From Diatom Biomolecules to Bioinspired Syntheses of Silica- and Titania-Based Materials

Amorphous silica is (next to CaCO3) the second most abundant biologically produced inorganic material. A certain group of photosynthetic microalgae, Galled diatoms, forms complex 3D silica architectures (frustules) containing regularly arranged nanoscale features (pores, channels, protuberances). Recently, biomolecules involved in diatom silica formation have been characterized, and first insights into their structure-function correlations have been obtained. This has spurred the development of synthetic (bio)polymers capable of directing the in vitro formation of silica and other inorganic materials from aqueous precursor solutions under mild conditions. Here we present a summary of current insight into the mechanism of silica formation by diatom biomolecules and provide examples of synthetic (bio)polymers for the formation of silica and titania materials with complex structures.