Bio-Inspired Graphene Nanomaterials: Synthesis and Characterization for Ambient Microbial Destruction

This study explores the conversion of carbon-rich coconut waste into bio-inspired graphene oxide (GO) and reduced graphene oxide (rGO) for application as antimicrobial agents, addressing air quality and public health concerns. Both GO and rGO demonstrated significant antimicrobial properties against a variety of airborne microorganisms. GO achieved nearly complete inhibition of bacteria, such as Staphylococcus spp., and fungi, including Aspergillus spp., at low concentrations. Similarly, rGO effectively inhibited Escherichia coli and Brucella spp., highlighting its broad-spectrum antimicrobial activity. The synthesis of GO was performed using an enhanced Hummers' method, producing nanomaterials with distinct surface functionalities, which were characterized by X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). XRD analysis revealed a notable shift from the sharp graphite peak at 2θ = 26.4°, indicating the (002) plane, to a broadened peak at 2θ = 11.15° in GO, signifying successful oxidation and exfoliation of graphite. For rGO, the disappearance of the 11.15° peak confirmed the partial restoration of graphitic structure. FESEM imaging displayed the nanosheet morphology of GO and rGO, along with microscopic analysis revealing the physical interaction of GO with bacterial and fungal cells, enabling precise identification of microorganisms. Moreover, the GO-coated surfaces exhibited higher surface roughness, promoting bacterial adhesion, which underscores the critical role of surface properties in antimicrobial efficacy. This research contributes to the Sustainable Development Goals (SDG 3: Good Health and Well-being, and SDG 11: Sustainable Cities and Communities) by providing an eco-friendly solution for mitigating microbial pollution in the ambient environment through the use of bio-based nanomaterials.