Multiple Routes to Smart Nanostructured Materials from Diatom Microalgae: A Chemical Perspective

Abstract

Diatoms are unicellular photosynthetic microalgae, ubiquitously diffused in both marine and freshwater environments, which exist worldwide with more than 100 000 species, each with different morphologies and dimensions, but typically ranging from 10 to 200 µm. A special feature of diatoms is their production of siliceous micro- to nanoporous cell walls, the frustules, whose hierarchical organization of silica layers produces extraordinarily intricate pore patterns. Due to the high surface area, mechanical resistance, unique optical features, and biocompatibility, a number of applications of diatom frustules have been investigated in photonics, sensing, optoelectronics, biomedicine, and energy conversion and storage. Current progress in diatom-based nanotechnology relies primarily on the availability of various strategies to isolate frustules, retaining their morphological features, and modify their chemical composition for applications that are not restricted to those of the bare biosilica produced by diatoms. Chemical or biological methods that decorate, integrate, convert, or mimic diatoms' biosilica shells while preserving their structural features represent powerful tools in developing scalable, low-cost routes to a wide variety of nanostructured smart materials. Here, the different approaches to chemical modification as the basis for the description of applications relating to the different materials thus obtained are presented.

Microbe‐Mediated Extracellular and Intracellular Mineralization: Environmental, Industrial, and Biotechnological Applications

“…These modified frustules may be utilized for fabrication of dye‐sensitized solar cells, nanostructured battery electrodes, and electroluminescent display devices. [ 285 ]…”

Structural basis of light‐harvesting in the photosystem II core complex

“…Diatoms are marine organisms that evolved from red algae by secondary endosymbiosis and are responsible for ~40% of the net primary production (i.e., the formation of organic material from inorganic compounds minus the respiratory losses). They are characterized by a siliceous cell wall called frustule , which is an interesting topic in itself and has triggered research in biomimetic nanotechnology . In contrast to plants, diatoms incorporate Chl c in their peripheral antennae .…”

Solid-state NMR spectroscopic studies of 13C,15N,29Si-enriched biosilica from the marine diatom Cyclotella cryptica

“…[5][6][7][8][9][10] Apart from the identi cation of relevant biomolecules, the investigation of the formed mineral phases is interesting for materials science and technology. 11,12 Studying the organic-inorganic interface of diatom biosilica combines identi cation of tightly silica-associated biomolecules and determination of their spatial arrangement in the biomineral phase. Solid-state NMR spectroscopy is a powerful method for the investigation of biominerals.…”