Carbon nanostructure morphology templates nanocomposites for phosphoproteomics

Protein and peptide phosphorylation regulate numerous pathological processes, however, their characterization is challenging due to their low abundance and transient nature. Therefore, nanomaterials are being developed to address this demanding task. In particular, carbon nanostructures are attracting interest as scaffolds for functional nanocomposites, yet only isolated studies exist on the topic, and little is known on the effect of nanocarbon morphology on templating nanocomposites. In this work, we compared oxidized carbon nanotubes, graphene oxide, oxidized carbon nanohorns and oxidized graphitized carbon black, as scaffolds for magnetized nanocomposites. The nanomaterials were extensively characterized with experimental and in silico techniques. Next, they were applied to phosphopeptide enrichment from cancer cell lysates for NanoHPLC-MS/MS, with selectivity as high as nearly 90% and several-thousand identification hits. Overall, new insights emerged for the understanding and the design of nanocomposites for phosphoproteomics.