Researchers at the Georgia Institute of Technology have developed a technique to study how unicellular micro-algae, known as diatoms, create their complex cell walls. Researchers hope to learn how diatoms assemble these nanometer-patterned, intricate micro-architectures to find better methods for creating nanomaterials in the laboratory.

Diatoms are natures most gifted nanotechnologists, said Nils Krger, an assistant professor in Georgia Techs School of Chemistry and Biochemistry and the School of Materials Science and Engineering. We want to learn how diatom cell walls are produced because human technology cant make something that intricate by self-assembly processes and under ambient conditions.

Diatoms are single-celled organisms that frequently appear as a brown, slippery coating on submerged stones and as phytoplankton in the open ocean. Tiny pores in the cell wall allow diatoms to exchange nutrients with the environment and remain at the surface of the water to absorb sunlight for photosynthesis. Diatom photosynthesis is responsible for 20 percent of the worlds organic carbon. The pores allow diatoms to be lightweight, but their cell wall gives them a strong mechanical structure. The strength of the cell wall comes from amorphous silica, or silicon dioxide (SiO2) -- virtually the same material as glass.

Diatom cell walls show an enormous diversity in form, most of them amazingly beautiful and ornate, depending on specific biomolecules produced by the diatom, Krger explained. Previous research has shown that uniquely modified proteins called silaffins and extremely long polyamine chains play a role in the structural design of the cell wall. Krger hypothesizes that the structure of the diatom silica critically depends on the type of silaffin present within the diatoms silica-producing organic matrix. Therefore, he expects that changing the silaffin equipment of a diatom cell should result in novel silica nanostructures.