Magnetic-graphene oxide based molecular imprinted polymers for selective extraction of glycoprotein at physiological pH

Abstract

Glycoproteins are extensively used as biomarkers in clinical diagnosis. Therefore, it is a critical requirement to develop efficient methods for ultrasensitive detection and extraction of glycoprotein from physiological fluids. In this paper, by combination of surface imprinting, phenylboronic affinity, and magnetic graphene oxide, a novel type of magnetic molecularly imprinted polymers (MGO/MIPs) was prepared for selective extraction of glycoprotein at physiological pH. During the preparation process, 2,4-difluoro-3-formyl phenylboronic acid – modified magnetic graphene oxide (MGO/DFFPBA) were used as supporting matrices for glycoprotein (horseradish peroxidase, HRP) immobilization, and acrylamide (AAm) was chosen as functional monomer. The polymerization conditions and binding properties of MGO/MIPs were investigated. The results indicated that MGO/MIPs exhibited outstanding binding capacity (200.88 mg/g calculated by Langmuir isotherm equation), fast capture kinetics (35 min), and favorable regeneration ability toward HRP. More importantly, benefitting from low pKa value of DFFPBA, the binding experiment was carried out under physiological pH. Successful extraction of HRP from human serum samples further confirmed the practical utility of the obtained material. Besides, the obtained material could be separated easily by a magnet. All those features make MGO/MIPs promising in separation of glycoprotein from complex samples.