Retinol fluorescence: a simple method to differentiate different bilayer morphologies

The fluorescence spectra of retinol obtained in bilayer structures of two different systems with dodecyl tetraethylenglycol ether are shown. A correlation between the fluorescence intensity of retinol and the different topologies of bilayers has been found. We have tested this correlation with the C 12 E 4 /benzyl alcohol/water system, and we have also applied this idea to the study of the lamellar phases of the C 12 E 4 /PEG/water system. The highest fluorescence intensity of retinol corresponds to unilamellar vesicles, while the lowest is observed for multilamellar vesicles. The kinetic study of the degradation of vitamin A in these media is also related to the different microstructures of the bilayers.