Surfactant Enhanced Mass Spectrometry for Desorption/Ionization on Silicon Mass Spectrometry (DIOS-MS)

Laser Energy: 1.4 µ J The successful application of MALDI to analyze a wide variety of molecules lies in its ability to generate intact ions of thermally labile molecules using a UV absorb- ing matrix. One of the properties of a good MALDI matrix is its ability to absorb at the wavelength of the laser used. The perfluorinated surfactant, PFOS, investi- gated in this study did not display any UV absorbance at 337 nm. As a result, no signal was obtained in the analysis of 250 fmol α -casein digest mixed with PFOS on a MALDI plate. In contrast, peptide mass map obtained from the same sample on perfluoroalkyl functionalized pSi surface demonstrates the surfactants' utility with DIOS-MS. Asterisks on the spectra indicate peptides identified by Mascot.