Enhancement of Fluorescence Resonance Energy Transfer by Surface Plasmon Resonance

The purpose of the three-year project, from Aug. 2010 to July 2013, is to study the influence of surface plasmon resonance of a metallic nanoparticle on the fluorescence resonance energy transfer between two nearby molecules. Experiment A core-shelled metallic nanoparticle will be synthesized by coating a silica-layer on an Au or Ag nanoparticle, and then it will be coated by another outer shell (SiO2) containing two kinds of molecules (donor and acceptor). The distance between these molecules can be controlled by adjusting their concentration and the thickness of shell. The mechanism of SPR on FRET will be also studied by using fluorescence spectroscopy to measure the emission spectrum for identifying the energy transfer efficiency of FRET and the enhancement factors for the donor and acceptor. In addition, another nanostructure- silver island film will be studied for the same purpose. The lifetime reduction by these two structures will be identified. Furthermore, we will combine the two structures to form a dimer structure which has a narrow gap for inducing a coupled SPR to enhance the efficiency of FRET and the fluorescence of donor and acceptors more. Theoretical work and Numerical Simulation The analytical solution of EM field of a spherical coreshell containing an oscillating dipole within the shell will be derived. We will develop software to calculate the energy transfer efficiency of FRET and the enhancement factors for the donor and acceptor in the presence of a metallic nanoparticle. For the simulation of the silver island, the 3D BEM and MMP method will be used to calculate the interaction of two dipoles with a nearby metallic nanostructure. Furthermore, we will analysis a dimer structure, which is the combination of the coreshell and the silver island, to study the influence of coupled SPR on the energy transfer efficiency of FRET and the enhancement factors for the donor and acceptor.

Project ID:PB10101-2543
External Project ID:NSC99-2221-E182-030-MY3