Metal oxide nanoparticle isolation formed intracellularly through bio-mineralisation and their microstructural investigation by electron microscopy.

The applicant will isolate nanoparticles formed in bacterial cells through metal bio-mineralisation processes inside cage-shaped, nano-scale protein structures called encapsulins.
The production, composition and properties of the formed metal oxide nanoparticles will be studied as function of cell environmental variables such as temperature, time, media composition and presence of metals. Various metal salts will be added to the growth medium of the bacterium before encapsulin assembly is induced through starvation or antibiotic treatment.
Then the microstructural, chemical, electrical and magnetic properties of the isolated metal oxide nanoparticles will be investigated using electron microscopic and spectroscopic methods with nm-scale spatial resolution. In particular, we will study the microstructure and crystallography of the iron oxide nanoparticles by high-resolution electron microscopy. Energy-dispersive X-ray spectroscopy and X-ray mapping will be used to investigate the chemical composition and homogeneity of the particles, while electron energy-loss spectroscopy will be used to determine the electronic and chemical properties, in particular the valence of the transition metal ions.