As graphene technologies progress to commercialization and large-scale manufacturing, issues of material and processing safety will need to be more seriously considered. The single word “graphene” actually represents a family of related materials with large variations in number of layers, surface area, lateral dimensions, stiffness, and surface chemistry. Many of these materials have aerodynamic diameters below 5 μm and can potentially be inhaled into the human lung. Graphene materials show several unique modes of interaction with biological molecules, tissues, and cells. The limited literature suggests that graphene materials can be either benign or harmful and that the biological response varies according to a material’s physicochemical properties and biologically effective dose. The present article reviews the current literature on the graphene–biological interface with an emphasis on the mechanisms and fundamental biological responses relevant to material safety and also to potential biomedical applications

This article reviews the use of scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) to characterize the physical and electronic properties of epitaxial graphene. Topographical variations revealed by STM allow the determination of the number of graphene layers and the detection of lattice mismatch between the graphene and the substrate, as well as rotational disorder. STS allows the local electronic characterization of graphene. STM/STS can also be used to perform local studies of graphene modification through processes such as atomic/molecular adsorption and intercalation.