Surface protein imprinted magnetic nanoparticles for specific recognition of bovine hemoglobin

Molecular imprinting for the detection of protein has gained great interest in recent years. For this purpose, we prepared magnetic molecularly imprinted polymers (MIPs) for the recognition of bovine hemoglobin (BHb) through the surface imprinting technique with two-stage core–sell sol–gel polymerization on the surface of silica modified Fe3O4 nanospheres. 3-Aminopropyltriethoxylsilane and octyltrimethoxysilane were chosen as monomers to construct the MIP layer. The morphology and structure property of prepared nanoparticles were characterized by TEM, X-ray diffraction, Fourier transform infrared spectrometry, and the vibrating sample magnetometer. The obtained magnetic MIPs with high saturation magnetization (60 emu g−1) made it easy to separate the target protein from solution by an external magnetic field. The adsorption and recognition performance of this magnetic MIPs was discussed through adsorption kinetics, adsorption isotherms, special selectivity, reusability and reproducibility tests. It turned out that the magnetic MIPs showed a relatively high adsorption capacity of 124.86 mg g−1 and excellent selectivity towards BHb with a separation factor of 1.99. Moreover, the adsorption capacity of magnetic MIPs was not significantly reduced after three continuous adsorption and elution processes, which indicated their good reusability for at least three repeated cycles.