Affinity surface-assisted laser desorption/ionization mass spectrometry for peptide enrichment

摘要

In this paper, we report on the functionalization of silicon nanostructured(NanoSi)surface with an organic layer of nitrilotriacetic acid(NTA)and its subsequent use as an affinity surface-assisted laser desorption/ionization mass spectrometry(SALDI-MS)interface for histidine-tagged peptide enrichment and mass spectrometry analysis. The NTA terminal groups are immobilized onto the NanoSi surface via very stable Si-C covalent bonds. The NTA-modified NanoSi(NTA-NanoSi)interface was characterized by contact angle measurements, Fourier transform infrared(FTIR)spectroscopy and X-ray photoelectron spectroscopy(XPS). The NTA-NanoSi interface has shown a good selectivity toward His-tagged peptide and permits its enrichment from an artificial mixture of both tagged and untagged peptides and its subsequent mass spectrometry detection with good signaloise ratio.