Graphene oxide (GO) is a prominent GBM, which can be easily produced by oxidation and exfoliation of graphite under acidic conditions. This exfoliation of graphite yields graphene flakes that are decorated with a large amount of oxygen functional groups including epoxides, hydroxyls and carboxyls . Due to this specific surface chemistry, GO flakes present interesting features for biological and biomedical applications, including both a high colloidal stability in physiological milieu compared to pristine graphene, and an extremely high surface area-to-volume ratio that enables interactions with a wide range of molecules . GO can also be chemically modified in numerous ways, providing an attractive playground for medicinal chemists to anchor a variety of therapeutic molecules or imaging probes for biomedical purposes, or to tune the biological properties of GBMs themselves . Together with its favourable size-dependent pharmacokinetics and urinary excretion and its biocompatibility , GO has raised considerable interest in nanomedicine for its use as nanovector . However, there are still concerns regarding the safety of GO and other GBMs. These concerns have been met with numerous but unfortunately contradictory reports on the materials' biological impact . Such confounding information has hindered the comparison between nanosafety studies, due to an insufficient physicochemical characterisation of the tested GBMs . A detailed characterisation methodology is highly desired to establish correlations between specific properties of GBMs (such as lateral dimensions and surface chemistry) and their biological activity. A better understanding of this relationship would ultimately facilitate the predictions of their potential health risks and allow for more informed decisions to be made regarding the translation of these materials from the lab bench to the clinic . In order to establish such correlations, GBMs with controlled physicochemical properties should be synthesised so individual variables can be tested. Moreover, the development of facile production methods of non-pyrogenic GBMs (especially GO) with reproducible, high-standard dimensional features, defined functionalisation degree, and high chemical purity represents a key endeavour for their use in nanomedicine and hazard assessment studies.