Preparation of sandwich‐structured graphene/mesoporous silica composites with C8‐modified pore wall for highly efficient selective enrichment of endogenous peptides for mass spectrometry analysis

In this study, sandwich‐structured graphene/mesoporous silica composites (C8‐modified graphene@mSiO2) were synthesized by coating mesoporous silica onto hydrophilic graphene nanosheets through a surfactant‐mediated cocondensation sol‐gel process. The newly prepared C8‐modified graphene@mSiO2 nanocomposites possess unique properties of extended plate‐like morphology, good water dispersibility, highly open pore structure, uniform pore size (2.8 nm), high surface area (632 m2/g), and C8‐modified‐interior pore walls. The unique structure of the C8‐modified graphene@mSiO2 composite nanosheets not only provide extended planes with hydrophilic surface that prevents aggregation in solution, but also offer a huge number of C8‐modified mesopores with high surface area that can ensure an efficient adsorption of peptides through hydrophobic–hydrophobic interaction between C8‐moified pore walls and target molecules. The obtained C8‐modified graphene@mSiO2 materials were utilized for size selectively and specifically enriching peptides in standard peptide mixtures and endogenous peptides in real biological samples (mouse brain tissue).