Novel hyperpolarizable and fluorescent dyes in lipid membranes: studying membrane potentials using nonlinear optical and fluorescence - Bechem, M.; Beutner, S.; Burkhardt, N.; Fuchs, C.; Kryschi, C.; Paffhausen, W.; Reiffers, B.; Schade, A.; Schlue, W.-R.; Schmid, D.; Schneider, L.; Schulte, P.; et al. (Electrochimica Acta, 2003)