MAGNETOTUBE · 1D magnetic nanostructures using mineralizing peptides

Magnetite nanotubes are interesting for numerous applications including MRI, Biological and molecular separation, arsenic removal and catalysis of ammonia synthesis. The goal of this project is thus to create magnetic peptidic nanotubes using a bottom-up approach. A self-assembled peptidic nanotube template will be used to nucleate or attach magnetite nanoparticles on its inner and / or outer surface. The peptides will be selected for their ability to self-assemble in water and potential to mineralize magnetite or silica on their surface.The magnetite nanoparticles (Fe3O4) will be formed by oxydation of Fe(II) precursors onto the peptide surface or extracted from magnetotactic bacteria and bound onto the tube surface. We will also mineralize an additional silica layer in order to create triple-layered nanotubes (magnetite-peptide-silica or peptide-magnetite-silica) to improve the resilience and biocompatibility of these nanotubes. If necessary, the peptidic part will be removed through heating at high temperature (600°C). The resulting objects will be studied using SAXS, TEM, optical microscopy, Mössbauer spectroscopy.This study will help to gain insight on the biomineralization mechanisms used by magnetotactic bacteria to control the precipitation of magnetite chains in their cytoplasm.