Design and Development of Efficient Plasmonic Sensors Based on Bi-Layer of Silver-SiO2 Nanodisk Arrays

In this paper, a bi-layer of silver-SiO
₂
nanodisk array has been employed aiming to realize efficient plasmonic sensors within the visible spectrum. Utilization of silver nanodisk arrays results in narrow and enhanced extinction spectra while the SiO
₂
layer enhances the extraordinary optical transmission (EOT) of light and protects the silver surface from oxidation. Using numerical simulations, it has been demonstrated that the designed sensor shows high refractive index sensitivities as large as 390nm/RIU with a figure of merit of 10.5 RIU
^-1
proving the efficacy of the design. The proposed scheme is polarization insensitive thanks to it symmetric configuration taking advantage of low cost compared with gold-based sensors. The designed nanostructure provides a good reliability using the SiO
₂
layer offering potential applications for chemical and biological sensing.