Preparation and characterization of novel thermosensitive magnetic molecularly imprinted polymers for selective recognition of norfloxacin

Novel norfloxacin (NOR) thermosensitive magnetic molecularly imprinted polymers (T-MMIPs) were prepared with functional monomer methacrylic acid (MAA), temperature-response monomer N-isopropylacrylamide (NIPAM) and cross-linking agent N,N'-methylenebisacrylamide (MBA) by the surface imprinting technique. The silica layer and imprinted polymers layer coated on the surface of Fe3O4 nanoparticles, forming double-shell structure. The morphology and composition of the thermosensitive magnetic molecularly imprinted polymers were investigated by transmission electronmicroscope (TEM), Fourier transform infrared spectrometry (FT-IR), thermogravimetic (TGA), vibrating sample magnetometer (VSM), powder X-ray diffraction (XRD) and nitrogen adsorption analysis. The phase behavior and thermosensitivity of T-MMIPs were studied by swelling experiments and adsorption tests at different temperatures. And the adsorption performance of T-MMIPs at 35 degrees C were evaluated by adsorption experiments, including kinetic, isotherm and selectivity tests. The maximum capacity of T-MMIPs at 35 degrees C was 52.85 mg g(-1). In selective recognition tests, the T-MMIPs showed the highest selectivity for NOR among four components while the T-MNIPs showed similarly adsorption for all components. The prepared T-MMIPs have great potential in the detection and separation of norfloxacin due to the good temperature response, adsorption capacity, selectivity and reusability.