title: Visualization of membrane rafts using a perylene monoimide derivative and fluorescence lifetime imaging.
abstract: A new membrane probe, based on the perylene imide chromophore, with excellent photophysical properties (high absorption coefficient, quantum yield (QY) approximately 1, high photostability) and excited in the visible domain is proposed for the study of membrane rafts. Visualization of separation between the liquid-ordered (Lo) and the liquid-disordered (Ld) phases can be achieved in artificial membranes by fluorescence lifetime imaging due to the different decay times of the membrane probe in the two phases. Rafts on micrometer-scale in cell membranes due to cellular activation can also be observed by this method. The decay time of the dye in the Lo phase is higher than in organic solvents where its QY is 1. This allows proposing a (possible general) mechanism for the decay time increase in the Lo phase, based on the local field effects of the surrounding molecules. For other fluorophores with QY<1, the suggested mechanism could also contribute, in addition to effects reducing the nonradiative decay pathways, to an increase of the fluorescence decay time in the Lo phase.
authors.affiliation: Laboratory of Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Anca
authors.initials: A
authors.lastname: Margineanu
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hotta
authors.forename: Renaud A L
authors.initials: RA
authors.lastname: Vallée
authors.forename: Mark
authors.initials: M
authors.lastname: Van der Auweraer
authors.forename: Marcel
authors.initials: M
authors.lastname: Ameloot
authors.forename: Alina
authors.initials: A
authors.lastname: Stefan
authors.forename: David
authors.initials: D
authors.lastname: Beljonne
authors.forename: Yves
authors.initials: Y
authors.lastname: Engelborghs
authors.forename: Andreas
authors.initials: A
authors.lastname: Herrmann
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Frans C
authors.initials: FC
authors.lastname: De Schryver
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D021962:Membrane Microdomains / Q000737:chemistry* / Q000648:ultrastructure*; D008856:Microscopy, Fluorescence / Q000379:methods*; D008968:Molecular Conformation; D015336:Molecular Probe Techniques; D010569:Perylene / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D010569:Perylene