Mimicking Biogenic Silica Nanostructures Formation

Biomineralization processes are now fully recognized as inspiring systems for the design of new materials. In the case of silica, the formation of diatom shell or sponge spicule has attracted much attention in the last decade since it could provide key information to elaborate new hierarchically structured materials and nanodevices. In these two examples, the mineral phase is thought to be formed by the controlled assembly of nanoparticles generated in vivo from diluted precursor solutions, in the presence of biomolecular templates. The elucidation of biosilicification processes therefore relies on the understanding of biomolecules capacity to form and structure colloidal silica. Two different approaches have been developed. The first one starts with the extraction and identification of biomolecules present in silicifying organisms and then addresses the in vitro specific activity of these molecules towards silicon species. Alternatively, model macromolecules are used to understand the role of functionality and of structure on silica formation. This review aims at providing a critical overview of the most recent advances in these domains. Relevance for both the understanding of biosilicification process and the design of new bio-inspired nanomaterials are also discussed.