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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 16: POSTERS Polyelectrolytes and Biological Systems

CPP 16.3: Poster

Dienstag, 24. März 2009, 14:00–16:30, P3

Fluorescence Lifetime Measurements of Molecular Crystals and Giant Unilamellar Vesicles — •Marek Blaszczynski and Lothar Kador — University of Bayreuth, Institute of Physics and BIMF, D-95440 Bayreuth, Germany

Fluorescence lifetime imaging microscopy in the frequency domain is applied to mixed molecular crystals and giant unilamellar vesicles (GUVs). The custom-built set-up is based on a confocal microscope and uses a cw laser which is amplitude-modulated in the MHz regime with an acousto-optic moculator (AOM). The phase shift and modulation amplitude of the fluorescence signal with respect to the excitation yield information about the fluorescence lifetime(s). The fluorescence decay of pentacene in p-terphenyl host crystals shows a bi-exponential behavior, which is ascribed to the presence of pentacene monomers and dimers. Spatially resolved studies on GUVs of binary mixtures (DOPC/DPPC) and ternary mixtures (DOPC/DPPC/cholesterol) with the head-labelled phospholipid Rhod-DMPE as a fluorescent probe were performed, and preliminary results of their phase behavior are presented.