A high-sensitivity biosensor based on a metal–insulator–metal diamond resonator and application for biochemical and environment detections

Abstract

In this paper, a novel Refractive Index (RI) sensor on tunable plasmonic nanostructures in the near-infrared (NIR) and mid-infrared (MIR) range has been investigated, using metal-insulator-metal (MIM) and a couple of hexagonal, trapezoid, and diamond cavity (HTD) shapes. The proposed biosensor has a potential biochemical application such as glucose in water and temperature, the numerical results were obtained from the Finite-Difference-Time-Domain (FDTD) method. By optimizing the parameters of the proposed structure, we achieved maximum sensitivity reaching 5155 nm per refractive index unit (RIU), and an extensive range of refractive index from 1 to 1.7 makes the sensor suitable for biochemical as well as medical diagnostic applications, with wavelength resolution reaching as high as 3.5 × 106 RIU−1. Due to its high sensitivity, this structure could pave the way for the development of a feature plasmonic biosensor, sharp spectral response, small size, and wide detection range.