The ability to produce low-cost, hierarchically-structured and nanopatterned inorganic materials could potentially revolutionize the way we fabricate photovoltaic, energy storage, and optoelectronic devices. In nature, many organisms carry out the hierarchical assembly of metal oxide materials through cellular and biochemical processes that replicate periodic micro- and nanoscale features by a bottom-up approach at ambient conditions. For example, single-celled algae called diatoms produce a nanostructured amorphous silica skeleton called a frustule. The insertion of other metal oxide materials such as titanium or germanium dioxide into the nanostructure of the diatom frustule could potentially be utilized to fabricate new dye-sensitized solar cells, nanostructured battery electrodes, and electroluminescent display devices. The exploitation of diatom nanobiotechnology for the development of novel device concepts in these areas is overviewed.

In this paper, we described a new type of bioenabled nano-plasmonic sensors based on diatom photonic crystal biosilica with in-situ growth silver nanoparticles and demonstrated label-free chemical and biological sensing based on surface-enhanced Raman scattering (SERs) from complex samples. Diatoms are photosynthetic marine micro-organisms that create their own skeletal shells of hydrated amorphous silica, called frustules, which possess photonic crystal-like hierarchical micro- & nanoscale periodic pores. Our research shows that such hybrid plasmonic-biosilica nanostructures formed by cost-effective and eco-friendly bottom-up processes can achieve ultra-high limit of detection for medical applications, food sensing, water/air quality monitoring and geological/space research. The enhanced sensitivity comes from the optical coupling of the guided-mode resonance of the diatom frustules and the localized surface plasmons of the silver nanoparticles. Additionally, the nanoporous, ultra-hydrophilic diatom biosilica with large surface-to-volume ratio can concentrate more analyte molecules to the surface of the SERS substrates, which can help to detect biomolecules that cannot be easily adsorbed by metallic nanoparticles.

We demonstrate herein the fabrication of patterned layers of Zn₂SiO₄:Mn²⁺ and Y₂SiO₅:Eu³⁺ phosphor materials based on nanostructured diatom biosilicavia the inkjet printing process.