Plasmon-enhanced fluorescence in heterochlorophyllous peridinin-chlorophyll-protein photosynthetic complex

We study the fluorescence properties of peridinin-chlorophyll-protein light-harvesting complex reconstituted with both chlorophyll a and chlorophyll b coupled to spherical gold nanoparticles. Since there is a bidirectional energy transfer between the chlorophylls, the impact of plasmon excitations upon the energy transfer dynamics can be studied in such a hybrid nanostructure. The results show that the emission of both chlorophyll a and chlorophyll b in a reconstituted PCP is strongly enhanced when the light-harvesting complexes are separated from the metallic nanoparticles by a 12-nm-thick SiO2 layer, the average enhancement reaches a factor of 8. The analysis of fluorescence decay curves indicates that the energy transfer between chlorophyll a and chlorophyll b is also influenced by plasmon excitations in gold nanoparticles.

► Fabrication of plasmonic nanostructure with controlled dielectric spacer. ► Observation of emission enhancement of both Chl a and Chl b in a PCP complex. ► Detection of spectral signatures of plasmon induced changes of the energy transfer.