On the synthesis and rebinding properties of [Co(C 2H 3O 2) 2(z-Histidine)] imprinted polymers prepared by precipitation polymerization

In the present study, the synthesis via free-radical precipitation polymerization of metal-complexing polymer microparticles capable of specific binding to [Co(C 2H 3O 2) 2(z-Histidine)] complex is reported. Initially, the functional monomer (i.e., 4-vinylpyridine, a vinyl monomer with metal chelate properties) is complexed together with the template [Co(C 2H 3O 2) 2(z-Histidine)] molecule via the mediation of cobalt ions. Evidence of the polymerizable complex formation is obtained through the compleximetric titration of the z-Histidine in the prepolymerization reaction mixture. Subsequent polymerization of the polymerizable complex with a bi-functional or tri-functional cross-linker results in the formation of imprinted polymer microparticles in the size range of 1–5 µm. The effects of agitation, cross-linker type, degree of cross-linking and molar ratio of the template to the functional monomer on the rebinding properties of the imprinted polymers are experimentally assessed. The synthesized imprinted polymers can potentially find application in the purification of his-tagged recombinant proteins.