Core–Shell Nanoparticles Based Optical Cross-Section Determination for Enhanced Sensing and Surface Plasmon Resonance Applications in Wireless Sensor Networks

Core–shell nanoparticles (CSNs) have attracted significant attention in the field of optical sensing and surface plasmon resonance (SPR) applications due to their unique optical properties, which can be tailored through control of their size, composition, and core-shell architecture. This study presents a comprehensive analysis of the optical cross-sections (extinction, scattering, and absorption) of core-shell nanoparticles, focusing on their potential for enhancing the sensitivity and accuracy of SPR-based sensors. The extinction, scattering, and absorption cross-sections of CSNs were evaluated through theoretical models and numerical simulations, with the results showing a strong dependence on the shell material, shell thickness, and the wavelength of incident light. A maximum extinction cross-section of 5.12 × 10 −15 m 2 was observed for CSNs with a gold core and a silver shell at a wavelength of 532 nm, demonstrating their potential for high-performance SPR applications. Additionally, the scattering cross-section was found to be 2.86 × 10 −16 m 2 , and the absorption cross-section was 1.26 × 10 −16 m 2 under similar experimental conditions. The results highlight the significant enhancement of optical properties through the core–shell structure, making them ideal candidates for use in biosensing, environmental monitoring, and medical diagnostics.