Fabrication and sensing application of a silver nanoshell array structure by a micro-flow injection method.

A two-dimensional periodic metallic spherical shell array structure with controllable geometric parameters was fabricated on the target substrate by microsphere templating and magnetron sputtering. The micro-flow injection method was used to prepare a two-dimensional colloidal microsphere template, and reactive ion etching (RIE) was used to change the spherical spacing. The geometric parameters and spectral characteristics of the spherical shell array structure were analyzed with the simulation software FDTD solutions. The nanostructural morphology and optical properties of the samples were characterized by scanning electron microscopy (SEM) and optical spectral analysis (OSA). The refractive index sensing application based on the principle of the local surface plasmon resonance (LSPR) and plasmonic interference was realized. The results show that the spherical shell arrays structure is sensitive to the surrounding environment, the refractive index sensitivity of spherical shell array structure is 527.07 nm per RIU and 922.25 nm per RIU, and the quality factor FOM is 16.5 and 15.3, respectively. The techniques demonstrated can produce large-area periodic nanostructure arrays with ultra-large production in cost-competitive ways. In addition, these properties make them applicable to multiple applications, such as surface plasmon sensors and various optical device.