Synthesis and characterization of zinc oxide nanoparticles by the aerial part of Artemisia roxburghiana extract and assessment of their biological activities.

The zinc oxide nanoparticle (ZnONPs) used in this study were synthesized using Artemisia roxburghiana extract (aerial part). The absorption peak at 353 nm in UV spectroscopy indicates the production of zinc oxide nanoparticles. The synthesis of ZnONPs using extracts of the aerial part of A. roxburghiana is also supported by FTIR peaks around 622 cm-1. DLS analysis showed the synthesis of A-ZnONPs (zinc oxide nanoparticle synthesized by extracts of aerial part A. roxburghiana) with a particle size of 6-10 nm. XRD pattern's detection of a hexagonal crystal structure of A-ZnONPs. HRTEM image confirming the preparation of irregularly shaped A-ZnONPs. The preparation, capping, and stabilization of A-ZnONPs are facilitated by bioactive compounds in the plant's aerial parts. This gives a plant with high total phenol content (TPC) of 93.4 ± 0.53 μg GAE/mg and total flavonoid content (TFC) of 23.22 ± 0.23 μg CE/mg, both of which are responsible for antioxidant activities. A-ZnONPs exhibited more significant antioxidant activity (IC50 = 147.4 μg/mL) and antibacterial activity against Salmonella abony, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. A-ZnONPs exhibited improved inhibition as their concentration increased. A maximum inhibition zone of 23 mm is observed for E. coli, suggesting that it has antibacterial and antioxidant properties to combat illnesses.