Hassler, K.Leutenegger, M.Rigler, P.Rao, R.Rigler, R.Gosch, M.Lasser, T.2006-10-032006-10-032006-10-03200510.1364/OPEX.13.007415https://infoscience.epfl.ch/handle/20.500.14299/234930WOS:0002320582000187496We designed a fluorescence correlation spectroscopy (FCS) system for measurements on surfaces. The system consists of an objective-type total internal reflection fluorescence (TIRF) microscopy setup, adapted to measure FCS. Here, the fluorescence exciting evanescent wave is generated by epi-illumination through the periphery of a high NA oil-immersion objective. The main advantages with respect to conventional FCS systems are an improvement in terms of counts per molecule (cpm) and a high signal to background ratio. This is demonstrated by investigating diffusion as well as binding and release of single molecules on a glass surface. Furthermore, the size and shape of the molecule detection efficiency (MDE) function was calculated, using a wave-vectorial approach and taking into account the influence of the dielectric interface on the emission properties of fluorophores. (c) 2005 Optical Society of America.(170.6280) Medical optics and biotechnologySpectroscopyfluorescence and luminescence(240.6490) Optics at surfacesSpectroscopysurface(300.2530) SpectroscopyFluorescencelaser-inducedSpectroscopytext::journal::journal article::research article