Biofunctionalization of silica microspheres for protein separation

► SiO2-SH microspheres were prepared in water using one-pot synthesis. ► The content of surface SH was investigated by Ellman method and XPS spectra. ► The ratio of SH to mass strongly depends on the reaction conditions. ► SiO2-SH microspheres were biofunctionalized by glutathione. ► SiO2-GSH can be used to capture selectively Glutathione S-transferase.