Magnetic nanoparticles combining teamed boronate affinity and surface imprinting for efficient selective recognition of glycoproteins under physiological pH

Abstract

Boronate-functionalized surface imprinted nanoparticles that function under physiological pH would be highly desirable for specific enrichment of target glycoproteins. In this work, magnetic molecularly imprinted polymers integrated with low pKa teamed boronate affinity (Fe3O4@PGMA-TBA/MIPs) were fabricated for selective separation of glycoprotein at pH = 7.4. The teamed boronate affinity (TBA) was formed by boron-nitrogen (B-N) coordination between 1,6-hexamethylenediamine and 3-aminophenylboronic acid, and then was fixed on the surface of magnetic poly(glycidyl methacrylate) (Fe3O4@PGMA) through ring-opening reaction. After immobilizing the template glycoproteins (ovalbumin, OVA), surface imprinting layer was deposited onto Fe3O4@PGMA-TBA surface via redox polymerization of aniline, and Fe3O4@PGMA-TBA/MIPs with obvious core–shell-shell structure were prepared by removing template. Fe3O4@PGMA-TBA/MIPs were demonstrated with an imprinted polymer film (10–20 nm) and exhibited superparamagnetic property (Ms = 32 emu g−1) and magnetic stability after multiple regenerations. Besides, the results of 11B MAS NMR spectrum and zeta potentials confirmed the presence of TBA resulting from B-N coordination. Additionally, taking advantage of surface imprinting and TBA, as-prepared Fe3O4@PGMA-TBA/MIPs posed high binding capacity (190.7 mg g−1) and fast capture kinetics (50 min) toward OVA under physiological pH. More importantly, because of the TBA was electroneutral at pH = 7.4, Fe3O4@PGMA-TBA/MIPs not only exhibited superior specific recognition toward OVA (imprinting factor IF = 7.51), but also maintained the activity of OVA from practical samples analysis. Therefore, this work opened up a universal route for developing intelligent controllability molecular imprinting materials for the specific separation of glycoproteins in biomedical filed under physiological pH.