Comparing pulsed and continuous laser-induced acoustic desorption (LIAD) as sources for intact biomolecules

Abstract A major obstacle to the gas-phase study of larger (bio)molecular systems is vaporisation step, that is, introduction intact sample molecules into gas-phase. promising approach use laser-induced acoustic desorption (LIAD) sources, which have been demonstrated using both nanosecond pulsed and continuous lasers. We directly compare here approaches for first time under otherwise identical conditions adenine as a prototypical biological molecule, produced molecular plumes femtosecond multiphoton ionisation. observe different mechanisms at play two laser sources; however, we find no evidence in either case process leads fragmentation target molecule unless excessive energy applied. This makes LIAD powerful techniques require high density purity samples gas-phase, such ultrafast dynamics studies or diffraction experiments. Graphic abstract