Novel composites of multifunctional Fe₃O₄@Au nanofibers for highly efficient glycoprotein imprinting

A kind of surface glycoprotein imprinting over magnetic Fe₃O₄@Au multifunctional nanofibers (NFs) was developed and investigated. Magnetic Fe₃O₄@Au nanoparticles (NPs) as the core materials were modified consecutively with aniline, 3-aminophenylboronic acid (APBA) and acrylic acid to introduce boronic acids and polymerizable double bonds. With horseradish peroxidase (HRP) as a glycoprotein template, thin protein-imprinted films were fabricated via radical induced graft copolymerization of monomers on the surface of the multifunctional NFs. Experimental results show that the magnetic multifunctional Fe₃O₄@Au NFs can not only direct the selective occurrence of imprinting polymerization, but also drive glycoprotein templates into the polymer through reversible covalent complex formation. The results show that the imprinted NFs reached saturated adsorption at 0.3 mg mL^-1 within 90 min and exhibited significant specific recognition towards the template protein. Moreover, the molecularly imprinted polymers (MIPs) were used to electrochemically detect HRP with good linearity in the range of low concentrations from 0.01 to 0.30 mg mL^-1 through molecular recognition of K₃[Fe(CN)₆] current response. The detection limit of this method was found to be 0.005 mg mL^-1 (S/N = 3). The synthetic strategy paves the way for preparation of functional nanomaterials by molecular imprinting technique and direct detection of proteins in a more convenient, simpler and cheaper way.