Abstract
In recent years, perovskite quantum dots (PQDs) have successfully attracted widespread attention due to their excellent optical properties. However, the instability and toxicity problems of perovskite quantum dots are the main obstacles limiting their applications. In this work, bismuth-based perovskite quantum dots were synthesized by a ligand-assisted reprecipitation method, based on which a novel boric acid-functionalized bismuth-based non-toxic perovskite quantum dots fluorescent sensor (Cs3Bi2Br9-APBA) that can be stabilized in the ethanol phase was prepared by a boron affinity technique, and a fluorescent sensor (Cs3Bi2Br9-APBA) based on the covalent binding interaction between Cs3Bi2Br9-APBA and oxytetracycline (OTC) was developed. A highly selective and sensitive method for the detection of OTC was developed to solve the problem of poor stability and toxicity of perovskite quantum dots application. Under the optimal conditions, the fluorescence intensity of the synthesized Cs3Bi2Br9-APBA quantum dots was linear with the concentration range of 0.1 ~ 18 µM OTC, and the detection limit can reach 0.0802 µM. The fluorescence detection mechanism was explored and analyzed by spectral overlap analysis, suppression efficiency study of observed and corrected fluorescence, and fluorescence lifetime decay curve fitting, the mechanism of OTC detection by Cs3Bi2Br9-APBA was identified as the inner filter effect (IFE). In addition, the sensor successfully realized the quantitative detection of trace OTC in the environment, and our study provides a new idea for the preparation of green perovskite materials with high stability and selectivity.