Andrey Vladimirovich Ivanov, Igor V. Bykov, Konstantin N. Afanas’ev, Andrey K. Sarychev
The electromagnetic field enhancement effect of a silver-plastic metasurface composed of a doubly periodic system of nanocavities is investigated. Localized plasmon modes are excited and manifest as pronounced local electric field maxima, spatially confined within the metasurface nanocavities where the silver surface layer has a minimal thickness. The frequency position of the excited plasmon resonances in the proposed metasurface strongly depends on the thickness of the silver coating and the uneven distribution of silver across the metasurface. The metasurface design enables the localization of individual biological objects (such as proteins, viral particles, extracellular vesicles, etc.) with characteristic sizes up to several hundred nanometers in the region of maximum metasurface field localization for effective Raman scattering enhancement.