Plasmon resonance dynamics and enhancement effects in tris(2,2'-bipyridine)ruthenium(II) gold nanosphere oligomers.

Ruthenium-based metal complexes are one of the most widely studied dyes because of their rich photochemistry and light-harvesting properties. Significant attention has been paid to the energy and charge transfer dynamics of these dyes on semiconductor substrates. However, studies on photophysical and photochemical properties of these dyes in plasmonic environments are rare. In this study, we report a plasmon-mediated resonance energy transfer in an optimized oligomer system that enhances the photoexcited population of the well known dye, tris(2,2'-bipyridine)ruthenium(II), [Ru(BPY)] adsorbed on gold nanosphere surfaces with a defluorescenced Raman signal. Structural and chemical information is collected using a range of techniques that include time-resolved UV/VIS, DLS, SERS, and TA. The findings have great potential to impact nanoscience broadly with special emphasis on surface photocatalysis, redox chemistry, and solar energy harvesting.