A novel ascorbic acid ratiometric fluorescent sensor based on ZnCdS quantum dots embedded molecularly imprinted polymer and silica-coated CdTeS quantum dots

Abstract Ascorbic acid (AA) is involved in many important biological processes in the body whose determination is of great value for the diagnosis and treatment of diseases. We constructed a novel ratiometric fluorescence sensor for specific recognition and sensitive ratiometric determination of AA. In this sensor, CdTeS quantum dots coated silica shell (CdTeS QDs@SiO2) to act as a reference and offer a built-in correction for environmental factors. ZnCdS quantum dots were encapsulated in a three-dimensional network imprinted polymer (ZnCdS QDs@MIP) to provide response signal. The fluorescence emission of ZnCdS QDs@MIP was selectively quenched in the presence of AA, and a good linear model was fitted based on the fluorescence intensity ratios of ZnCdS QDs@MIP and CdTeS QDs@SiO2 (F530/F705) and the concentrations of AA in the range of 1–500 μM with a detection limit of 0.78 μM. The reliability of the proposed sensor in the real samples analysis was investigated through the detection of AA in vitamin C tablets and satisfactory results were obtained.