Three-Dimensional MAX-Ti 3 AlC 2 Nanomaterials for Dual-Selective and Highly Efficient Enrichment of Phosphorylated and Glycosylated Peptides.

Dual-selective enrichment of phosphopeptides and glycopeptides of post-translational modifications (PTMs) in the complex biological samples are challenging. In this work, considering the versatile properties including surface abundant metal sites and electrostatic attraction between Ti 3 C 2 -layers and Al-layers, layered ternary carbides Ti 3 AlC 2 nanomaterials was successfully applied for the first time as an affinity adsorbent for the dual-selective capture of phosphopeptides and glycopeptides. Especially, the Ti 3 AlC 2 nanomaterials had an excellent detection sensitivity for phosphopeptides (1×10 -11  M) and a good selectivity for glycopeptides with a low molar ratio of 1 : 500 of HRP (horseradish peroxidase) to BSA (bovine serum albumin). Furthermore, Ti 3 AlC 2 nanomaterials was also applied for dual-selective enrichment of phosphopeptides and glycopeptides from mouse brain neocortex lysate and human serum lysate respectively before mass spectrometry (MS) analysis, yielding twenty-two unique phosphopeptides from thirteen phosphoproteins and fifty-three unique glycopeptides from thirty-seven glycoproteins, respectively. This work will open a new avenue and will greatly promote sample preparation for mass spectrometric analysis in phosphoproteomics and glycoproteomics research.