The synthesis of imprinted polymers based on Fe3O4 nanomaterials and the recognition of proteins

Abstract

A surface molecularly imprinted polymer (MIP-Fe₃O₄@AA) was prepared on a magnetic material (Fe₃O₄@AA) surface for the selective recognition and adsorption of bovine hemoglobin (BHb). The acrylic acid (AA) monomer was directly grafted to the surface of Fe₃O₄ through a simple coordination reaction between the carboxyl group of AA and unsaturated iron ions (Fe₃O₄@AA). Then the composite of MIP-Fe₃O₄@AA based on BHb was successfully synthesized by the surface grafting copolymerization method. The amounts of raw materials were optimized. The characteristics of the obtained MIP-Fe₃O₄@AA were determined by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). The adsorption capacity of MIP-Fe₃O₄@AA was evaluated and well fitted by the Langmuir model. The maximum theoretical adsorption capacity (Q_max) was calculated to be 117.27 mg g⁻¹ for MIP-Fe₃O₄@AA. The selectivity experiment showed that the MIP-Fe₃O₄@AA had an outstanding selectivity toward the template protein (BHb) with an imprinting factor of 4.43. The MIP-Fe₃O₄@AA was also used to capture BHb from the protein mixture and real sample with satisfactory results, which demonstrated its potential practical analytical performance.