RESUMO
A simple, eco-friendly, green routine co-precipitation method was experimented to synthesize iron nanoparticles (Fe-NPs) using the cell-free supernatant of actinobacteria. The biosynthesized nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffractometer (XRD), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential analyser and Fourier transform infrared (FTIR) spectroscopy. The synthesized nanoparticles were crystalline, quasi-spherical in shape and their average size ranged from 65.0 to 86.7 nm. In our radical scavenging assays, the nanoparticles have revealed a strong antioxidant activity with respective standard ascorbic acid. The nanoparticles also exhibited a wide bactericidal action on pathogens namely Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Shigella flexneri and Escherichia coli. At 75 µg/ml concentration, the nanoparticles showed the highest inhibition against S. aureus (16.2 ± 0.45 mm), the lowest zone of inhibition was seen against K. pneumoniae (12.3 ± 0.50 mm) and moderate inhibition on other strains. Further, its cytotoxicity was seen as effective against DU145 and PC3 cells. The morphological changes caused in the prostate cell lines due to antiproliferative effect were observed through DAPI and AO/EB staining. This synthesis method specifies a new route for biosynthesis of Fe-NPs and the accomplished results illustrates that it can be used for a wide range of biomedical applications.
