Ionization Energy Lowering in Clustered Species Demonstrated by Tunable Photon Energy Laser Desorption Postionization MS

摘要

Molecular clusters form by UV laser desorption of Br_(2)Y films. These clusters - not Br_(2)Y monomers - are the species that undergo 7.87 and 8.0 eV single photon ionization. Neither Br_(2)Y monomers nor clusters desorb in significant amounts from polyelectrolyte multilayers PEMs). Can only detect large components of Br_(2)Y from PEMs by applying CHCA matrix to extract it to the surface for facile matrix assisted desorption. Otherwise, Br~(+) is only the only peak representative of Br_(2)Y. PEMs are designed here as models of bacterial biofilms, which may display similar analyte desorption effects.