Design of a plasmonic metasurface for refractive index sensing of aqueous glucose

Abstract

In this paper, a new plasmonic absorbing metasurface sensor has been proposed to determine glucose concentrations. Surface Plasmon Resonance (SPR) shift has been used as the indicator of glucose concentration. The sensor employs metal-dielectric-metal configuration along with metal nano-cylinders to provide near unity absorption in the near infrared wavelength range (1800- 2200 nm). The absorption frequency shifts when the sensor is surrounded by materials of different refractive indices. The structure has been investigated through Finite Difference Time Domain (FDTD) simulations. The results show reflectance and absorbance peaks with different analyte concentrations. The sensor displays a linear response along with sensitivity and Figure of Merit (FOM) equal to almost 500 nm/RIU and 11.82 RIU-1, respectively. The proposed sensor has potential applications in food and biomedical industries.