Design Approach of Metallic Nanoparticles Array for Biosensing: Calculation of Enhanced Electronic-Field

We present calculation of enhanced electronic field in a rhombic Ag nanoparticles array induced by localized surface plasmon resonance (LSPR) for the purpose of improving detection resolution of the extinction efficiency for biosensing. The engineered rhombic Ag nanostructures array was designed by means of finite-difference and time-domain (FDTD) algorithm-based computational numerical calculation through both spectrum and electromagnetic field analyses. The extinction efficiency was obtained by theoretical numerical calculation and experimental detection. Moreover, the LSPR-induced enhancement of the electronic field distribution is calculated, and compared to that of the silicon medium. The results show that the rhombic Ag nanostructures array can enhance the localized electric fields near the surface of the metallic array. To verify our calculation results, biotins binding and detection were carried out on the basis of the calculated metallic arrays. It is in agreement to that of the reported results before. This design approach may be a guideline for designing the engineered metallic particles arrays.