A facile method for protein imprinting on directly carboxyl-functionalized magnetic nanoparticles using non-covalent template immobilization strategy

A facile strategy to prepare the core-shell magnetic imprinted nanoparticles for specific recognition of protein is presented. The core is carboxyl-modified Fe₃O₄ nanoparticles (Fe₃O₄@COOH) synthesized directly through a simple one-pot hydrothermal method. The formation of imprinted shell with specific recognition cavities includes three steps. Initially, the protein template is non-covalently anchored on Fe₃O₄@COOH. Next, the chemical oxidation of 3-aminophenylboronic acid takes place on the surface of Fe₃O₄@COOH-protein complex for further immobilization of template protein. Then, a thin imprinted layer is obtained on Fe₃O₄@COOH after the removal of the template protein. The resultant imprinted materials not only exhibit good dispersibility, uniform surface morphology, super-paramagnetic property, but also possess fast kinetics, high capacity, as well as favorable selectivity. In addition, the as-synthesized polymers could be used for six cycles of adsorption-desorption without obvious deterioration and applied to specifically separate and enrich target protein from real biological sample successfully. Furthermore, the result of versatility indicates that the facile preparation method is more suitable for basic proteins.