Biomimetic ratiometric fluorescence sensor based on perovskite quantum dots and carbon dots for ultrasensitive...

The development of high-performance fluorescence (FL) sensing platform for sensitive and selective monitoring ciprofloxacin (CIP) antibiotic residues is crucial for food safety and environmental protection. Herein, we present an innovative dual-response ratiometric FL sensor, fabricated from perovskite quantum dots (PQDs) and carbon dots (CDs) embedded within a molecularly imprinted polymer (MIP) (PQDs/CDs@MIP) via an efficient one-pot sol-gel method. The constructed PQDs/CDs@MIP sensor combines the specific recognition of MIPs with dual FL emission at 460 nm (CDs) and 518 nm (PQDs). Upon exposure to CIP, the blue FL can be enhanced while the green FL is quenched, and the FL intensity ratio (F₄₆₀/F₅₁₈) is linearly dependent on the CIP concentration. Benefiting from the biomimetic molecular recognition and the dual-signaling transduction, the developed sensor demonstrates excellent selectivity and ultra-high sensitivity, achieving a remarkably low limit of detection (LOD) of 0.005 μmol L^-1 in a wide concentration range of 0.01-30.0 μmol L^-1. The proposed sensor has been successfully applied to the quantitative determination of CIP in real aquatic products, with satisfactory recovery rates of 90.0 %-106.7 %. This work offers a promising new strategy for the development of ratiometric sensing system with dual-signaling modes for monitoring antibiotic residue.