Novel blade-like structure of reduced graphene oxide/α-Mn2O3 nanocomposite as an antimicrobial active agent against aerobic and anaerobic bacteria

Abstract

For the first time, we developed a novel nanocomposite of RGO decorated with α-Mn2O3 nanorods (NRs) for inhibiting microbially influenced corrosion. RGO sheets with 2 nm thick were effectively synthesized by the modified Hummers technique and then a hydrothermal reduction procedure. The fabricated RGO/α-Mn2O3 nanocomposite exhibited controlled morphology, geometry, surface exposure, and orientation. Single crystal α-Mn2O3 NRs with mean diameter of 50 nm and length of 1 μm were produced via the hydrothermal procedure to yield γ-manganite which was calcined at 700 °C. Stable RGO/α-Mn2O3 nanocomposite was successfully prepared via an efficient two-phase ultrasonication approach. The structures of the developed materials and nanocomposite were detected via different characterization techniques. Cost-effectiveness, long-term antimicrobial activity, and biocorrosion inhibition are the major advantages of the produced RGO/α-Mn2O3 nanocomposite. The nanocomposite's biocorrosion-protection was influenced by its high surface area and controlled size and morphology. Its antimicrobial mechanism against different anaerobic and aerobic microbial strains was deeply highlighted. Field emission SEM images showed that the blade-like RGO/α-Mn2O3 nanocomposite cruelly attached into the microbial cell walls forming morphology disruption, cell wrapping, and microbial killing. This nanocomposite exhibited ultrahigh potency against the anaerobic sulfate-reducing bacteria (SRB) strain Desulfovibrio halophilus SL 890 at 150 mg/L. Its highest potency against most of the tested aerobic strains was achieved at 2 μg/mL for Kocuria rhizophila EMCC 1246, Bacillus subtilis EMCCN 1152, Pseudomonas aeruginosa NRRL B-800, Staphylococcus aureus ATCC 25923, Aspergillus brasiliensis ATCC 9642, and Candida albicans ATCC 24433. The designed RGO/α-Mn2O3 nanocomposite provide a new platform for microbial growth inhibition.