[5p-S41-1~20] 7.2 Applications and technologies of electron beams

△ [5p-S41-6] TEM Observation of Proteins in Solution at Room Temperature with Graphene Sandwiched Structure

〇Yuki Sasaki^1,2, Tadahiro Kawasaki¹, Masanori Koshino², Chikara Sato², Kazutomo Suenaga² (1.JFCC, 2.AIST)

Keywords:TEM, Graphene, In-situ

It is important to reveal three dimensional structures of proteins with atomic resolution for drug design and development and for understanding how drugs work. Transmission electron microscopy (TEM) is one of the powerful tools to determine structures of nanomaterials. However, we cannot introduce proteins directly into the TEM chamber because TEM samples need to be put into vacuum. Therefore, we usually embedded proteins inside amorphous ice film. Although the amorphous ice can keep structures of proteins even under vacuum and electron beam irradiation conditions, the ice supporting layer with a thickness of a few hundred nanometers inhibits high-resolution observations of relatively small proteins having a diameter of 5 ~ 10 nm.In this work, we have applied a new technique to support proteins in a very thin water layer encapsulated inside two graphene sheets, and successfully observed a cage structure of a ferritin molecule, which is more difficult to be visualized so far comparing to a capsulated iron core.