Biosynthesis of microrubble-shaped nanoporous Co3O4/rGO NCs using leaves extract of Neolamarckia cadamba and its antibacterial/antioxidant performance

Nowadays, the whole globe is paying great attention for the sustainable development, eco-friendly and economical production of nanostructures materials. With this motivation, the present work portrayed one-step ‘in-situ’ bioinspired green fabrication of Co3O4–reduced graphene oxide nanocomposites (Co3O4–rGO NCs) for the first time utilizing an aqueous leaf extract of Neolamarckia cadamba. As-fabricated NCs were characterized by several analytical and electron microscopic techniques viz. X-ray diffraction (XRD), Fourier Transform-Infrared (FT-IR), Energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), BET (Brunauer-Emmett-Teller), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) to evaluate their phases, structure, shape, composition, chemical state, porosity, optical and morphological aspects. The XRD study revealed a cubic spinel symmetry of NCs, while crystallite size estimated around 25 nm. TEM spectroscopy exposed an average particle size 8–10 nm of Co3O4 grown on the surface of reduced graphene oxide (rGO NCs), whereas SEM analysis showed sharped microrubble-shaped morphology. The formation of NCs by doping metal oxide with rGO through in-situ method were confirmed by XRD, EDS, Raman, and XPS spectroscopy. The BET study estimated the specific surface area and pore size of NCs as 98 m2/g and 8.9 nm respectively. The Co3O4–rGO NCs demonstrated an effective bactericidal activity against S. aureus, E. coli, K. pneumoniae, and B. subtillis. Prominently it was found that, a significant antibacterial activity seen against E. coli and S. aureus at a concentration 0.1 mg/100 µL may be due to scaffold morphology, nanoscale-structures and nanoporosity of the NCs. Due to receiving significant antibacterial activity, material’s molecular docking was assessed. Furthermore, an antioxidant activity of leaf extract and NCs was evaluated by DPPH method. An outstanding biological study of bioinspired NCs revealed that material could be used as a potent antimicrobial agent. [Display omitted] •Biosynthesized microrubble-shaped nanoporous Co3O4/rGO NCs using Neolamarckia cadamba.•Demonstrated a significant antibacterial performance of NCs against E. coli and S. aureus at concentration 0.1 mg/100 µL.•Neolamarckia cadamba exhibited a higher antioxidant efficiency as compared to NCs in both methanol and ethanol solvents.•Clinical findings revealed NCs could be a potent agent for microbial inhibition, while N. cadamba a good