A hydrophilic two-dimensional titanium-based metal-organic framework nanosheets for specific enrichment of glycopeptides

A hydrophilic two-dimensional titanium-based metal-organic framework (MOF) nanosheets were prepared and applied to improve the glycopeptides enrichment efficiency. Seventeen N-linked glycopeptides from horseradish peroxidase (HRP) tryptic digests were readily identified and the results showed highly improved signal intensities. As the molar ratio of the mixture of tryptic digests of HRP, glycoprotein (HRP), and nonglycoprotein (BSA) reached 1:800:800, good selectivity of the Ti-MOF nanosheets were still clearly observed. As to human serum samples, 41 glycoproteins and 66 glycopeptides corresponding to 68 N-glycosylation sites were finally detected, which showed the good ability of the nanosheets material to enrich N-linked glycopeptides from complex human serum samples. Moreover, the Ti-MOF nanosheets exhibited unique stability and reusability even after being regenerated and reused for five times. It also performed a high sensitivity (1 × 10−10 M HRP), a good enrichment capacity (250 mg/g) for glycopeptides enrichment and a high enrichment recovery of 78%, suggesting a great application prospect for the enrichment of N-linked glycopeptides and the analysis glycoproteomic research.