Synthesis and applications of epoxy-functionalized bi-functional magnetic molecularly imprinted polymers for polysaccharide adsorption

Abstract

A polysaccharide-imprinted nanoparticle composite material with bi-functional monomers molecularly imprinted polymers (Bi-MMIPs) was successfully synthesized in aqueous solution by using starch as the template, 3-aminobenzeneboronic acid (APBA) as the functional monomer, 2-acrylamide-2-methylpropanesulfonic acid (AMPS) as the co-functional monomer, and ammonium persulfate (APS) as the initiator. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared (FT-IR) spectroscopy were used to characterized Bi-MMIPs. The adsorption and recognition characteristics of Bi-MMIPs for starch were investigated in detail by using the static method, dynamic method, and competitive adsorption experiments. The TEM, SEM and FT-IR results showed that the two functional monomers were loaded on the surface of Bi-MMIPs. Bi-MMIPs possessed very strong adsorption affinity and specific recognition for starch. The saturated adsorption capacity reached 13.88 mg/g, and the selectivity coefficients relative to glucosans Mr 5000 Da and 70000 Da were 2.67 and 3.77, respectively. Despite the imprinting factor of Bi-MMIPs (α=3.04), Bi-MMIPs were regenerated easily and exhibited excellent recognition, selectivity, and reusability for adsorbing starch. To elucidate the mechanism, APBA and AMPS showed synergy effect in synthesizing bi-functional monomers by providing reversible covalent bonds and hydrogen bonds, respectively, which could effectively enhance the spatial arrangement of combining sites for template molecular.