Localized Surface Plasmon Resonance Sensor Based at Metallic Sphere Dimer Particle.

Simulated transmission spectrums of the sphere dimer nanoparticle and the nanoshell structure by the Finite-Difference time-Domain method are present. The considered structure is silver or SiO₂ dimer nanoparticle and nanoshell structures, and the particle distance is 10 nm. There is little transmission dip in the transmission spectrums for the silver dimer nanoparticle and nanoshell structure in the visible wavelength range, which arisen from the excitation of the Localized Surface Plasmon Resonance. The transmission dip sensitivity with the index refractive for the silver dimer nanoparticle is about 80 nm RIU–1. Meanwhile, the electric field enhancement and localization properties of the Silver dimer nanoparticle is better than that of the SiO₂ dimer nanoparticle. Meanwhile, these structures can extensively apply to biochemical sensor devices design and localized field enhancement device so on.