Cerium oxide nanoparticles prepared through Bio-combustion using Ficus carica as effective antioxidant, anticancer and dye degrading agent
Sanjay S. Majani, Pallavi Singh, Pallavi Kumari, Poojitha B. Sridhara Setty, Chandan Shivamallu, Chandrashekar Srinivasa, Kasim Sakran Abass, Muzaffar Iqbal, Raghavendra G. Amachawadi, Victor Stupin, Ekaterina Silina, Shiva Prasad Kollur
Abstract
The rising levels of environmental contamination and oxidative stress disorders have led to a growing demand for multifunctional nanomaterials that possess both biomedical and catalytic importance. CeO 2 nanoparticles (NPs) were synthesized using a green solution combustion method involving Ficus carica F. extract, followed by an evaluation of their structural, biological, and photocatalytic properties. XRD confirmed a pure cubic fluorite phase (Fm-3m) with a crystallite size of 11.3 nm, which was also validated through Williamson–Hall and Rietveld refinements (χ 2 = 1.9). FTIR spectroscopy revealed strong Ce–O vibrational modes at 955 cm −1 , and a bandgap of 3.03 eV was determined through DRS. The SEM/TEM images displayed spherical, agglomerated particles with an average diameter of 13.5 nm. The BET analysis revealed a surface area of 30.081 m 2 /g, a pore radius of 1.374 nm, and a pore volume of 0.057 cm 3 /g, confirming the presence of microporosity. The analysis via XPS validated the existence of Ce, O, and C, revealing the coexistence of Ce 3+ /Ce 4+ oxidation states alongside surface hydroxyl species. CeO 2 NPs exhibited a dose-dependent redox activity that resulted in a reduction of cell viability to 48.82% at a concentration of 50 µM. H 2 O 2 enhanced LDH release to 223.86%, whereas CeO 2 NPs (1–7.5 µM) reduced it to 124.84%, demonstrating redox cycling antioxidant protection. Fluorescence imaging showed dose-dependent duality—antioxidant at low, pro-oxidant at high—consistent with mitochondrial damage and ATP depletion. Furthermore, CeO 2 NPs demonstrated a remarkable 94.9% degradation of methylene blue under visible light, indicating their significant potential for both therapeutic and environmental applications.