. Using CdTe-L QDs, a rapid and facile analytical method was developed to determine Cu²⁺ ions in the concentration range of 5.16 ± 0.07 × 10^− 8 mol L^− 1–1.50 ± 0.03 × 10^− 5 mol L^− 1 with a detection limit of 1.55 ± 0.05 × 10^− 8 mol L^− 1. The nanosensor was successfully applied for the determination of Cu²⁺ ions in various water samples, and the results were compared with the standard method. .