S. Mouradian et al., A SELF-ASSEMBLED MATRIX MONOLAYER FOR UV-MALDI MASS-SPECTROMETRY, Journal of the American Chemical Society, 118(36), 1996, pp. 8639-8645
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry
has in recent years significantly advanced the field of polymer analys
is. However, the mechanisms of the desorption and ionization processes
, and in particular the critical role played by the matrix, remain unc
lear. In the present work, the usual matrix is replaced with a self-as
sembled monolayer consisting of a UV absorbing matrix-like compound co
valently linked to a gold surface. Analytes such as proteins or oligon
ucleotides are directly deposited on the covalently modified probe tip
s and mass analyzed by laser desorption time of flight (TOF) mass spec
trometry. Several types of monolayers were investigated and tested for
their ability to produce positive and negative analyte ions. Molecula
r ion signals were obtained for dT(10) oligonucleotides and proteins a
s large as cytochrome C on monolayers of methyl N-(4-mercaptophenyl)ca
rbamate (MMPC). The amenability of this model system to characterizati
on with established physical and chemical methods should help investig
ate the processes involved in MALDI.