One-pot room temperature synthesis of CsPbBr₃ quantum dots-embedded molecularly imprinted polymer nanoparticles for sensitive sensing of ciprofloxacin

All-inorganic cesium lead halide perovskites quantum dots (PQDs) have emerged as promising candidates for developing high-performance sensing platforms, owing to their superior electrical and photophysical properties. However, the high-temperature synthesis and instability in polar solvent limit their practical application in water-phase environments, such as food safety monitoring. Herein, a versatile one-pot room temperature approach for the synthesis of molecular imprinted polymer-coated CsPbBr₃ quantum dots (CsPbBr₃@MIP) sol-gel method was presented. A highly luminescent PQDs was fabricated via a room temperature reaction and employed as a signal transducer, while the in-situ grown molecularly imprinted polymers (MIPs) acted as both protective shells and recognition units. Compared to bare CsPbBr₃ quantum dots, CsPbBr₃@MIP nanocomposites demonstrated an enhanced fluorescence stability and selectivity for ciprofloxacin (CIP). The green fluorescence (FL) emission of CsPbBr₃@MIP at 520 nm is quenched by CIP, enabling the development of a turn-off sensor for CIP detection. Under optimized conditions, the fluorescence intensity of the CsPbBr₃@MIP showed a strong linear correlation with CIP concentration in a wide range of 0.05–10.00 mg/L, and the limit of detection was as low as 0.03 mg/L. The relative standard deviation of 5 replicate determination for 1.0 mg/L CIP was 3.5%. Electron transfer between CIP and CsPbBr₃@MIP was asserted to be the primary FL quenching mechanism. The CsPbBr₃@MIP sensor was successfully applied to detect CIP in fresh fishes, yielding satisfactory recoveries of 91.3%–111.5% and high accuracy verified with the standard HPLC method.