The complexes of C-reactive protein (CRP) with its polymerizable phosphocholine ligands adsorbed at the styrene–water interface were polymerized. The molecularly imprinted polymer (MIP) exhibited a binding affinity for CRP comparable to that of immobilized anti-CRP antibody. The determination of human serum CRP using the MIP-based sandwich immunoassay has been demonstrated.

In the present study, we describe the easy isolation of C-reactive protein (CRP) from human serum using phosphocholine-modified magnetic nanoparticles (MNPs). A phosphocholine-based monomer, 3-(4)-vinylbenzyl-12-phosphorylcholine dodecanoate (VPC), was polymerized on methacrylate-coated MNPs and the resulting MNPs (VPC-MNPs) were assessed for their ability to isolate CRP from a human serum sample. CRP could be isolated from human serum with one adsorption step to VPC-MNPs within 1 h. The high purity of the isolated CRP fraction determined by SDS-PAGE indicates a good selectivity of VPC-MNPs for CRP binding. These results demonstrate the feasibility of using ligand-functionalized MNPs for rapid, easy, and efficient protein isolation.