Bioreduction of iron nitrate hexahydrate by Roselle hibiscus fruit extract: applications

Plants are excellent specimen to encounter cytogenetic and mutagenic agents and they are widely employed in environmental monitoring studies. This study aims to synthesize iron oxide nanoparticles (IONPs) using Roselle hibiscus fruit extract through an environmentally acceptable and adopting commercially viable technique. The nature of synthesized IONPs was analysed by using UV–Vis, FT-IR, HR-TEM, EDX, Raman, SEM, XRD, and VSM. Crystalline structure, phase, and formation of IONPs have been confirmed by XRD. Further HR-TEM discloses the size of the particle as ~ 27 nm and its spherical morphological structure. FT-IR reports a sharp peak at 550 cm −1 which represents the Fe–O band vibration. SAED image shows the crystalline nature, with that EDS also indicating the presence of IONPs. However, the antioxidant activity of Roselle hibiscus fruit extract with various concentrations was studied using DPPH, hydroxyl, and nitric oxide radicals. The photo-catalytic behaviour of synthesized IONPs was evaluated by dye degradation of methylene blue. The complete degradation of the MB dye took 130 min. The antibacterial and antifungal activity of synthesized IONPs was examined and finally cytotoxicity was assessed by haemolytic activity. In addition to the above mention biological applications, Pb +2 and Cd +2 were recovered from wastewater. The percentage recovery of lead and cadmium ion was 91% at 300 min and 62% at 120 min, respectively. The equilibrium report of ion adsorption was recounted by Langmuir and Freundlich isotherm. Graphical abstract