National Research Council, Institute of Applied Sciences and Intelligent Systems "E. Caianiello", Unit of Naples, Via P. Castellino 111, 80131, Naples, Italy.
Department of Environmental, Biological, and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100, Caserta, Italy.
Sci Rep. 2024 Mar 18;14(1):6476. doi: 10.1038/s41598-024-56206-y.
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.
有序、准有序甚至无序的纳米结构可以被鉴定为几种原生动物、植物和动物的组成部分，这使得有效地操纵光进行种内和种间的通信、伪装或增强初级生产成为可能。硅藻是一种普遍存在的单细胞微藻，栖息在地球上所有的水生环境中。它们通过数千万年的进化，形成了超微结构的硅细胞壁，即壳，能够通过多种衍射、折射和波导过程来处理光学辐射，这可能是它们具有高效光合作用的基础。在这项研究中，我们采用了一系列成像、光谱和数值技术（包括传输成像、数字全息术、光致发光光谱学以及基于广角光束传播方法的数值模拟）来识别和描述 Pleurosigma strigosum 壳能够调节不同光谱内容的光学辐射的不同机制。最后，我们将壳的光学响应与在不同辐照处理下水生环境中活的单个细胞中与光的相互作用相关联。所得到的结果表明，与潜在有害的紫外线辐射相比，光合作用活性辐射在细胞内的传输更有利。
