Magnetic boronate modified molecularly imprinted polymers on magnetite microspheres modified with porous TiO2 (Fe3O4@pTiO(2)@MIP) with enhanced adsorption capacity for glycoproteins and with wide operational pH range

摘要

Boronate-affinity based molecularly imprinted polymers (MIPs) are beset by the unsatisfied adsorption capacity and narrow working pH ranges. A magnetic molecularly imprinted polymer containing phenylboronic acid groups was placed on the surface of Fe3O4 (magnetite) microspheres coated with porous TiO2 (Fe3O4@pTiO(2)@MIP). In contrast to its silica analog (Fe3O4@SiO2@MIP), the flowerlike Fe3O4@pTiO(2) offers more binding sites for templates. Thus, the adsorption capacity of the Fe3O4@pTiO(2)@MIP is strongly enhanced. The strong electron-withdrawing effects of Ti(IV) enable the boronic acid of the MIP to have better affinity for glycoproteins at a wide pH range from 6.0 to 9.0. Consequently, the Fe3O4@pTiO(2)@MIP exhibits higher adsorption for glycoproteins than Fe3O4@SiO2@MIP in both basic and acidic medium. The Fe3O4@pTiO(2)@MIPs were eluted with 5% acetic acid aqueous solution containing 30% acetonitrile, and the eluate was analyzed by MALDI-TOF MS. The method was applied to the selective extraction and quantitation of horseradish peroxidase (HRP) in spiked fetal bovine serum (FBS). The linear range is 0.40-10gmL(-1) with the limit of detection of 0.31gmL(-1). In our perception, this work has a wide scope in that is paves the way to a more widespread application of boronate affinity based MIPs for analysis of glycoproteins and related glyco compounds even at moderately acidic pH values.