Three-photon-induced fluorescence of diphenylhexatriene in solvents and lipid bilayers |
| |
Authors: | Henryk Malak Ignacy Gryczynski Jonathan D Dattelbaum Joseph R Lakowicz |
| |
Institution: | (1) Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, School of Medicine, 725 West Lombard Street, 21201 Baltimore, Maryland |
| |
Abstract: | We observed the emission of l,6-diphenyl-l,3,5-hexatriene (DPH) when excited with the fundamental output of a fs Ti:sapphire
laser at 860 nm. The emission spectra of DPH were identical to that observed for one-photon excitation at 287 nm. The dependence
of the DPH emission intensity on laser power was cubic, indicating three-photon excitation of DPH at 860 nm. At a shorter
wavelength of 810 nm, the dependence on laser power was quadratic, indicating a two-photon process. At an intermediate wavelength
of 830 nm the mode of excitation was a mixture of two- and three-photon excitation. At 830 nm the anisotropy is no longer
a molecular parameter, and the mode of excitation and anisotropy of DPH depends on laser power. Frequency-domain anisotropy
decays of DPH in triacetin revealed the same rotational correlation times for two- and three-photon excitation. However, the
time 0 anisotropy of DPH was larger for three-photon excitation than for two-photon excitation. Steady-state anisotropy data
for DPH-labeled membranes revealed the same transition temperature for one- and three-photon excitation. These anisotropy
data indicate that membrane heating was not significant with three-photon excitation and that three-photon excitation may
thus be of practical usefulness in fluorescence spectroscopy and microscopy of membranes. |
| |
Keywords: | Fluorescence intensity decays anisotropy decays multiphoton excitation three-photon excitation two-photon excitation diphenylhexatriene membranes |
本文献已被 SpringerLink 等数据库收录! |
|