Synthesis of magnetic nanoparticles with immobilized aminophenylboronic acid for selective capture of glycoproteins

Aminophenylboronic acid (APBA)-functionalized magnetic iron oxide nanoparticles (Fe₃O₄ MNPs) were synthesized for the selective capture of glycoproteins from unfractionated protein mixtures. The morphology, adsorption, and recognition properties of the resultant particles were investigated and uniform size APBA-coated MNPs with a mean diameter of ∼15 nm and high magnetic saturation value of 30.6 emu g^-1 were obtained, which endued the adsorbent with a large surface area and convenience of isolation. The selectivity and binding capacity of APBA-coated MNPs were evaluated by using standard glycoproteins (cellulose and ovalbumin) and nonglycoproteins (bovine hemoglobin, bovine serum albumin and lysozyme) as model samples. Adsorption experiments and SDS-PAGE demonstrated that the APBA-coated MNPs had higher binding capacity and selectivity for glycoproteins compared to nonglycoproteins. In addition, the practicability of the as-prepared MNPs was further assessed by specific capture of ovalbumin from an egg white sample.