Physical and antibacterial properties of ZnO particles prepared via green synthesis from Xanthium strumarium extracts

Background: Green synthesized zinc oxide nanoparticles (ZnO NPs) exhibit pharmaceutical properties, including antibacterial activity.However, a significant concern is their potential cytotoxicity due to the penetration and accumulation of small nanoparticles in the body.This study aimed to develop a green synthesis method for ZnO particles with sizes exceeding 100 nm, thereby mitigating cytotoxic concerns while preserving their physical and antibacterial properties.Objectives: To synthesize ZnO particles from X. strumarium leaf extract using a green synthesis and to investigate their physical properties and antibacterial activity. Methods:The physical characteristics of the synthesized ZnO particles were investigated using analytical techniques, including X-ray diffraction, UV-vis spectrometry, scanning electron microscopy, and Fourier transform infrared analysis.The in vitro antibacterial activity of these particles was assessed through the agar disk diffusion method and the determination of half maximum inhibitory concentration (IC 50 ). Results:The ZnO particles synthesized via green synthesis using X. strumarium exhibited a crystalline hexagonal wurtzite structure, with an average particle size of 574 137 nm.The resulting ZnO particles, denoted as 2MZnO-4Xs, displayed a flower-like shape and showed a UV-spectrum peak around 376 nm.These particles retained phytochemicals from the extract on their surface.Importantly, they exhibited antibacterial activity against Bacillus subtilis and Staphylococcus aureus, with IC 50 values of 5.81 mg/mL and 2.26 mg/mL, respectively. Conclusion:The green synthesis of ZnO particles larger than 100 nm using X. strumarium was successfully achieved.The obtained ZnO particles exhibited antibacterial activity against pathogenic Gram-positive bacteria, demonstrating their potential as effective antimicrobial agents.