Enhancing the efficiency of FRET using surface plasmons waves on gold nanogratings

Our lab seeks to enhance the Förster resonance energy transfer (FRET) efficiency using surface plasmons excited on gold nanogratings. Surface plasmons are longitudinal oscillations of conduction electrons that travel along a metal surface. FRET is the transfer of energy between a donor and an acceptor fluorescent molecule, the efficiency of which is strongly dependent on the distance between the donor and acceptor molecules. Additionally, we suspect the surface plasmon enhancement effectiveness depends on the distance between the donor and acceptor and the grating surface. To precisely position the donor and acceptor molecules relative to each other and the gold nanograting, we developed a protocol to use double-stranded DNA as scaffolding. In this work, we varied the distance between the donor and acceptor molecules by adding additional base pairs between them along the same strand of the DNA backbone. The DNA is tethered to the gold nanograting via a thiol attachment to one terminating end. The donor and acceptor molecules were positioned at differing lengths from the nanograting, with the donor positioned closer to the surface.