Tuning sensitivity and limit of detection of nanoparticle dimer based on SiO2@Au core-shell for breast cancer diagnosis and prediction of treatment benefit

Abstract

For many years, Mammographic screening has been considered as the most utilized tool for clinical diagnosis of breast cancer. However, when it comes to tumors with small size, particularly those located deep in the breast or behind dense tissue, Mammography is unable to detect the presence of tiny nodules in the breast, making it less suitable for the early diagnosis of breast cancer. The early prognosis remains, hence, a challenging task for public health worldwide. This theoretical study focuses on the design and computational analysis of SiO2@Au core-shell nanoparticle dimers for potential application in breast cancer detection using serological tests. The study uses the well-known Finite-Difference Time-Domain (FDTD) method to simulate and study the role of the proposed configuration in enhancing the electric field intensity at the hot-spot. To design our configurations, we use the golden ratio constant (φ), which enables the determination of the core and the shell radii that yield the optimal response in terms of the absorption spectrum and the electric field enhancement. Our results show that the proposed approach significantly enhances the electric field intensity at the hot-spot, achieving an amplification factor of 1.9 × 10³. This enhancement amplifies the interaction between light and the targeted molecules located at the hot spot, thereby improving detection sensitivity. Furthermore, the detection limit reaches 0. 4 × 10⁻⁶ RIU, which is several times lower than that of conventional LSPR sensors. These enhanced performance characteristics of the proposed configuration pave the way for its use in high-precision breast cancer diagnosis and prediction of treatment benefits.