Hydrophilic, Clean Graphene for Cell Culture and Cryo-EM Imaging

Mitigating Contamination with Nanostructure-Enabled Ultraclean Storage

Airborne hydrocarbon contamination hinders nanomanufacturing, limits characterization techniques, and generates controversies regarding fundamental studies of advanced materials; consequently, we urgently need effective and scalable clean storage techniques. In this work, we propose an approach to clean storage using an ultraclean nanotextured storage medium as a getter. Experiments show that our proposed approach can maintain surface cleanliness for more than 1 week and can even passively clean initially contaminated samples during storage. We theoretically analyzed the contaminant adsorption-desorption process with different values of storage medium surface roughness, and our model predictions showed good agreement with experiments for smooth, nanotextured, and hierarchically textured surfaces, providing guidelines for the design of future clean storage systems. The proposed strategy offers a promising approach for portable and cost-effective storage systems that minimize hydrocarbon contamination in applications requiring clean surfaces, including nanofabrication, device storage and transportation, and advanced metrology.

Vacancy designed 2D materials for electrodes in energy storage devices

Vacancies are ubiquitous in nature, usually playing an important role in determining how a material behaves, both physically and chemically. As a consequence, researchers have introduced oxygen, sulphur and other vacancies into bi-dimensional (2D) materials, with the aim of achieving high performance electrodes for electrochemical energy storage. In this article, we focused on the recent advances in vacancy engineering of 2D materials for energy storage applications (supercapacitors and secondary batteries). Vacancy defects can effectively modify the electronic characteristics of 2D materials, enhancing the charge-transfer processes/reactions. These atomic-scale defects can also serve as extra host sites for inserted protons or small cations, allowing easier ion diffusion during their operation as electrodes in supercapacitors and secondary batteries. From the viewpoint of materials science, this article summarises recent developments in the exploitation of vacancies (which are surface defects, for these materials), including various defect creation approaches and cutting-edge techniques for detection of vacancies. The crucial role of defects for improvement in the energy storage performance of 2D electrode materials in electrochemical devices has also been highlighted.

Cryo-EM samples of gas-phase purified protein assemblies using native electrospray ion-beam deposition

An increasing number of studies on biomolecular function indirectly combine mass spectrometry (MS) with imaging techniques such as cryo electron microscopy (cryo-EM). This approach allows information on the homogeneity, stoichiometry, shape, and interactions of native protein complexes to be obtained, complementary to high-resolution protein structures. We have recently demonstrated TEM sample preparation via native electrospray ion-beam deposition (ES-IBD) as a direct link between native MS and cryo-EM. This workflow forms a potential new route to the reliable preparation of homogeneous cryo-EM samples and a better understanding of the relation between native solution-phase and native-like gas-phase structures. However, many aspects of the workflow need to be understood and optimized to obtain performance comparable to that of state-of-the-art cryo-EM. Here, we expand on the previous discussion of key factors by probing the effects of substrate type and deposition energy. We present and discuss micrographs from native ES-IBD samples with amorphous carbon, graphene, and graphene oxide, as well as landing energies in the range between 2 and 150 eV per charge.