Synthesis of boronic acid-functionalized molecularly imprinted silica nanoparticles for glycoprotein recognition and enrichment

A novel imprinting strategy using reversible covalent complexation of glycoprotein is described for creating glycoprotein-specific recognition cavities on 3-acrylamidophenylboronic acid-immobilized silica nanoparticles (SiO2@AAPBA). Two kinds of organic silanes (3-aminopropyltriethoxysilane (APTES) and n-octyltrimethoxysilane (OTMS)) were then polymerized on the surface of SiO2@AAPBA after the template (horseradish peroxidase (HRP)) was covalently immobilized by forming cyclic boronate complexes and their influence was examined. The results showed that not only the silane composition but also the relative proportions play an important role in glycoprotein imprinting. The template recognition properties were evaluated by single-protein or competitive batch rebinding experiments, and the results showed that the HRP-imprinted silica nanoparticles (HRP-MIP silica NPs) exhibited higher recognition ability and selectivity towards the template than the nonimprinted silica NPs and their corresponding imprinted factor (a) reached 2.71. The as-prepared HRP-MIP silica NPs could not only differentiate the template from another glycoprotein, but also enrich HRP from spiked human serum. The good results demonstrated their potential in glycoproteomic analysis.