Imaging of fluorescence enhancement in photosynthetic complexes coupled to silver nanowires

Optical microscopy and spectroscopy of hybrid nanostructures composed of chlorophyll-containing photosynthetic complexes and silver nanowires reveal strong enhancement of fluorescence intensity of chlorophylls bound to the protein. This effect results from interaction between excited states of molecules embedded in the photosynthetic complex and plasmon excitations in metallic nanowires. Wide-field microscopy images reveal twofold increase of the emission intensity for complexes located at the ends of the nanowires as compared to the ones lying along the nanowires. Complementary spectrally and temporally resolved experiments indicate about 10-fold average increase of the chlorophyll fluorescence rate upon coupling with the metallic nanoparticles. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4794171]