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

申请人将分离细菌细胞中通过金属生物矿化过程形成的纳米颗粒，这些纳米颗粒被称为胶囊状的纳米级蛋白质结构。形成的金属氧化物纳米颗粒的生产、组成和性能将作为细胞环境变量（如温度、时间、介质组成和金属的存在）的函数进行研究。在通过饥饿或抗生素治疗诱导包封组装之前，将各种金属盐添加到细菌的生长培养基中。然后利用纳米尺度空间分辨率的电子显微镜和光谱学方法研究分离的金属氧化物纳米颗粒的微观结构、化学、电学和磁性能。特别是，我们将通过高分辨率电子显微镜研究氧化铁纳米颗粒的微观结构和晶体学。能量色散x射线光谱和x射线测绘将用于研究粒子的化学组成和均匀性，而电子能量损失光谱将用于确定电子和化学性质，特别是过渡金属离子的价电子。

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.