Extracellular biosynthesis of cobalt ferrite nanoparticles by Monascus purpureus and their antioxidant, anticancer and antimicrobial activities: Yield enhancement by gamma irradiation.

Cobalt ferrite nanoparticles were successfully synthesized using the fungus Monascus purpureus ATCC16436 as a potentially low-cost, eco-friendly and easy to produce method. Fourier transform infrared spectroscopy confirmed the functional groups present in the prepared samples. X-ray diffraction pattern of the synthesized nanoparticles revealed a single-phase crystalline structure. Transmission electron microscope studies showed the spherical shape with a mean particle size of 6.50 nm. Vibrating sample magnetometer analyses revealed that the synthesized nanoparticles have a superparamagnetic behavior. In addition, the antioxidant, anticancer and antimicrobial activities of the synthesized nanoparticles were evaluated. The synthesized nanoparticles exhibited antioxidant potential as compared by ascorbic acid with 50% inhibitory concentration of 100.25 μg mL-1. Based on the MTT assay, the synthesized nanoparticles significantly inhibited the proliferation of two different human cancer cell lines (breast and liver) and normal human melanocytes. The recorded 50% inhibitory concentrations of the respective cell lines were 45.21, 61.86 and 200.15 μg mL-1. The synthesized nanoparticles showed potent antibacterial and antifungal activities against all the tested plant and human microbial pathogens with minimal inhibitory concentration range 250-500 μg mL-1. Moreover, the feasibility of production enhancement of the synthesized nanoparticles using the fungal culture as affected by gamma irradiation was also adopted. Gamma irradiation at 1000 Gy dramatically intensified the yield of nanoparticles to 24.87 g L-1. Accordingly, these findings suggest a new and alternate approach with the excellent biotechnological potentiality for the nanoparticles production that will open up the way for the industrial manufacture of nanomaterials.