Laboratoire de Physiques des Solides, UMR CNRS 8502, Bât. 510, 91405 Orsay, France.
Microsc Microanal. 2013 Aug;19(4):835-41. doi: 10.1017/S1431927613001724. Epub 2013 Jun 26.
Recombinant ferritin is an excellent template for the synthesis of magnetic nanoparticles. This paper describes carefully performed experiments both to identify ironoxides within nanoparticles and to measure the number of iron atoms in the cores of recombinant human H-chain ferritin (HFn), based on spectroscopy techniques. Using electron energy-loss spectroscopy (EELS) analysis, magnetite (Fe3O4) has been unequivocally identified as the ironoxide formed within HFn cores under special preparation conditions. Atom counting analysis by EELS and high-angle annular dark-field imaging further allowed the correlation of the particle sizes to the real Fe atom numbers in a quantitative manner. These results help clarify some structural confusion between magnetite and maghemite (γ-Fe2O3), and also provide standard data for the number of Fe atoms within Fe3O4 particles of a given size, whose use is not limited to cases of magnetite synthesized in the cores of recombinant human ferritin.
重组铁蛋白是合成磁性纳米颗粒的绝佳模板。本文详细描述了实验，旨在通过光谱技术确定纳米颗粒内的氧化铁，并基于光谱技术测量重组人 H 链铁蛋白 (HFn) 核内铁原子的数量。使用电子能量损失谱 (EELS) 分析，在特殊的制备条件下，明确鉴定出 HFn 核内形成的氧化铁为磁铁矿 (Fe3O4)。通过 EELS 和高角度环形暗场成像的原子计数分析，进一步以定量方式将颗粒尺寸与实际 Fe 原子数量相关联。这些结果有助于澄清磁铁矿和磁赤铁矿 (γ-Fe2O3) 之间的一些结构混淆，还为给定尺寸的 Fe3O4 颗粒内的 Fe 原子数量提供了标准数据，其用途不仅限于在重组人铁蛋白核内合成的磁铁矿的情况。
