Detection of single biomolecule fluorescence excited through energy transfer: Application to light-harvesting complexes

Abstract

The authors show that energy transfer is a feasible mechanism for exciting fluorescence of single light-harvesting complexes with different characters of the fluorescing state. This approach is applied for excitons consisting of 18 strongly coupled bacteriochlorophylls in light-harvesting complex 2 as well as for peridinin-chlorophyll-protein monomers containing either two chlorophyll a molecules or a pair of chlorophyll a and chlorophyll b characterized with the emission energy difference of 400cm−1. Using this method the authors are able to observe fluorescence spectral dynamics on the scale comparable or larger than the emission linewidth of a single chromophore.