Phosphopeptide enrichment with inorganic nanofibers prepared by forcespinning technology

• Titanium and zirconium dioxide nanofibers have been tested for phosphopeptide enrichment followed by mass spectrometry detection.
• The columns packed with the nanofibers have shown significantly higher permeability and binding capacity in comparison to the particulate sorbent packed column.
• Efficient and selective enrichment of phosphopeptides from tryptic digests has been obtained.

Efficient selective sample enrichment is often a key procedure in protocols for analyses of complex samples. This applies not only to trace sample components but also to species with weak detection response. For example enrichment of phosphopeptides using selective affinity techniques prior to mass spectrometry analysis is necessary to increase detection sensitivity of phosphopeptides from highly complex peptide mixtures. In this work we have developed inorganic nanofibrous materials based on titanium or zirconium dioxides for selective and efficient enrichment of phosphopeptides for MALDI/MS detection. In comparison to the common bead based materials the presented nanofibrous materials exhibit much higher permeability allowing their use not only for batch mode or packed in the column operation, but also in the pipette tip format without the need for high pressure. Both the methods of preparation and characterization of the resulting materials are presented.