Metal-phenolic networks modified two-dimensional magnetic MXene-based composites for highly efficient enrichment of phosphopeptides

Efficient and specific enrichment of phosphopeptides is a precondition for the research of phosphoproteomics-related processes, while the development of more superior affinity materials remains a long-term challenge. In this work, Zr-tannic acid metal-phenolic networks (MPNs) modified magnetic composites based on two-dimensional MXene substrates, denoted as Ti3C2Tx@Fe3O4@MPNs-TA/ZrIV, were facilely prepared and inno-vatively applied for phosphopeptides enrichment. By virtue of large specific surface, excellent magnetic responsiveness, and massive affinity sites provided by TA/ZrIV-based MPNs, the Ti3C2Tx@Fe3O4@MPNs-TA/ZrIV composites exhibited outstanding enrichment performance with high sensitivity (1 fmol & mu;L-1), excellent selec-tivity (& beta;-casein: bovine serum albumin = 1:5000, molar ratio), and satisfactory repeatability (5 times). Encouraged by the remarkable enrichment results, we further employed the Ti3C2Tx@Fe3O4@MPNs-TA/ZrIV composites to detect phosphopeptides from non-fat milk and human saliva, which confirmed the great potential of Ti3C2Tx@Fe3O4@MPNs-TA/ZrIV composites in phosphopeptide enrichment from intricate biological speci-mens. The enrichment results demonstrate that Ti3C2Tx@Fe3O4@MPNs-TA/ZrIV composites are ideal candidates for the research of phosphoproteomics and also promote the application of surface-functionalized MXene-based materials in the biomedical field.