Magnetic metal-organic frameworks containing abundant carboxylic groups for highly effective enrichment of glycopeptides in breast cancer serum.

A mercaptosuccinic acid functionalized hydrophilic magnetic metal-organic framework nanocomposite (denoted as mMOF@Au-MSA) was proposed and synthesized to provide an excellent platform for glycopeptide analysis. The novel nanomaterial integrated favorable advantages such as robust magnetic response from Fe3O4 magnetic nanoparticles, large surface area contributed by MOF, abundant ultra-high hydrophilic carboxylic groups from mercaptosuccinic acid, as well as unbiased affinity toward different types of glycopeptides. This nanocomposite was successfully utilized to capture glycopeptides from standard protein digests with the high selectivity and great sensitivity of 0.5 fmol μL-1. Notably, 307 glycopeptides assigned to 96 glycoproteins were identified from only 2 μL serum of breast cancer patient. The satisfying achievement indicated that the as-prepared nanopartical had promising potential in exploring the knowledge of glycoproteins in breast cancer.