Cobalt nanoparticles synthesizing potential of orange peel aqueous extract and their antimicrobial and antioxidant activity

The ability of cobalt nanoparticles (CoNPs) to absorb electromagnetic waves led to their use as potential biomedical agents in recent years. The properties of magnetic fluid containing cobalt nanoparticles are extraordinary. Hence, this research was designed to evaluate the Co(NO3)2 reducing the potential of orange peel aqueous extract and assessed their antimicrobial and antioxidant activities. The aqueous extract derived from orange peel had the potential to fabricate the CoNPs from 1 M Co(NO3)2 and the synthesized CoNPs were successfully characterized by standard nanoparticles characterization techniques such as UV-vis spectropho-tometer, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Dynamic light scattering (DLS) analyses. The FTIR analysis revealed that the synthesized CoNPs were capped with active functional groups. It was characterized by predominant peaks corresponding to carbonyl (C--O), amide (CO = ), and C-O of alcohols or phenols. The size and shape of CoNPs were found as 14.2-22.7 nm and octahedral, respectively, under SEM analysis. Furthermore, at increased concentration, the CoNPs demonstrated remarkable antimicrobial activity against common bacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae) and fungal (Aspergillus niger) pathogens. Furthermore, these CoNPs also showed consid-erable in-vitro antioxidant activities against various free articles such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Hydrogen Peroxide (H2O2). These results suggest that OP aqueous extract synthesized CoNPs possess considerable biomedical applications.