Pleurosigma strigosum diatom frustule as a natural, multi-functional photonic platform

¹ National Research Council, Institute of Applied Sciences and Intelligent Systems “Eduardo Caianiello”, Unit of Naples, Via P. Castellino 111, 80131 Naples, Italy
² Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, 405 30 Gteborg, Sweden
³ University of Belgrade, Department of Ecology, Institute for Biological Research “Sinisa Stankovic”, Bulevar despota Stefana 142, 11060 Belgrade, Serbia

^* e-mail: edoardo.detommasi@cnr.it

Published online: 31 October 2024

Abstract

Nature provides various organisms with ordered or quasi-ordered dielectric nanostructures that enable several animals, plants, and protists to manipulate light, optimizing inter- and intra-species communication, camouflage, or solar light harvesting. In particular, diatom microalgae possess nanostructured silica cell walls, known as frustules, which efficiently interact with optical radiation through multiple diffractive, refractive, scattering, waveguiding, and frequency down-conversion mechanisms. These properties contribute to diatoms’ efficiency in photosynthesis, UV tolerance, and possibly influence the phototaxis mechanisms of motile species. In our study, we utilized several imaging, spectroscopic, and numerical techniques to explore the optical functionalities of individual frustule components in the pennate, motile diatom Pleurosigma strigosum. We discuss the implications of frustule photonic properties on the living cell, and envision the exploitation of these properties in multifunctional, bio-derived photonic devices.