Refractive index sensing: study and analysis for SARS-CoV-2 detection

This article presented a sensing method for detecting SARS-CoV-2 based on refractive index (RI). The approach utilizes the established nanogap terahertz metamaterial unit cell design as a biosensor. The underlying idea is that the SARS-CoV-2 virus can be treated as a nanoparticle, falling within the 30–100 nm diameter range. Therefore, it can be detected using established and dependable photonics methods. Notably, the SARS-CoV-2 virus family exhibits a negative RI between − 0.96 and − 1. Absorption coefficient ( α ) is 226,615.2 cm −1 , absorption rate is 97% and sensitivity ( S ) is 330 nm / RIU . The analysis shows a minimal deviation in absorption and resonant frequency when varying the thickness of the dielectric clad from 30 to 100 nm. This stability makes it a suitable outcome for sensing SARS-CoV-2.