Non-Toxic Cs3bi2br9 Quantum Dots Molecular Imprinted Fluorescent Sensor with Boronate Affinity and Imprinting Selectivity for Selective Detection of Oxytetracycline

Abstract

In recent years, perovskite quantum dots (PQDs) have attracted much attention due to their excellent properties such as high fluorescence quantum yield, tunable emission wavelength, and simple preparation. However, the toxicity and poor selectivity of PQDs limit their application in the actual environment. In this work, a non-toxic bismuth-based perovskite quantum dot composite fluorescent sensor (Cs3Bi2Br9@SiO2-MIPs) was constructed for the detection of trace oxytetracycline (OTC) in the ethanol phase, which solves the toxicity problem of PQDs and realises the application of non-toxic PQDs in analysis and detection, the combination boronate affinity effect and molecularly imprinted technology enables highly selective detection of the sensor. The basic structure and optical properties of Cs3Bi2Br9@SiO2-MIPs were characterised by various characterisation methods, and the optimal detection conditions and fluorescence detection ability of Cs3Bi2Br9@SiO2-MIPs for OTC were determined. Under the optimal conditions, the Cs3Bi2Br9@SiO2-MIPs had a good linear relationship with OTC in the concentration range of 0.8 ~ 130 μM, and the detection limit was 0.32 μM. Furthermore, the fluorescence detection mechanism of the sensor was investigated in detail based on the fluorescence spectrum, fluorescence inhibition efficiency and the fluorescence lifetime decay curves, which ultimately revealed that the fluorescence detection mechanism of the sensor was a synergistic effect of inner filtration effect and fluorescence resonance energy transfer. The fluorescent sensor was successfully applied to the detection of trace OTC in real samples. This work provides a new idea for the construction of environmentally friendly and highly selective perovskite quantum dot fluorescent sensors.

Keywords: Bismuth-based perovskite quantum dots, Boronate affinity, Molecular imprinting, Fluorescence detection, Oxytetracycline