Ternary deep eutectic solvent modified cadmium selenide quantum dots as a selective fluorescent probe for sensing of uranyl ions in water samples

Abstract

A single step hydrothermal approach for the synthesis of CdSe QDs using green precursor materials with the assistance of urea-thioglycolic acid-choline chloride ternary deep eutectic solvent (TDES-CdSe QDs) in an aqueous solution is reported. The fluorescent TDES-CdSe QDs probe was successfully applied to the fast and selective detection of uranyl ions. It was found that the fluorescence emission of the probe was dramatically quenched by uranyl ions, while other ions had no significant influence on the fluorescence intensity of the DES-CdSe QDs. The nanoprobe was systematically characterized by FTIR, XRD, TEM and EDX analysis. Some key factors affecting the performance of TDES-CdSe QDs probe were optimized using response surface methodology based on face centered central composite design. Under the optimal conditions, the DES-CdSe QDs probe provided a linear response to uranyl ions in the concentration range from 10 to 500 nM with a limit of detection 5.7 nM. The relative standard deviation (RSD%) of the developed method for five replicate determinations of uranyl ions at 100 nM was estimated to be 1.9%. In addition, the proposed method was successfully explored to the uranyl ions quantitation in environmentally water samples and desirable results were achieved.