Time-resolved fluorescence on self-assembly membranes

Time-resolved fluorescence spectroscopy is an established, sensitive technique for obtaining dynamical and structural information on self-aggregating molecular systems such as micelles, bilayers or monolayers. Because of the nanosecond duration of the excited state each intra- or intermolecular process that affects the lifetime of the excited state can be quantified and ‘translated’ in dynamical and structural factors. Time-resolved fluorescence quenching has evolved as a standard tool to obtain micellar sizes. The same argument applies for fluorescence energy transfer (which acts as a nanometer ruler) between donor and acceptor molecules and for time-resolved fluorescence anisotropy measurements (which provide rotational information). Significant progress has been made with the development of fluorescence decay models and algorithms to analyze experimental data. A new trend in the fluorescence field has emerged from the ‘single molecule’ sensitivity that has been reached and also recently applied to membrane science.