Liquid‐Flowing Graphene Chip‐Based High‐Resolution Electron Microscopy

Abstract

The recent advances in liquid‐phase transmission electron microscopy represent tremendous potential in many different fields and exciting new opportunities. However, achieving both high‐resolution imaging and operando capabilities remain a significant challenge. This work suggests a novel in situ imaging platform of liquid‐flowing graphene chip TEM (LFGC‐TEM) equipped with graphene viewing windows and a liquid exchange system. The LFGCs are robust under high‐pressure gradients and rapid liquid circulation in ranges covering the experimental conditions accessible with conventional thick SiNx chips. LFGC‐TEM provides atomic resolution for colloidal nanoparticles and molecular‐level information limits for unstained wet biomolecules and cells that are comparable to the resolutions achievable with solid‐phase and cryogenic TEM, respectively. This imaging platform can provide an opportunity for live imaging of biological phenomena that is not yet achieved using any current methods.

Graphene Liquid Cell Electron Microscopy: Progress, Applications, and Perspectives

“…In another approach, Koo et al systematically presented liquid-flowing graphene chips (LFGCs). 77 As with similar configurations with conventional SiN x chips, the LFGCs consist of graphene-coated top and bottom chips with spacers for liquid channels (Figure 2I). The target liquid solution can be constantly supplied through opened channels.…”

“…(J) Electron micrographs of AuNP and bacterial cells acquired by LFGCs. Panels (I,J) were adapted with permission from ref . Copyright 2020 Wiley-VCH.…”

“…With the graphene top membrane and the SiN x bottom membrane, visualization of gold nanoparticle-free rotation in flowing liquid and the faceted crystallization of uranyl acetate is obtained. In another approach, Koo et al systematically presented liquid-flowing graphene chips (LFGCs) . As with similar configurations with conventional SiN x chips, the LFGCs consist of graphene-coated top and bottom chips with spacers for liquid channels (Figure I).…”

“…Overview of graphene liquid cell electron microscopy (GLC-EM). Recent progress of the GLC; fitst-generation veil-type GLC (adapted with permission from ref , copyright 2012 AAAS), second-generation well-type GLC (adapted with permission from ref , copyright 2016 Wiley-VCH, and ref , copyright 2018 American Chemical Society), and third-generation liquid-flowing GLC (adapted with permission from ref , copyright 2020 Wiley-VCH). The basic properties of the GLC (orange hexagon); atomic-scale resolution, chemical analysis, and radiation mitigation.…”

Effects of the Encapsulation Membrane in Operando Scanning Transmission Electron Microscopy

“…Although it can be technically challenging to incorporate 2D materials in the environmental flow chip because large defectfree transferring is required, recent work has used a graphene window liquid flow cell. 23 2D materials composed of lighter atoms, such as graphene and hexagonal boron nitride (hBN), can be also considered as membrane materials since they have been proven to possess superb impermeability for substances larger than protons, while introducing a negligible impact on image contrast. Yet, with a high-quality crystalline 2D material window, a strong diffraction signal, which would interfere with the image contrast, would introduce complicating effects.…”