(591a) Ag-Cu Bimetallic Nanoparticles for Metal Enhanced Luminescence (MEL)

Metal enhanced luminescence (MEL) of certain luminophores in the presence of metallic nanoparticles can help enhance the fluoroscence detection of a wide variety of biomolecules.  Using bimetallic nanoparticles is an attractive option because important optical properties, like the wavelength corresponding to the surface plasmon resonance (SPR) peak and the scattering efficiency that dictate the enhancement/quenching of luminophore molecules, can easily be tuned  by adjusting the composition, morphology, size and shape of the nanoparticles. In this study, we explore the luminescence enhancement of Cy3 dye in the vicinity of Ag-Cu bimetallic nanoparticles.  We used Finite Difference Time Domain (FDTD) calculations to study the influence of composition on the AgxCu1-x bimetallic nanoparticles.  Nanoparticles of various structures like alloys, core-shell and mixed metal substrates with spherical and cubical shapes, and in the size range of 25-200 nm are studied with a varying fluorophore-particle separation distance.  Optimizing these parameters provides a guiding principle for the synthesizing the bimetallic nanoparticles that can yield high fluoroscence enhancements.  The calculations were validated using bimetallic particles synthesized using the polyol synthesis process.  The fluoroscence enhancements were measured using a confocal microscope.