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De Tommasi E, Rea I, Ferrara MA, De Stefano L, De Stefano M, Al-Handal AY, Stamenković M, Wulff A. Multiple-pathways light modulation in Pleurosigma strigosum bi-raphid diatom. Sci Rep 2024; 14:6476. [PMID: 38499606 PMCID: PMC10948915 DOI: 10.1038/s41598-024-56206-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 03/04/2024] [Indexed: 03/20/2024] Open
Abstract
Ordered, quasi-ordered, and even disordered nanostructures can be identified as constituent components of several protists, plants and animals, making possible an efficient manipulation of light for intra- and inter- species communication, camouflage, or for the enhancement of primary production. Diatoms are ubiquitous unicellular microalgae inhabiting all the aquatic environments on Earth. They developed, through tens of millions of years of evolution, ultrastructured silica cell walls, the frustules, able to handle optical radiation through multiple diffractive, refractive, and wave-guiding processes, possibly at the basis of their high photosynthetic efficiency. In this study, we employed a range of imaging, spectroscopic and numerical techniques (including transmission imaging, digital holography, photoluminescence spectroscopy, and numerical simulations based on wide-angle beam propagation method) to identify and describe different mechanisms by which Pleurosigma strigosum frustules can modulate optical radiation of different spectral content. Finally, we correlated the optical response of the frustule to the interaction with light in living, individual cells within their aquatic environment following various irradiation treatments. The obtained results demonstrate the favorable transmission of photosynthetic active radiation inside the cell compared to potentially detrimental ultraviolet radiation.
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Affiliation(s)
- Edoardo De Tommasi
- National Research Council, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Unit of Naples, Via P. Castellino 111, 80131, Naples, Italy.
| | - Ilaria Rea
- National Research Council, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Unit of Naples, Via P. Castellino 111, 80131, Naples, Italy
| | - Maria Antonietta Ferrara
- National Research Council, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Unit of Naples, Via P. Castellino 111, 80131, Naples, Italy
| | - Luca De Stefano
- National Research Council, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Unit of Naples, Via P. Castellino 111, 80131, Naples, Italy
| | - Mario De Stefano
- Department of Environmental, Biological, and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100, Caserta, Italy
| | - Adil Y Al-Handal
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, 405 30, Göteborg, Sweden
| | - Marija Stamenković
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, 405 30, Göteborg, Sweden
- Department of Ecology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Angela Wulff
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, 405 30, Göteborg, Sweden.
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Gilic M, Ghobara M, Reissig L. Tuning SERS Signal via Substrate Structuring: Valves of Different Diatom Species with Ultrathin Gold Coating. Nanomaterials (Basel) 2023; 13:nano13101594. [PMID: 37242011 DOI: 10.3390/nano13101594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/04/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023]
Abstract
The discovered light modulation capabilities of diatom silicious valves make them an excellent toolkit for photonic devices and applications. In this work, a reproducible surface-enhanced Raman scattering (SERS) enhancement was achieved with hybrid substrates employing diatom silica valves coated with an ultrathin uniform gold film. Three structurally different hybrid substrates, based on the valves of three dissimilar diatom species, have been compared to elucidate the structural contribution to SERS enhancement. The comparative analysis of obtained results showed that substrates containing cylindrical Aulacoseira sp. valves achieved the highest enhancement, up to 14-fold. Numerical analysis based on the frequency domain finite element method was carried out to supplement the experimental results. Our results demonstrate that diatom valves of different shapes can enhance the SERS signal, offering a toolbox for SERS-based sensors, where the magnitude of the enhancement depends on valve geometry and ultrastructure.
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Affiliation(s)
- Martina Gilic
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Mohamed Ghobara
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Louisa Reissig
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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