“Outsourcing” Diatoms in Fabrication of Metal-Doped 3D Biosilica

Abstract

Diatoms have an ability that is unique among the unicellular photoautotrophic organisms to synthesize an intricately ornamented siliceous (biosilica) exoskeleton with an ordered, hierarchical, three-dimensional structure on a micro- to nanoscale. The unique morphological, structural, mechanical, transport, photonic, and optoelectronic properties of diatomaceous biosilica make it a desirable material for modern technologies. This review presents a summary and discussion of published research on the metabolic insertion of chemical elements with specific functional activity into diatomaceous biosilica. Included in the review is research on innovation in methods of synthesis of a new generation of functional siliceous materials, where the synthesis process is “outsourced” to intelligent microorganisms, referred to here as microtechnologists, by providing them with appropriate conditions and reagents.

A review on diatom biosilicification and their adaptive ability to uptake other metals into their frustules for potential application in bone repair

“…Other nongroup 2 metals have been successfully incorporated into diatom frustules, that include Nickel, Tin and Aluminium, which have been reviewed by other authors. 76 We propose that group 2 metals within the silica network of the frustule, like the calcium doping studies carried out by Leone et al and Li et al is of particular interested in biomedical engineering, particular bone tissue repair. Likewise, strontium and magnesium are of interest as they share similar chemistries and properties to magnesium, therefore whilst not guaranteed, it is highly likely that if diatoms can incorporate calcium then similar results could be expected with magnesium and strontium.…”

Physical, Chemical, and Genetic Techniques for Diatom Frustule Modification: Applications in Nanotechnology

“…The possibility to insert semiconducting or metallic elements in dielectric nanomaterials in order to modify their morphological, photo-and electro-luminescent properties is of great interest in several fileds, e.g., in sensing, optoelectronics, solar energy harvesting, catalysis, and biomedicine [29]. In this context, diatom cultures can be viewed as potential biofactories for massive bottom-up production of hierarchical, nanostructured hybrid materials.…”

Morphology and Mechanical Properties of Fossil Diatom Frustules from Genera of Ellerbeckia and Melosira

“…Diatoms are unicellular microorganisms with more than hundreds of thousands of species [ 8 ]. Their hard and porous wall with a unique 3D morphology is called diatom frustule [ 9 , 10 , 11 ]. Biosilica from diatom frustules resist disintegration and decay, and therefore, diatom-rich fossil deposits have formed over time at many sites (e.g., oceans, lakes and marshes) [ 12 , 13 ].…”

“…Furthermore, one of the most critical points for the application of fossil frustules in MMCs is to understand the exact intricate 3D morphologies of the frustules. SEM, also in combination with a focused ion beam (FIB), and AFM, were used to study the morphologies of the diatom frustules [ 9 , 10 , 28 , 29 , 31 , 32 ]. However, these techniques cannot access the interior structure nondestructively.…”