Designed synthesis of Graphene @titania @mesoporous silica hybrid material as size-exclusive metal oxide affinity chromatography platform for selective enrichment of endogenous phosphopeptides

• A G @TiO2 @mSiO2 material was synthesized to enrich endogenous phosphopeptides.
• The method has a relative low detection limit.
• The endogenous phosphopeptides can be selectively enriched from bio-samples.

In this work, a novel size-exclusive metal oxide affinity chromatography (SE-MOAC) platform was built for phosphoproteome research. The operation for preparing graphene @titania @mesoporous silica nanohybrids (denoted as G@TiO2@mSiO2) was facile and easy to conduct by grafting titania nanoparticles on polydopamine (PD)-covered graphene, following a layer of mesoporous silica was coated on the outermost layer. The G@TiO2@mSiO2 nanohybrids exhibited high sensitivity with a low detection limit of 5 amol/μL (a total amount of 1 fmol) and high selectivity for phosphopeptides at a mass ratio of phosphopeptides to non-phosphopeptides (1:1000). The size-exclusive capability of the nanohybrids were also demonstrated by enriching the phosphopeptides from the mixture of Bovine Serum Albumin (BSA), α-casein, and β-casein digests with a high mass ratio (β-casein digests: α-casein: BSA, 1:500:500), which was attributed to the large surface area and ordered mesoporous channels. In addition, the G@TiO2@mSiO2 nanohybrids were employed to capture the endogenous phosphopeptides from human serum successfully.

The graphene @titania @mesoporous silica nanohybrids (G@TiO2@mSiO2) were synthesized which could enrich endogenous phosphopeptides form complex bio-samples efficiently.Figure optionsDownload as PowerPoint slide