Valorization of molecularly imprinted polymer for the rapid and selective detection of levofloxacin in milk

Levofloxacin (LFX) is widely used in the dairy industry, which raises serious concerns about its residues in dairy products. Herein, we report the synthesis of a magnetically separable molecularly imprinted polymer (MMIP) for the selective extraction of LFX from milk samples. MMIP was prepared by surface imprinting polymerization and characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The MMIP presented high adsorption capacity, fast binding kinetics and good selectivity for LFX, with a recovery of 92.6% under the optimized conditions. The developed method showed excellent linearity from 0.1–0.50 µg L −1 , high precision and a low relative standard deviation (RSD) of 2.20%. High-performance liquid chromatography (HPLC) analysis confirmed the efficient extraction of LFX residues from milk samples. The MMIP showed an imprinting factor of 2.12, which indicated higher selective recognition than the non-imprinted polymer. Furthermore, the MMIP exhibited better reusability, maintaining the structural and functional integrity in five successive adsorption–desorption cycles. Although the developed platform showed efficient extraction of LFX from milk matrices, further studies involving structurally related antibiotics, biological validation and large-scale application are needed.