Hybrid whispering gallery mode/plasmonic chain ring resonators for biosensing

We analyze the physics of hybrid whispering gallery mode resonators formed by arranging a periodic array of epitopes (i.e., gold nano-shells covering silica nano-spheres) around the equator of a silica microsphere. When the epitopes are located at the antinodes of the field of the whispering gallery mode, we find that the field localization properties near the epitopes change drastically as the radius of the epitopes is varied due to the existence of distinct coupling regions of the hybrid resonator. We investigated the application of such resonators for biosensing by calculating the resonance wavelength shift caused by a binding event of a single Thyroglobulin cancer marker protein to the surface of an epitope in the chain. (C) 2014 AIP Publishing LLC.