Femtosecond pump-probe experiments on trapped flavin: Optical control of dissociation

Femtosecond pump-probe experiments are performed on flavin biomolecules isolated in an ion trap. Mass spectra of the photoinduced fragments show that the fragmentation pathways can be modified using two-color two-photon excitation. In particular, when an infrared probe pulse (810 nm) is added subsequent to the first excitation step (excitation of the S-1 state of flavin mononucleotide at 405 nm), branching ratios between lumichrome and lumiflavin production are inverted relative to the single excitation case.