Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Euphorbia lateriflora Leaf Extract: Evaluation of Antimicrobial and Antioxidant Activities

Abstract

The biosynthesis of zinc oxide nanoparticles (ZnO NPs) using plant extracts has emerged as an environmentally friendly and cost-effective alternative to conventional chemical and physical methods. This study reports the green synthesis of ZnO NPs using aqueous leaf extract of Euphorbia lateriflora as both reducing and stabilizing agent. The biosynthesized nanoparticles were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). UV-Vis spectroscopy revealed characteristic absorption peak at 260 nm, confirming the formation of ZnO NPs. FTIR analysis identified functional groups responsible for reduction and stabilization of nanoparticles. XRD patterns indicated crystalline monoclinic structure with diffraction peaks corresponding to JCPDS-36-1451. SEM analysis showed spherical morphology with polydispersed distribution. Phytochemical screening of Euphorbia lateriflora methanolic extract revealed presence of alkaloids, steroids, cardiac glycosides, saponins, sterols, terpenes, terpenoids, and flavonoids. The biosynthesized ZnO NPs demonstrated significant antibacterial activity against Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa, with inhibition zones of 27.00 ± 2.42 mm, 21.00 ± 1.83 mm, and 17.00 ± 1.25 mm respectively. Antioxidant assays showed DPPH radical scavenging activity with IC₅₀ value of 111.07 ± 15.72 μg/mL and FRAP value of 1.88 ± 0.06 μg/g. These findings demonstrate that Euphorbia lateriflora-mediated ZnO NPs possess promising antimicrobial and antioxidant properties suitable for biomedical applications.