Molecularly imprinted CsPbBr3 quantum dot-based fluorescent sensor for trace tetracycline detection in aqueous environments

Abstract

All-inorganic halide perovskite quantum dots (IPQDs) have attracted considerable attention as an emerging fluorescent material owing to their excellent optical properties. However, due to the instability of IPQDs in polar solution, IPQDs have not been used in imprinting and detection in the aqueous phase. Herein, a sensitive, selective fluorescent sensor is reported, which combines luminescent CsPbBr₃ quantum dots (QDs) and molecularly imprinted polymers (MIPs) for trace tetracycline (TC) detection in aqueous environments. IPQDs@MIPs were constructed by encapsulating water-soluble CsPbBr₃ QDs in pre-prepared MIPs to avoid fluorescence quenching during conventional imprinted polymerization and elution, and the porous silicon matrix protected the QDs. IPQDs@MIPs solution emitted bright green fluorescence under UV lamp irradiation, confirming that IPQDs were stable in the aqueous phase and showed excellent selectivity for TC detection. Under optimal conditions, the fluorescence intensity of the IPQDs@MIPs had a good linear correlation with TC in the concentration range of 0.2–5.0 μM, and the detection limit was 28 nM. Furthermore, the imprinting factor of the IPQDs@MIPs was 4.87, and the mechanism of fluorescence quenching was mainly the electron transfer between TC and IPQDs@MIPs. The fluorescent sensor achieved satisfactory results in the standard addition recovery experiment of an actual water sample. This work paves the way for the further development of IPQDs in the field of analytical chemistry in a practical detection environment.