Molecularly imprinted polymer based on magnetic porous cellulose for specific adsorption of tetracyclines: Preparation, characterization, property evaluation, and application

Abstract

A magnetic porous cellulose molecularly imprinted polymer (MPCMIP) based on tetracyclines was prepared with Fe3O4 as the magnetic core and porous cellulose as the carrier. The appearance, characteristic chemical bonds, crystal structure, thermal stability, and magnetism of MPCMIP were systematically characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and vibrating sample magnetometry. The adsorption performance of MPCMIP to tetracycline, demeclocycline, and minocycline were comprehensively investigated by static adsorption, dynamic adsorption, and adsorption experiments under different temperature and pH conditions. MPCMIP performed good adsorption performance and fast adsorption rate for tetracyclines, and adsorption quantity and efficiency of MPCMIP were four times and twice that of traditional molecularly imprinted polymer (MIP), respectively. It can be seen that the introduction of magnetic porous cellulose effectively improved the adsorption performance of the MIP. Moreover, MPCMIP showed good adsorption stability under different temperature. The adsorption properties of MPCMIP under neutral and alkaline conditions were better than those under acidic conditions. Selective experiment was conducted with the amoxicillin and levofloxacin as the coexisting interfering compounds for the three tetracyclines. The results showed that MPCMIP possessed good imprinting effect with the impact factor values for tetracycline, demeclocycline, and minocycline of 1.49, 1.66, and 3.14, respectively. Compared with interfering compounds, MPCMIP showed excellent selectivity to tetracyclines with the selectivity factor up to 36.9. Moreover, MPCMIP exhibited better selectivity towards tetracyclines than traditional MIP according to the higher imprinting and selectivity factors of MPCMIP. The simulation of hydrogen bonding interaction and electrostatic potential analysis determined that MPCMIP mainly adsorbed TCs through the hydrogen bonding and electrostatic interactions. The results of adsorption/desorption cycling experiments indicated that MPCMIP had good reusability with 95.5% of adsorption performance after four cycles. Finally, MPCMIP combined with high-performance liquid chromatography were triumphantly used to adsorb and detect the tetracycline, demeclocycline, and minocycline in river, beef, and milk samples. Furthermore, the MPCMIP method exhibited higher sensitivity, accuracy, and selectivity than the traditional method.