Amino acid side chain-like surface modification on magnetic nanoparticles for highly efficient separation of mixed proteins

► Various surface modifications were introduced for mixed proteins separation. ► Systematic characterization was achieved by solid-state NMR, BET, FT-IR, and XPS. ► Protein separation efficiency was calculated at each pH. ► Adsorption of mixed proteins onto Si-MNPs@SH was governed not by pH but by Mw.