TIME-RESOLVED EMISSION-SPECTROSCOPY OF THE DANSYL FLUORESCENCE PROBE

Abstract

Using a cavity-dumped laser system as the light source, we have recorded time-resolved fluorescence spectra for the dansyl group in a variety of systems. The fluorescence spectrum of dansylphosphatidylethanolamine incorporated into a variety of lipid bilayer systems at ambient temperatures shows very marked time dependence, with red shifts of up to 40 nm over a 40-ns period. Similarly, large red shifts are observed for dansylamide in 1-butanol at low temperatures, which can be tentatively attributed to the initial rapid formation of an intramolecular charge transfer state, followed by reorientation of the polar solvent molecules. The time-resolved behavior in the lipid bilayer system can, by..