We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.

This review highlights the potential of Kelvin probe force microscopy (KPFM) beyond imaging to simultaneously study structural and electronic properties of functional surfaces and interfaces. This is of paramount importance since it is well established that a solid surface possesses different properties than the bulk material. The versatility of the technique allows one to carry out investigations in a non‐invasive way for different environmental conditions and sample types with resolutions of a few nanometers and some millivolts. KPFM can be used to acquire a wide knowledge of the overall electronic and electrical behavior of a sample surface. Moreover, by KPFM it is possible to study complex electronic phenomena in supramolecular engineered systems and devices. The combination of such a methodology with external stimuli, e.g., light irradiation, opens new doors to the exploration of processes occurring in nature or in artificial complex architectures. Therefore, KPFM is an extremely powerful technique that permits the unraveling of electronic (dynamic) properties of materials, enabling the optimization of the design and performance of new devices based on organic‐semiconductor nanoarchitectures.

Electrically conductive composites comprising polymers and graphene are extremely versatile and have a wide range of potential applications. The conductivity of these composites depends on the choice of polymer matrix, the type of graphene filler, the processing methodology, and any post-production treatments. In this review, we discuss the progress in graphene–polymer composites for electrical applications. Graphene filler types are reviewed, the progress in modelling these composites is outlined, the current optimal composites are presented, and the example of strain sensors is used to demonstrate their application.

Understanding human health risk associated with the rapidly emerging graphene-based nanomaterials represents a great challenge because of the diversity of applications and the wide range of possible ways of exposure to this type of materials. Herein, the biodegradation of graphene oxide (GO) sheets is reported by using myeloperoxidase (hMPO) derived from human neutrophils in the presence of a low concentration of hydrogen peroxide. The degradation capability of the enzyme on three different GO samples containing different degree of oxidation on their graphenic lattice, leading to a variable dispersibility in aqueous media is compared. hMPO fails in degrading the most aggregated GO, but succeeds to completely metabolize highly dispersed GO samples. The spectroscopy and microscopy analyses provide unambiguous evidence for the key roles played by hydrophilicity, negative surface charge, and colloidal stability of the aqueous GO in their biodegradation by hMPO catalysis.

We present a novel approach for detecting and visualizing graphene oxide (GO) with high contrast on different substrates, including glass, quartz, and silicon. Visualization of GO sheets is accomplished through quenching the fluorescence of a thiophene dye, giving high optical contrast without the need to use interference methods. A comparison of fluorescence, AFM, and XRD measurements confirmed that even a single GO sheet can completely quench the fluorescence and thus be quickly visualized.

The tuning of the molecular material work-function via strong coupling with vacuum electromagnetic fields is demonstrated. Kelvin probe microscopy extracts the surface potential (SP) changes of a photochromic molecular film on plasmonic hole arrays and inside Fabry-Perot cavities. Modulating the optical cavity resonance or the photochromic film effectively tunes the work-function, suggesting a new tool for tailoring material properties.

The different exfoliation routes of graphite to produce graphene by sonication in solvent, chemical oxidation and electrochemical oxidation are compared. The exfoliation process and roughening of a flat graphite substrate is directly visualized at the nanoscale by scanning probe and electron microscopy. The etching damage in graphite and the properties of the exfoliated sheets are compared by Raman spectroscopy and X‐ray diffraction analysis. The results show the trade‐off between exfoliation speed and preservation of graphene quality. A key step to achieve efficient exfoliation is to couple gas production and mechanical exfoliation on a macroscale with non‐covalent exfoliation and preservation of graphene properties on a molecular scale.

Graphene oxide (GO) is attracting an ever-growing interest in different fields and applications. Not much is known about the possible impact of GO sheet lateral dimensions on their effects in vitro, especially on human primary cells. In an attempt to address this issue, we present a study to evaluate, how highly soluble 2-dimensional GO constituted of large or small flakes affects human monocyte derived macrophages (hMDM). For this purpose, the lateral size of GO was tuned using sonication and three samples were obtained. The non sonicated one presented large flakes (~1.32 μm) while sonication for 2 and 26 hours generated small (~0.27 μm) and very small (~0.13 μm) sheets of GO, respectively. Cell studies were then conducted to evaluate the cytotoxicity, the oxidative stress induction, the activation potential and the pro-inflammatory effects of these different types of GO at increasing concentrations. In comparison, the same experiments were run on murine intraperitoneal macrophages (mIPM). The interaction between GO and cells was further examined by TEM and Raman spectroscopy. Our data revealed that the GO sheet size had a significant impact on different cellular parameters (i.e. cellular viability, ROS generation, and cellular activation). Indeed, the more the lateral dimensions of GO were reduced, the higher were the cellular internalization and the effects on cellular functionality. Our data also revealed a particular interaction of GO flakes with the cellular membrane. In fact, a GO mask due to the parallel arrangement of the graphene sheets on the cellular surface was observed. Considering the mask effect, we have hypothesized that this particular contact between GO sheets and the cell membrane could either promote their internalization or isolate cells from their environment, thus possibly accounting for the following impact on cellular parameters.