Highly efficient enrichment of phosphopeptides by a magnetic lanthanide metal-organic framework

Highly efficient enrichment of phosphopeptides from complex biological samples is crucial prior to mass spectrometry analysis due to the low abundance and ion suppression effects. In this study, a facile route was designed for preparation of a magnetic erbium(Er)-based metal-organic framework (denoted as Fe3O4@PDA@Er(btc)), which was synthesized with 1,3,5-benzenetricarboxylic acid(H(3)btc) as ligand and grafted on the polydopamine (PDA) - coated Fe3O4. The as-prepared material exhibited ultra-high sensitivity (detection limit of 20 amol/mu L) and selectivity at a low mass ratio of beta-Casein/BSA (1:500). Moreover, it was also investigated for enrichment of phosphopeptides from human serum, which provided a promising technique for highly efficient enrichment of low-abundance phosphorylated peptides in the practical application. (C) 2016 Elsevier B.V. All rights reserved.