Abstract
An effi cient method to prepare surface-assisted laser desorption ionization (SALDI) substrates which are
used for mass spectrometry of biomolecules has been developed. Gold nanoparticles used as the matrix
of SALDI substrate are prepared by laser ablation in liquids. To deposit the colloidal nanoparticles,
electrophoresis, instead of dropping the colloidal solution onto a substrate reported in the previous study,
is used, because the colloidal nanoparticles prepared by laser ablation in liquids are electronically
charged. It is demonstrated that the thickness and the surface morphology of SALDI substrates are
conveniently controlled by adjusting the concentration of colloids. The SALDI effi ciency for substrates
prepared from colloids with higher concentrations was higher. The infl uence of the thickness and the
surface morphology on the SALDI effi ciency was discussed.
