Multiphoton-excited serotonin photochemistry.
We report photochemical and photophysical studies of a multiphoton-excited reaction of serotonin that previously has been shown to generate a photoproduct capable of emitting broadly in the visible spectral region. The current studies demonstrate that absorption of near-infrared light by an intermediate state prepared via three-photon absorption enhances the photoproduct formation yield, with the largest action cross sections ( approximately 10(-19) cm(2)) observed at the short-wavelength limit of the titanium:sapphire excitation source. The intermediate state is shown to persist for at least tens of nanoseconds and likely to be different from a previously reported oxygen-sensitive intermediate. In addition, the two-photon fluorescence action spectrum for the fluorescent photoproduct was determined and found to have a maximum at approximately 780 nm (3.2 eV). A general mechanism for this photochemical process is proposed.
Gostkowski
Michael L
ML
Department of Chemistry and Biochemistry, The Institute for Cellular and Molecular Biology, and The Center for Nano and Molecular Science and Technology, The University of Texas, Austin, Texas 78712, USA.
Allen
Richard
R
Plenert
Matthew L
ML
Okerberg
Eric
E
Gordon
Mary Jane
MJ
Shear
Jason B
JB
D000537:Aluminum Oxide; D001703:Biophysics / Q000379:methods*; D007834:Lasers; D008027:Light; D008856:Microscopy, Fluorescence; D008956:Models, Chemical; D009991:Oscillometry; D010100:Oxygen / Q000378:metabolism; D010777:Photochemistry / Q000379:methods*; D017785:Photons; D011522:Protons; D012701:Serotonin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014025:Titanium
D011522:Protons; D012701:Serotonin; D014025:Titanium; D000537:Aluminum Oxide; D010100:Oxygen