Simulation and Analysis of Ring Shape Metal–Insulator-Metal Plasmonic Biosensors for the Detection of Prostate-Specific Antigen (PSA).

In this paper, a plasmonic refractive index sensor based on metal–insulator-metal (MIM) topology in the form of a nanoring was investigated for the detection of prostate-specific antigen (PSA), which was validated using the finite-difference time-domain (FDTD) three-dimensional numerical equation method. We have tried to get the most optimal state of the nanoring-shaped sensor using various simulations. Here, two different types of metals (Au and Ag) in two different shapes of ring and disk were examined. The results of this study show the superiority of nanoring-shaped sensors to disk and the relative superiority of Ag to Au. The highest sensitivity and FOM for detecting PSA in the Ag nanoring shape are 567.23 and 3.72 nm/RIU, respectively, while these values are 478.34 and 2.91 nm/RIU for disk shapes, respectively. The wavelength range of the sensor is very close to the information communication window. In addition to its remarkable sensor capability, it can also be used in optical electronics applications such as optical switching, amplifiers, and all-optical plasmon modulators. [ABSTRACT FROM AUTHOR]