Effect of biomolecule chemical structure on the synthesis of surface magnetic molecularly imprinted polymer in aqueous solution using various monomers for high-capacity selective recognition of human insulin

摘要

Magnetic molecular imprinting technique was used for the detection of human insulin. The structure and binding sites of insulin determined by the use of Cn3D software were considered in the selection of functional monomers types and ratios. Methacrylic acid (MAA) was chosen as the electrostatic functional monomer and acrylamide (AAm) as the neutral monomer with a cross-linker of methylenebisacrylamide (MBAAm) for surface imprinting onto vinyl-functionalized Fe3O4 nanoparticles (MNPs). The effect of factors including the monomers' molar ratio, pH of the synthesis media, template concentration, type of eluent solution, and elution time was investigated on the characteristics and performance of molecularly imprinted polymers along with the molecular analysis of the system at the elution stage. The results revealed the importance of considering the template structure. The best result was obtained with an imprinting factor equal to 2.2 by magnetic molecularly imprinted polymers at the molar ratio of 20:100:5 for MAA:AAm:MBAAm (on the basis of 1 M of insulin), synthesized in phosphate buffer (pH = 6) and eluted with methanol/acetic acid (9/1, v/v) solution for 72 h. Its high selective recognition to insulin in the presence of a competitor demonstrated the separation ability of the imprinted polymer to the template molecule.