Mesoporous Silica for Desorption-Ionization Mass Spectrometry

摘要

Here we demonstrate the use of mesoporous silica thin films for matrix free laser desorption/ionization mass spectrometry (MS). In spite of the growing acceptance of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry for biomolecular analysis, its use in small molecule analysis and tandem MS experiments has been limited. This is chiefly due to interference from matrix molecules and/or issues with uniform energy transfer from matrix to analyte upon UV laser excitation. Further, known matrices are specific for certain molecules, which is an obstacle to rapid analysis of a diverse set of samples. In light of this, recent efforts to develop matrix-free desorption-ionization approaches assume significance. Currently available supports for matrix-free MS include porous silicon and sol-gel-titania films. Mesoporous silica thin films are shown here to be an alternative matrix-free support for mass spectrometry analyses of small molecules ( < 1000 Da). These films are simple to produce, require no special handling or storage, and are stable at ambient laboratory conditions for at least several months. Mass spectra of several low molecular weight molecules desorbed from mesoporous silica without added matrix will be presented.