A hollow rectangular plasmonic absorber for nano biosensing applications

In this paper, we have introduced a hollow rectangular plasmonic absorber for Terahertz region. The result of our study shows that the nanoparticle absorber delivers a high absorbance of 90%, and enhances the electric field drastically as six times, which makes it an ideal choice for biosensing applications. The effect of the particle size and surface topology is investigated to maximize the absorbance of the structure and can be noticed for frequency tuning. In addition, for biosensing applications, the shift in the resonance frequency and the Figure of Merit (FOM) was studied by exposing the nanoparticles with different biomaterials. The results revealed that by concentrating the energy, we will be able to distinguish different materials with a very high accuracy. As a matter of fact, the parametric studies indicate that the suggested structure has outstanding resonance frequency stability. Therefore, the predictable fabrication distortion has less effect on frequency shift and absorbance and consequently, this particle is advantageous for commercial optical applications such as the solar cell.