Metal-enhanced fluorescence of chlorophylls in light-harvesting complexes coupled to silver nanowires

Hybrid nanostructures consisting of silver nanowires and peridinin-chlorophyll-protein light-harvesting complexes were investigated using wide-field optical fluorescence microscopy. For peridinin-chlorophyll-protein complexes placed in the vicinity to the silver nanowires we observe higher intensities of fluorescence emission as compared to the reference sample, where no nanowires are present. In particular we study two different sample geometries: first, in which the light-harvesting complexes are deposited onto silver nanowires, and second, where solution of both nanostructures are mixed prior deposition on a substrate. Enhancement factors estimated for the former sample were generally smaller in comparison to the other geometry. Analysis of movies with respect to temporal intensity variations for photosynthetic complexes located along and at the ends of the nanowires, indicate that the photostability is unaffected by the interaction with plasmonic excitations in metallic nanoparticles. Therefore, we conclude that in the case of studied hybrid nanostructures coupling with metallic nanoparticles results in higher number of photons emitted from chlorophyll molecules.