Thiol-yne click synthesis of boronic acid functionalized silica nanoparticle-graphene oxide composites for highly selective enrichment of glycoproteins

In this work, a facile novel strategy is developed for the preparation of 4-mercapto-phenylboronic acid functionalized silica nanoparticle-graphene oxide composite (GO@MPBA) via thiol-yne click reaction. The morphology, structure and composition of the resulting GO@MPBA was characterized by transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy, Thermogravimetric analysis and X-ray photoelectron spectrometry. GO@MPBA exhibited the high binding capacity towards glycoproteins such as ovalbumin (1288.8 mg g(-1)), immunoglobulin G (1144.1 mg g(-1)), transferrin (592.1 mg g(-1)) and horseradish peroxidase (392.4 mg g(-1)), in contrast, the binding capacity of each non-glycoproteins (cytochrome c, deoxyribonuclease A, pepsin, trypsin, lysozyme and bovine serum albumin) is less than 50 mg g-1. Furthermore, the GO@MPBA still remained a good binding capacity after the five times of adsorption-desorption cycles. The selective enrichment of glycoproteins from real egg white samples by GO@MPBA was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. This work could present a facile novel approach of surface modification to design environmentally friendly and more efficient adsorbents for the isolation and enrichment of glycoprotein from complex biological samples. (C) 2017 Elsevier B.V. All rights reserved