Preparation and Recognition Performance of Fleroxacin Ratio Fluorescent Paper-based Sensor Based On Molecularly...

The pervasive concern regarding veterinary drug residues in food necessitates advanced detection solutions, particularly addressing limitations of conventional methods reliant on large-scale instrumentation that incur prolonged analysis duration, complex sample preparation, and lack of real-time on-site capability. A portable "single response-on" molecularly imprinted ratiometric fluorescent paper-based sensor was developed for quantifying fleroxacin (FLX) residues in animal-derived foods, wherein B, N-co-doped MXene quantum dot (B, N-MQD) was synthesized and combined with BCP-Eu as dual-emission fluorophores, while FLX- molecularly imprinted polymer (FLX-MIP) was engineered using functionalized Nano-SiO₂ as the carrier. Concentration-dependent fluorescence enhancement at 574 nm was exhibited with invariant reference signal at 411 nm, achieving a 36-fold lower detection limit (0.49 µM) versus the non-imprinted probe (17.78 µM) and linear response across 25.0 ~ 200.0 µM. When integrated with smartphone visualization, 25.0 ~ 350.0 µM linearity, 4.78 µM detection limit, and 89.80 ~ 96.44% recoveries were demonstrated in real samples, validating reliability for on-site screening. * Corresponding authors. E-mail: lisa4.6@163.com(Z. Liu), peter.zou@rid-lab.cn(P.T. Zou), hangc81@guet.edu.cn(G.-C. Han).