Quantitative characterization of light-harvesting efficiency in single molecules and nanoparticles by 2D polarization microscopy: Experimental and theoretical challenges

General problem of extracting intramolecular energy transfer information from fluorescence and fluorescence excitation polarization experiments at single molecule level is presented. A single funnel approximation is shown to be a very powerful approach to model the polarization data obtained by recently emerged 2-dimensional polarization single molecule imaging technique [O. Mirzov et al., Small 5 (2009) 1877]. Using this approximation a parameter characterising quantitatively light-harvesting efficiency of an individual light-harvesting antenna can be readily obtained. Technical details of 2D polarization imaging and practical methods of avoiding polarization artefact in fluorescence microscopy are discussed. (C) 2012 Elsevier B. V. All rights reserved.