PEGylated titanate nanosheets: hydrophilic monolayers with a superior capacity for the selective isolation of immunoglobulin G

A novel organic–inorganic hybrid was prepared by anchoring (3-aminopropyl)triethoxysilane (APTES) on the surface of monolayer titanate nanosheets and subsequent modification with hydrophilic polyethylene glycol (PEG). The PEGylated hydrophilic monolayer titanate nanosheets were abbreviated as PEG–APTES–TiNSs, and they exhibit a lateral dimension of dozens of nanometers and a thickness of ca. 1.9 nm. PEGylation of the titanate nanosheets significantly improved their selectivity toward the adsorption of glycoproteins through strong hydrophilic interaction, providing an adsorption capacity of 2540.9 mg g−1 for immunoglobulin G (IgG). The retained IgG is readily collected at a recovery rate of 83.4% with 0.5% (m/v) ammonium hydroxide (NH4OH) as the stripping reagent. PEG–APTES–TiNSs are applied for the selective adsorption of IgG from human serum, which is further confirmed by SDS-PAGE assay.