Oxalis pes-caprae L. Extract Conferred Its Biological Activities to Silver Nanoparticles

This study used Oxalis pes-caprae L. (OP) to develop a low-budget, low-maintenance, and environment-friendly production method for silver nanoparticles (AgNPs) and evaluated their antibacterial, antifungal, and antioxidant abilities. Ultraviolet–visible (UV–Vis) spectroscopy results revealed a maximum of absorbance at 431 nm, confirming the formation of AgNPs. Moreover, Fourier transform infrared spectroscopy (FTIR) analysis of synthesized AgNPs indicated the presence of various important functional groups, such as O–H, CH, H–C–H, and C–O–C, which are involved in the synthesis and stability of the OP-AgNPs. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the synthesized AgNPs, which had an average particle size of 46.31 nm and four Bragg reflections at 38.2°, 44.32°, 64.4°, and 77.1°. The Nanomeasurer software confirmed that 89% of the particles had an average size of 50 nm, and the scanning electron microscope analysis also confirmed spherical shaped, monodispersed, high-density AgNPs formation. Energy dispersive X-ray analysis confirmed that silver was the main element with a highest sharp peak at 3.0 keV. We assessed the antibacterial and antifungal activities of the AgNPs and OP extract on the bacteria strains Escherichia coli, Acetobacter, and Staphylococcus epidermidis, and fungi strains Aspergillus nigar and Aspergillus flavus. The AgNPs displayed more potent antibacterial and antifungal inhibition abilities than the plant. Similarly, in 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azobis,3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and hydrogen peroxide (H₂O₂) assays, AgNPs displayed better reduction capacities than the plant extract.