Synthesis of surface molecularly imprinted nanoparticles for recognition of lysozyme using a metal coordination monomer

• Using a metal coodination monomer for constructing surface protein-imprinted nanoparticles.
• Effectively optimizing the imprinting performance by tuning the feed crosslinking degrees.
• The imprinted particles showing not only high binding capacity, selectivity and rapid kinetics, but also high binding affinity.

Molecularly imprinted polymers against proteins are regarded as promising substitutes for natural antibodies, but have been frustrated with the problems including reduced interaction between functional monomers and protein template in the aqueous media required during their synthesis and restricted mass transfer across the resulting crosslinked polymer matrixes. For addressing these issues, herein we proposed a strategy for imprinting of a protein on the surface of nanoparticles using a metal chelating monomer. With lysozyme as a model protein template and Cu2+ chelating N-(4-vinyl)-benzyl iminodiacetic acid as the coordination monomer along with other monomers, protein imprinted polymer nanoshells were formed over vinyl-modified silica nanoparticles via surface polymerization in high-dilution monomer solution. The feed concentration of the crosslinking monomer was optimized toward achieving the best imprinting effect. Compared with the related imprinted materials reported previously, the resultant core–shell imprinted particles showed greatly faster binding kinetics, elevated rebinding capacity and selectivity. More importantly, noticeably high binding affinity was achieved with an estimated dissociation constant of 4.1×10−8 M which is comparable to that of conventional antibodies