SCANNING TUNNELING MICROSCOPY OF FERRITIN NANOSTRUCTURES

In molecular electronics, components and circuits are made of biological molecules.1 It is important to study how the molecules arrange themselves on a substrate and to arrange them artificially. The ferritin molecule is a good candidate for making molecular devices. Previously, transmission electron microscopy was used to image only the metallic core of the ferritin molecule. We use scanning tunneling microscopy to study the behavior of ferritin deposited on a surface by imaging its protein shell. We have observed different kinds of ferritin aggregates as well as single molecules under different deposition conditions. For the first time ordered self-assemble of ferritin aggregates was observed. The aggregates were also found to be arranged in artificially made patterns. We suggest a possible mechanism of the formation of the observed structures.