Comparison of two-dimensional graphene oxide synthesis methods and biological activity evaluation

Graphene oxide 2D (two-dimensional) material, comprised of sp2 hybridized carbon atoms, and it has properties and applications in various fields such as medical, environmental and other industries. The aim of the present study is to synthesize Graphene Oxide using four different methods and characterize them by FTIR, CHN, XRD, Raman, SEM and EDS techniques. Finally, evaluated antibacterial activities of them. For this purpose to synthesize Graphene Oxide, four methods of modified Marcano (KMnO4, H2SO4/H3PO4), Hummers methods (KMnO4, NaNO3, H2SO4), modified Hummers (KMnO4, H2SO4) and the Brodie method (KMnO4, H2SO4, HNO3) were compared. As well as, antibacterial activities of all four methods were evaluated for gram-positive (S. aureus) and gram-negative (E. coli) bacteria by disk diffusion method. The results this research showed that Marcano’s method excluding the NaNO3, increasing the amount of KMnO4, and performing the reaction in a 9:1 mixture of H2SO4/H3PO4 improves the efficiency of the oxidation process. Marcano’s method provides a greater amount of hydrophilic oxidized graphene material as compared to Hummers’ method or two methods with additional KMnO4. The average size of Synthesis of Graphene Oxide with Marcano’s method was estimated by the Debye-Scherrer equation around 19.7 nm. The results of this research showed that Synthesized Graphene Oxide with four different methods did not have any antibacterial activities.