Plant-mediated synthesis of ZnO nanoparticles using Rumex nepalensis extract and physicochemical characterization and biological applications.

Green synthesis has emerged as a sustainable and environmentally friendly strategy for the rapid production of nanoparticles. Zinc oxide (ZnO) nanoparticles were synthesized using Rumex nepalensis (Spreng.) leaf extract, which served as a natural reducing and stabilizing agent. This eco-friendly synthesis approach provides an alternative to conventional chemical methods by avoiding the use of toxic chemicals and minimizing environmental hazards. Structural analysis using X-ray diffraction (XRD) confirmed the formation of ZnO nanoparticles with a hexagonal wurtzite crystalline structure. Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDX) further verified the presence of Zn-O bonds and indicated a high degree of elemental purity. Morphological characterization through scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the nanoparticles were mainly spherical in shape, with particle sizes ranging from approximately 11 to 13 nm. Optical analysis using UV-Visible spectroscopy showed a band gap energy of 3.26 eV, confirming the semiconducting properties of the synthesized nanoparticles. ZnO nanoparticles demonstrated significant antibacterial activity against human pathogenic bacteria, highlighting their potential as effective antimicrobial agents. The strong antioxidant activity was observed, indicating their capability to scavenge free radicals and mitigate oxidative stress, the results confirm the successful green synthesis of ZnO nanoparticles using R. nepalensis extract and emphasize their structural stability, biocompatibility, and diverse biological activities. These findings suggest promising applications of the biogenic ZnO nanoparticles in biomedical, cosmetic, and industrial fields, further supporting the role of green nanotechnology in the development of sustainable nanomaterials.