Abstract: Plant-mediated synthesis of zinc oxide nanoparticles (ZnO-NPs) using leaf extracts is an active research area because phytochemicals serve as eco-friendly reducing and capping agents and because ZnO-NPs show promising antibacterial and antioxidant activities. This manuscript-length summary presents a compact, standardized template that synthesizes common experimental practices used when researchers compare ZnO-NPs produced from five representative leaves (Moringa oleifera, Azadirachta indica (neem), Ocimum spp / Ocimum sanctum (tulsi), Hibiscus cannabinus / Hibiscus spp., and Citrus aurantium / Citrus spp. (orange). It describes comparative study on step-by-step extract preparation and nanoparticle formation (precursors, pH control, reaction conditions, isolation and calcination), recommended characterization workflows (UV–Vis, XRD, FTIR, and FESEM), and standardized biological testing (antibacterial activity against Staphylococcus aureus and E. coli bacteria, while antioxidant activity studied against the DPPH free radical with IC₅₀ reporting). Typical physicochemical signatures of biosynthesized ZnO-NPs are summarized (UV absorption ~ 320–380 nm; XRD wurtzite peaks at 2θ ≈ 31.7°, 34.4°, 36.2°, etc.; FTIR bands indicating phytochemical capping and Zn–O vibrations at 400–600 cm⁻¹). Finally, we present concise conclusions and a recommended reporting checklist to improve reproducibility and enable quantitative cross-study comparison.

Keywords: ZnO Nanoparticles, Moringa oleifera, Azadirachta indica (neem), Ocimum spp. (tulsi), Hibiscus spp., and Citrus aurantium.

Downloads: | DOI: 10.17148/IARJSET.2025.121105