The singlet excitation transfer and trapping kinetics in photosynthetic membranes in case of low excitation intensities is studied by spectrally selective picosecond-time- domain fluorescence spectroscopy and by numerical integration of an appropriate system of equations. The essential features of our models are spectral heterogeneity of the light- harvesting antenna, inclusion of temperature effects, nonabsolute excitation traps, correlation between spectral and spatial parmeters. A reasonably good agreement between theoretical and experimental fluorescence decay kinetics for several purple photosynthetic bacteria has been achieved. This comparison gives several interesting numerical constants characterizing microscopic excitation transfer between different light-harvesting-antenna pigment-protein complexes towards the reaction centres. Some aspects of the experiment are also discussed.

Date Published: 1 May 1990
PDF: 9 pages
Proc. SPIE 1204, Time-Resolved Laser Spectroscopy in Biochemistry II, (1 May 1990);

Published in SPIE Proceedings Vol. 1204:
Time-Resolved Laser Spectroscopy in Biochemistry II
Joseph R. Lakowicz, Editor(s)