Light quenching and depolarization of fluorescence observed with laser pulses. A new experimental opportunity in time-resolved fluorescence spectroscopy
| Autor: | Valery Bogdanov, Joseph R. Lakowicz, Ignacy Gryczynski |
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| Rok vydání: | 1994 |
| Předmět: |
Quenching (fluorescence)
Light Chemistry Lasers Organic Chemistry Biophysics Photochemistry Laser Biochemistry Fluorescence Fluorescence spectroscopy law.invention Spectrometry Fluorescence Resonance fluorescence law Excited state Anisotropy Atomic physics Time-resolved spectroscopy Laser-induced fluorescence Fluorescent Dyes |
| Zdroj: | Biophysical Chemistry. 49:223-232 |
| ISSN: | 0301-4622 |
| DOI: | 10.1016/0301-4622(93)e0072-d |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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