ERA_Chemistry_Biomimetic formation and organization of magnetite nanoparticles

• Applicant: Dr. Damien Faivre
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 270108339

One-dimensional magnetic nanostructures have magnetic properties superior to non-organized materials due to a strong uniaxial shape anisotropy. Magnetosome chains in magnetotactic bacteria represent a biological paradigm of such a magnet, where magnetite crystals of controlled dimensions are synthesized in organelles called magnetosomes and are arranged into linear chains. The biological materials thus display a hierarchical architecture that is hardly matched by synthetic materials. In this project, we aim at applying the design principles used by the microorganisms to grow one-dimensional magnetic nanostructures along biological templates, using two different approaches.1) We will synthesize magnetic nanoparticles of controlled size in the beaker and then assemble these nanoparticles in linear chains. In particular, we will use biological additives that were shown in our labs to be powerful controllers of crystal dimensions in vitro to form a large amount of colloidally stable magnetite nanoparticles. The additive serves as a glue to assemble precursor nanoparticles that eventually form a mesocrystal. 2) We will utilize recombinantly expressed filamentous proteins with periodically repeated biological recognition sites that have either strong affinity to bind iron from solution or to attach to nanoparticles. The filament will thus serve as a template for the formation of magnetite nanofibers.We will use advanced high-resolution transmission electron microscopy (TEM) techniques, including cryo-TEM and electron holography, to characterize the nucleation and assembly process, as well as the magnetic properties of the products.This project will pave the way towards a better understanding of mesocrystal formation at the nanoscale. In addition, we anticipate that the outcomes of our research will be the starting points towards nano- and biomedical applications of 1D magnetic nanostructures.

• DFG Programme: Research Grants
• International Connection: Hungary
• Partner Organisation: OTKA Hungarian Scientific Research Fund
• Cooperation Partner: Professor Mihaly Posfai