Two-dimensional titanate-based zwitterionic hydrophilic sorbent for the selective adsorption of glycoproteins

The selective adsorption towards glycoproteins from complex biosamples is of vital importance in life science studies. A new zwitterionic hydrophilic material, i.e., a functionalized titanate nanosheet, is prepared by assembling well-dispersed gold nanoparticles (AuNPs) on the surface of ultrathin titanate nanosheets via an ion-exchange approach, followed through immobilizing l-cysteine (L-Cys) by Au-S bonding. This 2D-titanate-based zwitterionic hydrophilic material is shortly termed as L-Cys/Au/TiNSs and it exhibits transverse several hundred nanometers with an ultrathin nanosheet structure. The zwitterionic hydrophilic titanate nanosheets have strong adsorption affinity to glycoproteins, offering a large binding capacity towards immunoglobulin G (1098.9 mg g^-1), which could be readily stripped into an ammonium hydroxide (NH₄OH) solution (0.5%, m/v) with a recovery of 82.4%. The practical applications of L-Cys/Au/TiNSs are further proved by successful specific adsorption of IgG from human serum.