Triangular Nanoparticle Based Plasmonic Biosensor

Abstract

This paper presents the theoretical investigationof a novel metal-insulator-metal based plasmonic perfect absorber for biosensing applications.The electromagnetic simulations are performed using finite integration technique (FIT) based simulation softrware i.e. CST Microwave Studio. The electromagnetic analysis are useful in demonstrating the effect of field enhancement in the sensing region of a biosensor. It also depicts the spectral shift of field enhancementas a function of variations in the refractive indices of a sensing medium defined as a sensitivity of biosensor. If the spectral shift is high with a small variation in refractive index ofa sensing medium, then sensor is said to be a highly sensitive. The sensitivity of a plasmonic sensors depend on the geometry of the structure. Here, a novel metal-insulator-metal based PPA structure is considered for analysis. The novel approach uses triangular gold nanoparticles at the vicinity of the sensing medium. Due to the sharp edges of the triangular nanoparticles, high field is enhanced towards the sensing medium as compared to the conventional metal-insulator-metal based PPA biosensors. The simulation results show effects of field enhancement, spectral shifts of the absorption in the sensitivity. Results are useful for the design of a novel PPA biosensor.