Biosynthesis of zinc oxide nanoparticles using <i>Tamarix chinensis</i> extract: evaluation of antioxidant, antimicrobial, and anti-MCF-7 cancer activities

This study explores the green synthesis of zinc oxide nanoparticles (ZnONPs) using <i>Tamarix chinensis</i> extract, known for its hepatoprotective and anti-inflammatory phytochemicals. The ZnONPs were synthesized using ZnSO₄ and NaOH, resulting in an average size of 125 nm, as confirmed by scanning electron microscopy (SEM). X-ray diffraction (XRD) analysis revealed a hexagonal crystalline structure. UV-Vis spectroscopy showed an absorption peak at 360 nm, corresponding to a bandgap of 3.37 eV, making these nanoparticles suitable for controlled drug delivery systems. The antioxidant activity of <i>T. chinensis</i> extract was evaluated using the DPPH assay, demonstrating an 80% inhibition of free radicals at 500 µg/mL, surpassing the antioxidant potential of the ZnONPs. The antimicrobial efficacy of the ZnONPs was evidenced by a minimum inhibitory concentration (MIC) of <50 µg/mL against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>. Additionally, the ZnONPs exhibited antiproliferative activity with an IC₅₀ of 20.80 µg/mL in MCF-7 breast cancer cells, highlighting their potential for biomedical applications. These findings suggest the promising multifunctional role of biosynthesized ZnONPs in healthcare and technological innovations.