Exploring the Biomedical and Environmental Application of Silver Oxide Nanoparticles Derived From Citrus sinensis...

The use of agricultural waste offers an eco-friendly and sustainable way to synthesize functional nanomaterials. In this study, silver oxide nanoparticles (AgO-NPs) were synthesized by using peel extracts from Citrus deliciosa (CD) and Citrus nobilis (CN) through a green method. The bioactive compounds present in peel extracts act as natural reducing and stabilizing agents. UV-Visible spectroscopy showed a distinctive absorption peak in the range of 400-460 nm, confirming the successful formation of AgO-NPs. Dynamic Light Scattering analysis revealed that the AgO-NPs had hydrodynamic diameters between 14 to 55 nm. Scanning Electron Microscopy confirmed that the nanoparticles were mostly spherical. Fourier transform infrared spectroscopy identified functional groups on the nanoparticle surface. AgO-NPs derived from CD peel extract showed significant antibacterial properties, with inhibition zones ranging from 19 to 21 mm against Shigella dysenteriae, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. In antioxidant tests using the DPPH free radical scavenging assay, the CD-derived AgO-NPs achieved 65% inhibition at a concentration of 70 μg/mL, showing their strong ability to neutralize reactive oxygen species. Additionally, the α-amylase and α-glucosidase inhibition assays demonstrated notable in vitro enzyme inhibition by the AgO-NPs. Beyond their biomedical uses, the CD-derived AgO-NPs showed strong photocatalytic activity, achieving 73.51% degradation of methylene blue (MO) and 71% degradation of methyl orange (MO) when exposed to UV light. Together, these multifunctional properties highlight the usefulness of AgO-NPs made from citrus waste in both medical and environmental applications. Using fruit peel as a precursor not only adds value to agricultural waste but also supports circular economy efforts by promoting eco-friendly and sustainable development of nanomaterials.