The Au−TiO2 Janus Material Enables Integration of Serum Exosome Capture with Palmitoylated and Phosphorylated Peptide Enrichment for Non-Small Cell Lung Cancer Profiling

Abstract An Au−TiO2 Janus material was designed to integrate exosome capture with dual post-translational modification (PTM) enrichment (palmitoylation and phosphorylation). The Au domain selectively enriched palmitoylated peptides through Au−S covalent interactions, while the TiO2 domain exhibited dual functions: enriching phosphorylated peptides through metal oxide affinity chromatography and capturing serum exosomes through specific interactions with phosphate groups on the exosomal lipid bilayers. Coupled with mass spectrometry, the Au−TiO2 Janus material exhibited excellent selectivity and sensitivity for palmitoylated and phosphorylated peptides. When this strategy was applied to serum samples from patients with non-small-cell lung cancer (NSCLC) and normal controls, four differentially expressed dual-PTM proteins (SERPINA1, CFH, AHSG, and IGLL1) were identified, all of which are associated with inflammation and immune abnormalities in the tumor microenvironment of NSCLC. The developed strategy represents an integrated workflow that enables simultaneous profiling of exosomal palmitoylation and phosphorylation, providing insights into biomarker discovery in NSCLC.