Bovine serum albumin-imprinted polymer gels prepared by graft copolymerization of acrylamide on chitosan

A graft copolymerization of acrylamide with N,N′-methylenebisacrylamide on chitosan in aqueous medium was utilized in the synthesis of molecularly imprinted polymer (MIP) gels using bovine serum albumin (BSA) as a template. The effect of the amount of initiator and the molecular weight and amount of chitosan on BSA rebinding was investigated. It was found that the resultant MIP gels based on chitosan-g-polyacrylamide (CS-g-PAM) showed significantly higher imprinting efficiency than those only consisting of polyacrylamide (PAM), and also better than those composed of chitosan/PAM semi-interpenetrating polymer network (CS/PAM-s-IPN). The batchwise adsorption of BSA and some non-template proteins showed that the CS-g-PAM based MIP gels demonstrated a quite significant template binding capacity different from the non-imprinted polymer (NIP) gels, and an obvious binding specificity for BSA. The adsorption isotherms of BSA on the MIP gels were determined and well fitted by a Langmuir model with a maximum binding capacity of 39.49 mg/g wet gels. The adsorption kinetics was analyzed by a linear driving force mass-transfer model. The MIP gels also showed much better stability in rebinding of the imprint molecules than those based on CS/PAM-s-IPN after three adsorption–regeneration cycles.