Juniperus pseudosabina extract-mediated green synthesis of zinc oxide artichoke-like structures for antibacterial applications

The green synthesis of zinc oxide (ZnO) using plant extracts provides an environmentally friendly alternative to conventional chemical and physical methods. This study investigates the green synthesis of ZnO using Juniperus pseudosabina (J. plseudosabina) extract, eliminating the need for thermal treatment and pH adjustment with alkali metal hydroxides. ZnO nanoparticles are synthesized by varying the plant extract volume (0–20 mL) in a 95 mL aqueous solution of Zn(NO₃)₂·6H₂O. The optimal ratio (5 mL extract) yields phase-pure ZnO with an artichoke-like morphology. The possible formation mechanism of these structures is discussed. Additionally, ZnO is modified with silver (Ag) at concentrations of 0–3 at% to improve antibacterial properties. Structural and morphological characterizations confirm the formation of phase-pure ZnO with high crystallinity. Viable plate count assays demonstrate that both non-modified and Ag-modified ZnO exhibited strong antibacterial activity against Staphylococcus aureus and Escherichia coli, achieving 99.999 % bacterial inactivation. These findings suggest that ZnO and Ag-modified ZnO synthesized using J. pseudosabina extract can be a sustainable antibacterial agent, supporting its application in biomedical and environmental fields.