Critical density fluctuations in lipid bilayers detected by fluorescence lifetime heterogeneity

摘要: The heterogeneity of the decay fluorescence transparinaric acid in single-component lipid bilayers at temperatures above their gel/liquid crystalline phase transition is shown to be due presence regions higher local density and acyl chain order than predominant fluid regions. This conclusion based on selective excitation behavior observation time-resolved anisotropies that increase long times. fractional amplitude lifetime component shows a temperature variation conforms conventional descriptions critical behavior. exponent extracted from this 1.1, close value 1.0 describes ultrasonic data. We therefore conclude liquid exhibit with significant fluctuations. must taken into account interpretation other spectroscopic measurements properties bilayers.