Narrowband Plasmonic Absorber Using Gold Nanoparticle Arrays for Refractive Index Sensing

Here, a design of localized surface plasmon resonance (LSPR)-based sensor using narrowband metamaterial absorber based on a gold nanoparticle array is studied. The LSPR based sensor has found comprehensive applications in clinical analysis and environmental monitoring. The simulation outcomes demonstrate that the proposed structure has an absorption bandwidth (FWHM) of 5.7nm. Sensors with narrow bandwidth can develop efficiency and correctness detection. Furthermore, as a refractive index sensor, the sensitivity is obtained as high as S = 964nm/RIU with large value of figure of merit (FOM =
$1.653\times 10$
⁴
RIU
⁻¹
). The proposed design displays polarization independence, which will remove the polarization requirement of equipment. We further demonstrate the array as a biosensor for detecting some viruses, suggesting the applicability for label-free clinical sensing. The device has an extensive performance, such as perfect absorption, polarization insensitivity, high sensitivity, and FOM, appropriate for applied applications.