Cryo-electron microscopy (Cryo-EM) is an important tool to understand biological mechanisms at molecular level. However, cryo-specimen preparation still remains many challenges. Biomolecules tend to be adsorbed to the air-water interface when applied onto canonical supporting films in cryo-EM, causing partial denaturation and/or preferential orientations. In this study, we developd a new type of cryo-EM supporting material using bioactive-ligand functionalized single-crystalline monolayer graphene membranes as supporting films. We have demonstrated that the functionalized graphene membrane (FGM) has the superior property of high conductivity and mechanical strength when irradiated in electron microscopy, and high affinity and selectivity on target biomolecules. These merits effectively facilitate to prevent biomolecules from touching air-water interface, and enable us to get a near-atomic resolution 3D reconstruction. We anticipate that the FGM grids could make it more reproducible and robust to perform cryo-EM specimens, therefore enhancing the efficiency and throughput of high-resolution cryo-EM structural determination.
Liu N, Zhang J, Chen Y*, Liu C, Zhang X, Xu K, Wen J, Luo Z, Chen S, Gao P, Jia K, Liu Z, Peng H, Wang HW*. (2019) Bioactive Functionalized Monolayer Graphene for High-Resolution Cryo-Electron Microscopy. J. Am. Chem. Soc. , 141:4016-4025 (*co-corresponding authors)