Green synthesis of zinc oxide nanoparticles using Urtica dioica leaf extract: Characterization and in vitro analysis of antibacterial activity against phytopathogens

The Urtica dioica plant is a member of the Urticaceae family and has antiproliferative, antioxidant, anti-inflammatory, antiulcer, and anti-infectious qualities that are used in herbal medicines. The objective of this research is to examine the Urtica dioica leaf extract qualitatively, and green synthesis of zinc oxide nanoparticles (ZnO NPs) were characterized using UV-visible spectroscopy, scanning electron microscopy-EDS, and X-ray diffraction. The in vitro antibacterial activity was assessed using agar-well diffusion method, the green ZnO NPs and crude methanolic extract was assessed against Erwinia herbicola and Ralstonia solanacearum. The UV- Vis spectroscopy of green synthesized ZnO NPs showed an absorption peak at 364 nm and XRD analysis exhibited a hexagonal crystalline structure and a crystallite size of 28.17 nm. Flower-shaped surface morphology with aggregation of NPs were observed in SEM analysis. In vitro antibacterial activity of green synthesized ZnO NPs (100 mg/mL) exhibited almost the same zone of inhibition (20±0.66 mm) against Erwinia herbicola and Ralstonia solanacearum (20±0 mm). There was inhibition for crude methanolic extract (100 mg/mL) was 14±0.33 mm against E. herbicola and 15±0.33 mm against R. solanacearum. The green synthesized ZnO NPs can be used as nano-based agricultural products that will increase yield and quality while controlling disease.