Coupled surface plasmon resonance on gold nanocubes - investigation by simulation

The refractive index sensitivity of coupled plasmonic nanostructures, namely gold nanocubes in various arrangements, were simulated with the MNPBEM Matlab toolbox. The size of the cubes, the distance between the particles were the running parameters. It was found that the enhancement factor (which characterize the increase in the peak shift for multi-particle arrangements compared to single-particle models) is an exponential function of (D/a) where D is the gap between the particles and a is the edge length of the cube. It was also found that significant plasmonic coupling effects starts below 0.5 D/a for cubical nanoparticles.