Overall, our method has proven to provide an aqueous dispersion of highly dispersible GO flakes, which are non-pyrogenic and chemically stable in water at room temperature for more than 6 months . The maintenance of the surface chemistry is of utmost importance, especially considering that the degree of oxidation also plays a role in the biocompatibility of GO . Reduced GO may agglomerate to a greater extent in physiological milieu, which can affect the rate and extent to which they are cleared from the body . Therefore, maintaining the surface chemistry within stringent standards enables the assessment of the biological impact of the structural properties of GBMs such as lateral dimensions and thickness. Finally, the importance of using non-pyrogenic materials for the analysis of biological interactions of 2D materials should not be ignored. Regulatory authorities have fixed a limit for endotoxin contamination in order for any material to be used in the clinic . Using a cell-based assay (Figure , Supporting Information), we showed that all three GO materials produced in the present work met the non-pyrogenic criteria for the biomedical application and hazard assessment of these materials .