TY - JOUR
T1 - Light quenching and depolarization of fluorescence observed with laser pulses. A new experimental opportunity in time-resolved fluorescence spectroscopy
AU - Gryczyński, Ignacy
AU - Bogdanov, Valery
AU - Lakowicz, Joseph R.
PY - 1994/4
Y1 - 1994/4
N2 - We report the first time-resolved studies of quenching of fluorescence by light, i.e. "light quenching". The dye 4-(dicyanomethylene)-2-methyl-6-(p-dimethamino)-4H-pyrane (DCM) was excited in the anti-Stokes region from 560-600 nm. At high illumination power the intensifies of DCM were sub-linear with incident power. The extent of light quenching was proportional to the emission spectrum at the incident wavelength, as expected for light-stimulated decay from the excited state. The frequency-domain intensity decays indicated the effect was not due to heating or other photochemical effects. Importantly, the decay time was unchanged, as expected for light quenching with a single pulsed laser beam, while the time-zero anisotropy was decreased due to orientation-dependent quenching of the excited state population. Light quenching of fluorescence provides a new method to control the excited state population and orientation of fluorophores, and offers new experimental opportunities for biophysical applications of time-resolved fluorescence.
AB - We report the first time-resolved studies of quenching of fluorescence by light, i.e. "light quenching". The dye 4-(dicyanomethylene)-2-methyl-6-(p-dimethamino)-4H-pyrane (DCM) was excited in the anti-Stokes region from 560-600 nm. At high illumination power the intensifies of DCM were sub-linear with incident power. The extent of light quenching was proportional to the emission spectrum at the incident wavelength, as expected for light-stimulated decay from the excited state. The frequency-domain intensity decays indicated the effect was not due to heating or other photochemical effects. Importantly, the decay time was unchanged, as expected for light quenching with a single pulsed laser beam, while the time-zero anisotropy was decreased due to orientation-dependent quenching of the excited state population. Light quenching of fluorescence provides a new method to control the excited state population and orientation of fluorophores, and offers new experimental opportunities for biophysical applications of time-resolved fluorescence.
KW - Anisotropy
KW - DCM
KW - Fluorophores
KW - Time-resolved fluorescence: Quenching
UR - http://www.scopus.com/inward/record.url?scp=0028260261&partnerID=8YFLogxK
U2 - 10.1016/0301-4622(93)E0072-D
DO - 10.1016/0301-4622(93)E0072-D
M3 - Article
C2 - 8018819
AN - SCOPUS:0028260261
VL - 49
SP - 223
EP - 232
JO - Biophysical Chemistry
JF - Biophysical Chemistry
SN - 0301-4622
IS - 3
ER -