Chemically modified chitosan beads as matrices for adsorptive separation of proteins by molecularly imprinted polymer

A simple molecularly imprinted polymer (MIP) was prepared using hemoglobin as the imprinted molecule and acrylamide as the functional monomer. The MIP was achieved by grafting of the selective soft polyacrylamide gel to the maleic anhydride modified chitosan beads by letting the monomers and the protein diffuse into the pores of the chemically modified chitosan matrix before starting the polymerization. The chitosan beads were freed from the surrounding polyacrylamide gel by washing. Langmuir analysis showed that an equal class of adsorption was formed in the MIP, the adsorption equilibrium constant and the maximum adsorption capacity were evaluated to be 1.47 and 35.7 mg/g wet MIP beads, respectively. The MIP has much higher adsorption capacity for hemoglobin than the non-imprinted polymer with the same chemical composition, and also has a higher selectivity for the imprinted molecule. The MIP can be reused and the reproducibility was approximately 100% at low concentration. (c) 2005 Elsevier Ltd. All rights reserved.