N-terminal epitope surface imprinted particles for high selective cytochrome c recognition prepared by reversible addition- fragmentation chain transfer strategy

A kind of surface imprinted particles was synthesized to recognize cytochrome c (Cyt c) by a novel strategy combining reversible addition-fragmentation chain transfer (RAFT) radical polymerization and epitope surface imprinting. N-terminal epitope nonapeptide of Cyt c was chosen as the template. The selectivity of these particles for protein recognition was obviously improved due to the selection of epitopes rather than the whole protein as templates and the controllable length of polymer shell chain. After epitope had been modified on the surface of silica, the surface imprinted polymer with controlled imprinted layer was synthesized with monomers and cross-linkers by RAFT radical polymerization strategy. The epitope surface imprinted particles were obtained after the peptide removed and trithioester group destruction by hexylamine. The binding capacity of N-terminal peptide reached 1.88 mg peptide per gram with imprinting factor (IF) as 2.42 while the binding capacity of Cyt c reached 8.89 mg protein per gram with IF as 1.71, which were obviously higher than the IF of the material without RAFT strategy. Moreover, Cyt c could be selectively recognized by the epitope surface imprinted particles even in presence of the competitive proteins with different molecular weight and isoelectric point. The performance of protein recognition remained 90% after five cycles of adsorption and desorption. All these results demonstrated that the epitope surface imprinted particles prepared by RAFT strategy are promising to achieve the protein recognition with higher recognition ability, selectivity and reusability.