FDTD Simulations of Shell Scattering in Au@SiO(2) Core-Shell Nanorods with SERS Activity for Sensory Purposes.

The article describes the results of Finite-Difference Time-Domain (FDTD) mathematical modeling of electromagnetic field parameters near the surfaces of core-shell gold-based nanorods in the Au@SiO(2) system. Three excitation linewidths (λ = 532, 632.8, and 785 nm) were used for theoretical experiments. Electric field parameters for Au nanorods, Au@SiO(2) nanorods, and hollow SiO(2) shells have been calculated and evaluated. The correlations between electric field calculated parameters with nanorod morphology and shell size parameters have been clarified. The optical properties of nanoobjects have been simulated and discussed. The highest maximum calculated value of the electric field tension was E = 7.34 V/m. The enhancement coefficient was |E/E0|4 = 3.15 × 10(7) and was obtained on a rod with a SiO(2) shell with dimensional parameters of height 70 nm, rod width 20 nm, and shell thickness 20 nm. As a result, a flexible simulation algorithm has been developed for the simulation of electric field parameters in each component of the Au@SiO(2) system. The developed simulation algorithm will be applicable in the future for any other calculations of optical parameters in any similar component of the core-shell system.