Nanostructured silicon substrate for desorption/ionization on silicon mass spectrometry coupled with titanium oxide and zinc oxide coated magnetic nanoparticles for phosphopeptide analysis

The use of a nanostructured silicon (nSi) substrate for desorption/ionization on silicon mass spectrometry (DIOS-MS) integrated with functionalized iron oxide magnetic nanoparticles (MNPs) for phosphopeptide mass spectrometry (MS) analysis was demonstrated for the first time. The results indicate that the use of titanium oxide (TiO₂) and zinc oxide (ZnO) coated MNPs coupled with the nSi-MS technique (MNPs/nSi-MS) is a high-performance method for phosphopeptide analysis in which the nSi serves as a matrix-free DIOS-MS target substrate with high MS detection sensitivity and the MNPs selectively capture the phosphopeptide for enhanced MS detection selectivity.