Dual Fluorescence Phenomenon in ‘Push-Pull’ Stilbenes

Fluorescence spectroscopy-based techniques using conventional fluo- rimeters have been extensively applied since the late 1960s to study different aspects of membrane-related phenomena, i.e., mainly relating to lipid-lipid and lipid-protein (peptide) interactions. Even though fluorescence spectroscopy approaches provide very valuable structurally and dynamically related information on membranes, they generally produce mean parameters from data collected on bulk solutions of many vesicles and lack direct information on the spatial organization at the level of sin- gle membranes, a quality that can be provided by microscopy-related techniques. In this chapter, I will attempt to summarize representative examples concerning how microscopy (which provides information on membrane lateral organization by direct visualization) and spectroscopy techniques (which provides information about molecular interaction, order and microenvironment) can be combined to give a powerful new approach to study membrane-related phenomena. Additionally along this chapter, it will be discussed how membrane model systems can be further utilized to gain information about particular membrane-related process like pro- tein(peptide)/membrane interactions.