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Recent Developments in the Chemistry and Chemical Applications of Porous Silicon

“…Energy accumulated from the laser pulse by the matrix is transferred to the incorporated analyte; this exchange induces vaporization and ionization of the dispersed molecules which are then detected and measured by time-of-flight (TOF) mass spectrometry. In contrast to direct desorption/ionization methods from matrix-less surfaces that may yield a plethora of fragmented ion products from a single analyte, MALDI-MS is considered a ''soft'' ablation technique in that the energy transfer is indirect and relatively gentle, substantially reducing the extent of ion degradation and simplifying the interpretation of the mass spectra [121][122][123][124][125][126]. Furthermore, its sensitivity to femtomolar and attomolar levels of analytes and its tolerance for mixtures and biological contaminants afford the characterization of minimal sample sizes of only modest purity.…”

Multiple photon excitation of adsorbed toluene by KrF laser

“…The laser-modified surface influenced both the laser field acting on the adsorbed molecules and the dynamics of their excitation. Our previous study dealt with adsorbed halomethanes irradiated with excimer lasers [13][14][15]. We found that the three-photon dissociation of halomethanes prevailed over the one-photon process at laser intensities higher than 1 MW cm −2 if the first photon excited a repulsive state.…”