FDTD Simulations of Shell Scattering in Au@SiO2 Core–Shell Nanorods with SERS Activity for Sensory Purposes

Abstract

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@SiO2 system. Three excitation linewidths (λ = 532, 632.8, and 785 nm) were used for theoretical experiments. Electric field parameters for Au nanorods, Au@SiO2 nanorods, and hollow SiO2 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 × 107 and was obtained on a rod with a SiO2 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@SiO2 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.

Synthesis, characterization, and performance evaluation of polyamide‐Ag@SiO2 Raman substrate

“…In addition, it is capable of solving the broadband problem at a time and obtaining the electromagnetic field distribution directly. It has been demonstrated that FDTD can be applied successfully to the study of SERS properties of typical systems, such as core‐shell structures and periodic metal arrays 25,26 . By using FDTD method, we were able to gain a better understanding of the electromagnetic enhancement mechanism of SERS in order to prepare more excellent SERS substrate by theoretically analyzing the electric field distribution and the “hotspot” position on the PA‐Ag@SiO 2 thin film substrate.…”

Paper Lateral Flow Strips Based on Gold Nanorods for Ultrasensitive Detection of Traumatic Brain Injury Biomarkers

“…To experimentally address this problem, a novel SERS-PFL based on optimal AR of AuNRs was first developed to realize facile, visual, and sensitive detection of GFAP and BMP in TBI. By optimizing the fabrication parameters, AuNRs with greatly enhanced SERS activity were synthesized and then analyzed by the finite-difference time-domain (FDTD) method. , Using the optimized AuNRs, a SERS probe was prepared by modifying the Raman reporter (THI) and corresponding antibodies (GFAP and MBP) on the surface of the optimal AuNRs. The SERS probes obtained could provide specific binding sites for bioconjugation with antigens to develop a Raman reporter on Au nanorod antibodies and recombine with secondary antibodies.…”