Enrichment of serum biomarkers by magnetic metal-organic framework composites

Highly efficient extraction of peptides from serum is critical for finding serum biomarkers using mass spectrometry, which still remains a great challenge. Currently, a bottom-up proteomics approach has been applied to discover serum biomarkers. However, the approach was labor intensive, time and cost consuming, and cannot meet the requirements for clinical application. In this work, Fe3O4/C@MIL-100 composites were synthesized to efficiently capture peptides from microwave-assisted formic acid digests of BSA and human serum prior to MALDI-TOF MS analysis. Fe3O4/C@MIL-100 composites exhibited size-selective adsorption performance, thus providing a rapid and convenient approach to enrich low-abundance peptides. Notably, the peptides' mass fingerprinting of serum digestions between type 2 diabetes mellitus (T2DM) and healthy persons were distinguishable, which indicated the potential ability of this technique for T2DM diagnosis and rapid biomarker discovery.