Tunable Nanoplasmonic Transducers: Performance Analysis and Potential Application

Plasmonic nanostructures with tunable optical properties can have many different applications, including high-sensitivity optical sensing for biological and chemical analyses in different field such as medical, environmental and food safety. The realization of an optimized sensing platform is closely related to the ability to finely control optical properties of nanostructures, which are, in turn, intimately linked to their geometrical and compositional characteristics. In this paper, an efficient and reproducible fabrication protocol, based on nanosphere lithography, for the realization of metal nanostructures with tunable plasmonic features is presented. In particular, the relationships between the geometric characteristics of different types of nanostructures with related optical phenomena such as enhanced absorption or extraordinary transmission are investigated in detail. These properties, together with electric field enhancement and confinement, are characterized and optimized in view of the employment of the fabricated nanostructures as optical transducers in nanoplasmonic chemosensor platforms working in the UV-VIS spectral range.