Graphene‐Enhanced 3D Chemical Mapping of Biological Specimens at Near‐Atomic Resolution

The direct imaging of individual atoms within the cellular context holds great potential for understanding the fundamental physical and chemical processes in organisms. Here, a novel approach for imaging of electrically insulated biological cells by introducing a graphene encapsulation approach to “disguise” the low‐conductivity barrier is reported. Upon successful coating using a water‐membrane‐based protocol, the electrical properties of the graphene enable voltage pulsing field evaporation for atom probe tomography (APT). Low conductive specimens prepared from both Au nanoparticles and antibiotic‐resistant bacterial cells have been tested. For the first time, a significant graphene‐enhanced APT mass resolving power is also observed confirming the improved compositional accuracy of the 3D data. The introduction of 2D materials encapsulation lays the foundation for a breakthrough direction in specimen preparation from nanomembrane and nanoscale biological architectures for subsequent 3D near‐atomic characterization. Direct imaging of individual atoms within biological specimens holds great potential for understanding the fundamental physical and chemical processes in organisms. Successful imaging of electrically insulated biological cells in atom probe tomography (APT) is achieved by introducing a graphene encapsulation approach to “disguise” the low‐conductivity barrier. A significant graphene‐enhanced APT mass resolving power is observed confirming the improved compositional accuracy.