Fig. (a) demonstrates the schematic of the process used for the functionalized graphene production. Dry yeast cells were inoculated with graphite powder suspension in glucose solution at room temperature. The solution in the flask turned dark and turbid after one week when visually inspected, as seen in Fig. ). On the other hand, no visible differences were noticed in the reference yeast glucose mixture without graphite and also the reference glucose graphite mixture solution without the yeast (Fig. ). The appearance of dark colloidal dispersion when yeast and graphite simultaneously present in glucose solution suggests exfoliation of graphite. As supporting evidence of exfoliation, we anchored thin graphite layers by mechanical exfoliation to an Si/SiO2 (290nm) samples. As seen in Fig. ), a few layer graphene (~10 layers, measured by optical contrast) was successfully seen to be delaminated when immersed inside yeast-glucose solution for 1 week. To further characterise the exfoliation of graphite in yeast-glucose dispersions, the samples were subjected to a differential centrifugation process to remove yeast, and thick graphite flakes (details given in Method section). The obtained suspensions were drop-casted on Si substrates for all further characterization. The AFM micrograph, Fig. , showed the uniform distribution of graphene flakes where the thickness profile of the prepared layers, as obtained from the micrograph and histogram, revealed the thickness to be ~10 nm, thereby suggesting the exfoliation of bulk graphite. In order to further characterise the exfoliated graphene samples, Raman and TEM analyses were performed. The obtained Raman spectra, Fig. (e), suggested the exfoliation of yeast-treated graphite as indicated by the peak at 1350 cm -1 and ~ 2700 cm -1 corresponding to D and 2D bands of few-layer graphene, respectively. The finite D peak for the yeast treated precursor is owed to the functionalization of prepared sheets due to functional groups introduced during yeast mediated exfoliation. The 2D band at 2700 cm -1 , on the other hand, corresponds to the number of layers in the graphene and intensifies with decreasing number of layers. The TEM micrograph, Fig. (f), of the graphene suspension further demonstrated the presence of a few layer graphene flake in the dispersion. The exfoliation mechanism was studied using microscopic techniques including AFM and SEM, given in supplementary Fig. and. The SEM micrographs suggested the yeast cells' attachment to the carbon layers where the shearing and tearing of the sheets was mediated by the growth and reproduction of the attached cells which occurs asexually through budding in case of Saccharomyces cerevisiae. The separation of a daughter cell from the mother cell is hypothesised to result in layers dissociation and the formation of few-layer graphene structures.