Magnetic mesoporous silica nanoparticles modified by phosphonate functionalized ionic liquid for selective enrichment of phosphopeptides

In this study, new magnetic nanoparticles (denotated as Fe3O4@mSiO2-PFIL-Ti4+) have been prepared by immobilizing titanium ions with phosphonate functionalized ionic liquid (PFIL) on the wall of core-shell structured mesoporous nanomaterials. The resulting nanoparticles possess large specific surface area, strong hydrophilicity and fast magnetic response. The composites can capture traces of phosphopeptides from the tryptic β-casein digest (0.08 fmol), a digest mixture of β-casein and BSA (1 : 10 000, molar ratio) as well as a blend of β-casein digest and a great quantity of phosphorylated protein (β-casein) and non-phosphorylated protein (BSA) (1 : 2000 : 2000, mass ratio), respectively, showing excellent sensitivity, selectivity and size exclusion ability. Additionally, Fe3O4@mSiO2-PFIL-Ti4+ shows excellent steadiness and can be reused at least 12 times. Moreover, this material was successfully applied to enrich endogenous phosphopeptides from complex bio-samples, including human saliva and serum.

Specific enrichment combined with highly efficient solid-phase tagging for the sensitive detection of heparin based on boronic acid-functionalized mesoporous silica nanospheres

A combined specific enrichment and highly efficient solid-phase tagging approach is presented for heparin detection using boronic acid-functionalized mesoporous silica nanospheres as extraction sorbents and nanoscale reactors. It exhibits a faster reaction time (only 6 min), higher tagging-product purity and lower applicable sample concentration compared with liquid-phase tagging.

A cool and high salt-tolerant ionic liquid matrix for preferential ionization of phosphopeptides by negative ion MALDI-MS

An optimized ILM G₃THAP/PA matrix significantly improved the detection of phosphopeptides by negative ion MALDI-MS compared with using 3-AQ/CHCA/ADP and DHB/PA matrices.