Magnetic boronate modified molecularly imprinted polymers on magnetite microspheres modified with porous TiO2 (Fe3O4@pTiO2@MIP) with enhanced adsorption capacity for glycoproteins and with wide operational pH range

• Published in: Mikrochimica acta (1966) 2018-12, Vol.185 (12), p.1-10, Article 565
• Main Authors: Sun, Xiao-Yu, Ma, Run-Tian, Chen, Juan, Shi, Yan-Ping
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetonitrile; Adsorption; Affinity; Analytical Chemistry; Aqueous solutions; Binding sites; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Glycoproteins; Imprinted polymers; Iron oxides; Magnetite; Microengineering; Microspheres; Nanochemistry; Nanotechnology; Original Paper; Peroxidase; Silicon dioxide; Titanium dioxide
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-018-3092-z

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 Fe 3 O 4 (magnetite) microspheres coated with porous TiO 2 (Fe 3 O 4 @pTiO 2 @MIP). In contrast to its silica analog (Fe 3 O 4 @SiO 2 @MIP), the flowerlike Fe 3 O 4 @pTiO 2 offers more binding sites for templates. Thus, the adsorption capacity of the Fe 3 O 4 @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 Fe 3 O 4 @pTiO 2 @MIP exhibits higher adsorption for glycoproteins than Fe 3 O 4 @SiO 2 @MIP in both basic and acidic medium. The Fe 3 O 4 @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 0.40–10 μg·mL −1 with the limit of detection of 0.31 μg·mL −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. Graphical abstract Schematic presentation of the magnetic boronate modified molecularly imprinted polymer on magnetic spheres modified with porous TiO 2 (Fe 3 O 4 @pTiO 2 @MIP). It was applied to extract glycoprotein in spiked both basic fetal bovine serum (FBS) and acidic urine samples prior to quantitation by MALDI-TOF mass spectrometry.