Diatom biosilica in plasmonics: applications in sensing, diagnostics and therapeutics [Invited]

Several living organisms are able to synthesize complex nanostructures providedwith peculiar physical and chemical properties by means of finely-tuned, genetically controlledbiomineralization processes. Frustules, in particular, are micro- and nano-structured silica shellsproduced by ubiquitous diatom microalgae, whose optical properties have been recently exploitedin photonics, solar energy harvesting, and biosensing. Metallization of diatom biosilica, both inthe shape of intact frustules or diatomite particles, can trigger plasmonic effects that in turn canfind application in high-sensitive detection platforms, allowing to obtain effective nanosensorsat low cost and on a large scale. The aim of the present review article is to provide a wide,complete overview on the main metallization techniques applied to diatom biosilica and on theprincipal applications of diatom-based plasmonic devices mainly but not exclusively in the fieldsof biochemical sensing, diagnostics and therapeutics. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement