Optimized Design and Performance Analysis of X-Shaped Gold Plasmonic Nanoantenna on SiC for High-Sensitivity Biosensing Applications
摘要
The design and functionality of an X-shaped gold plasmonic nanoantenna integrated with a silicon carbide (SiC) substrate for high-sensitivity biosensing applications are investigated numerically in this study. In order to maximize the structure’s sensing capabilities, the study investigates its electromagnetic behavior under various refractive indices using COMSOL Multiphysics®. Extremely sensitive biomolecule detection is made possible by the X-shaped bowtie geometry’s enhanced plasmonic coupling and electric field localization in the nanogap. A better refractive index sensitivity of 3561.16 nm/RIU, a high-quality factor of 169.25, and the greatest figure of merit (FOM) of 1411.11 RIU⁻¹ among several traditional plasmonic biosensors are the primary performance parameters. Field analysis confirms that the optimal nanogap widths for both magnetic and electric field confinement are less than 20 nm. Additionally, reflection analysis shows a noticeable resonance dip at about 495 nm with ideal impedance matching, and the absorption spectrum shows broadband plasmonic resonance with maximal absorption within the visible spectrum. These characteristics support the design’s usefulness for medical diagnostics, environmental monitoring, and label-free biosensing. The X-shaped plasmonic nanoantenna created here offers an extremely small, inexpensive, and highly efficient platform, paving the way for the development of next-generation optical biosensors.