All-Opto Plasmonic-Controlled Bulk and Surface Sensitivity Analysis of a Paired Nano-Structured Antenna with a Label-Free Detection Approach

Gold nanoantennas have been used in a variety of biomedical applications due to their attractive electronic and optical properties, which are shape- size-dependent. Here, periodic paired gold nanostructure exploiting surface plasmon resonance is proposed, shows promising results for Refractive Index (RI) detection its high electric field confinement diffraction limit. single nanostructured sensors were designed real-time RI detection. The Full-Width at Half-Maximum (FWHM) Figure-Of-Merit (FOM) also calculated, relate the sensitivity sharpness peak. effect different possible structural shapes dimensions studied optimise response nanosensing structures identify an optimised elliptical nanoantenna with major axis a, minor b, gap between pair g, heights h being 100 nm, 10 40 respectively. In this work, we investigated bulk sensitivity, spectral shift per refractive index unit change surrounding material, value was calculated as 526–530 nm/RIU, while FWHM around 110 nm FOM 8.1. On other hand, sensing related variation layer near surface, same antenna 250 nm/RIU thickness 4.5 nm.