Physiochemical and biological evaluation of stirrer- and autoclaved-based syntheses of cerium oxide nanoparticles using ginger (Zingiber officinale) extract

The purpose of this work was to examine the physiochemical and biological aspects of plant-mediated cerium oxide nanomaterials (CeO₂ NMs) using Zingiber officinale extract using stirring-based and autoclaved-based syntheses. X-ray diffraction analysis confirmed that the synthesized CeO₂ NMs exhibited the cubic fluorite crystal structure with the particle diameters of 3.73 nm (stirred) and 3.81 nm (autoclaved). Fourier transform infrared analysis confirmed the attachment of various functional groups that are covalently bonded to the CeO₂ NMs. Scanning electron microscopy images confirmed the spherical-agglomerated morphology of CeO₂ NMs. The assessment of the CeO₂ NM antioxidant properties using the radical scavenging assays showed a higher scavenging capacity of 34% and 43% for stirred-CeO₂ NMs, respectively. Similarly, stirred-CeO₂ NMs exhibited significant total antioxidant capacity (61 µgAAE/mg) and total reduction potential (52 µgAAE/mg) than autoclaved-CeO₂ NMs. Likewise, stirred-CeO₂ NM potential was determined to be higher for enzyme inhibitory activities (α-amylase, urease, and lipase) as compared to autoclaved-CeO₂ NMs. The significant peroxidase-like activity was depicted by stirred-CeO₂ NMs. Antibacterial activity of CeO₂ NMs and the ginger extract was found to be mild (7–7.5 mm zone of inhibition) against tested bacterial strains except for S. entertica, against which ginger extract showed a moderate zone of inhibition (9 mm). The study concludes that ginger extract can synthesize CeO₂ NMs following different synthetic modes. The presence of enough oxygen vacancies in stirred-CeO₂ NMs facilitates the enhanced shifting between Ce³⁺ and Ce⁴⁺ by interaction with hydrogen peroxide (H₂O₂), implying that nanomaterials hold promise for further exploration in biomedical applications.