Preparation of ligand-capped CdTe quantum dots as a fluorescent nanosensor for detection of Cr(III) in aqueous solutions

Chromium is recognized as a serious environmental pollutant because of high toxicity. In this study, a ligand-capped CdTe QDs as a novel fluorescent nanosensor was designed for detection and quantification of Cr (III) ion in aqueous samples. Optical properties of produced nanosensor were monitored by UV–Vis spectrophtometry and fluorescence spectroscopy. It was observed that fluorescence intensity of produced nanosensor quenched selectively by addition of Cr (III) ion. The detection method based on this nanosensor possesses a fast response time of one minute for the determination of Cr (III) in the concentration range of 3.78× 10 -8 mol L−1 – 3.70× 10 -6 mol L−1 , with a detection limit of 2.03× 10 -8 mol L−1. The produced nanosensor was optimized and characterized by fourier transform infrared (FTIR), transmission electron microscope (TEM), ultraviolet-visible (UV–Vis) spectrophtometry and fluorescence spectroscopy. The size of the prepared nanosensor was estimated around 3 nm.