Senna mediated facile green synthesis of nano ceria and its photo-catalytic and biological application. (2022) - Pavan Kumar, M.A.
Graphical abstract: Abstract: Multifunctional and bioactive cerium oxide nanoparticles (CeO2 Nps) were successfully synthesized by Solution Combustion Synthesis (SCS). Aqueous extract of Cassia angustifolia (Senna) was used as reducing agent for the green synthesis of Nps. The obtained Nps were characterized by powder X-Ray diffraction, Scanning Electron Microscopy (SEM) and UV–visible spectroscopic studies. XRD diffractions revealed the formation of pure cubic ceria phase with fluorite structure having crystallite sizes in the range of 10–50 nm. SEM studies indicate the formation of porous nanostructured materials. UV–visible spectrum exhibited characteristic absorption maximum at 318 nm. The Nps were subjected for evaluating the photo-catalytic degradation efficiency of carcinogenic dyes Methylene blue (MB) and Malachite green (MG). Comprehensive degradation of the MB and MG was observed in a span of 180 min and 160 min, respectively. The antioxidant activity of Npswas evaluated through the scavenging of 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) free radical. The Nps showed good antioxidant activity with IC50 value of 3142 µg/ml. Nps exhibited significant bactericidal activities on Klebsiellaaerogenes, Escherichia coli, Pseudomonas desmolyticum and Staphylococcus aureus . The antidiabetic potential of CeO2 -Nps was assessed and they exhibited excellent α-glucosidase (IC50 at 111.33 µg/ml) and α- amylase (IC 50 at 89.96 µg/ml) activity. The cytotoxic effects of CeO2 Nps were studied against MCF 7 (human breast cancer) cell line by MTT assay which showed dose dependent response. IC50 values were found to be 249 µg/ml demonstrating their higher cytotoxic efficacy. The study demonstrates a simple, economical and environment friendly method of Solution Combustion Synthesis that results in the preparation of multifunctional CeO2 Nps. The green synthesis of cerium oxide Nps employing aqueous extract of Cassia angustifolia is suggested as effective and substitute method for the hazardous chemical synthesis.