Development of biologically inspired experimental procedures for synthesis of nanoparticles (NPs) is an important branch of nanotechnology. Synthesis of NPs which are nontoxic, eco-friendly, inexpensive and having potential medicinal properties is challenging. In present study, gold NPs were produced from Eucalyptus tereticornis leaf extract (Et-AuNPs). The Et-AuNPs were confirmed using UV–Vis absorption study which shows surface plasmon resonance peak at 569 nm. Various characteristics of Et-AuNPs were demonstrated by characterisation techniques such as scanning electron microscopy, transmission electron microscopy, x-ray diffraction and energy dispersive spectroscopy. It is found that prepared Et-AuNPs are well dispersed and spherical in shape. Significant anticancer effect on MCF-7 cell lines was observed in dose-dependent manner having IC₅₀ value of 52.0 μg ml⁻¹. Further antibacterial studies were carried out by disc-diffusion method, which revealed potential antibacterial activity of Et-AuNPs against pathogenic bacterial strains. Et-AuNPs also exhibited promising free radical scavenging efficiency performed by DPPH assay with IC₅₀ values of 62.6 μg ml⁻¹. The results suggest that green synthesised AuNPs can be exploited for clinical as well as pharmaceutical activities using nanomedicine approach in near future.

生物学启发的合成纳米粒子（NP）的实验程序的开发是纳米技术的重要分支。无毒，环保，廉价且具有潜在医学特性的NP的合成具有挑战性。在本研究中，金纳米颗粒是从桉树中产生的叶提取物（Et-AuNPs）。Et-AuNPs通过UV-Vis吸收研究得到证实，该研究显示了在569 nm处的表面等离子体共振峰。Et-AuNPs的各种特性已通过表征技术得到证明，例如扫描电子显微镜，透射电子显微镜，x射线衍射和能量色散光谱。发现制备的Et-AuNPs分散良好并且呈球形。在具有IC剂量依赖性方式观察到对MCF-7细胞系显著抗癌作用₅₀ 52.0的值μ克毫升^-1。通过圆盘扩散法进行了进一步的抗菌研究，揭示了Et-AuNPs对病原细菌菌株的潜在抗菌活性。ET-的AuNP也表现出有前途的通过DPPH试验用IC进行自由基清除效率₅₀的62.6的值μ克毫升^-1。结果表明，在不久的将来，可以使用纳米药物方法将绿色合成的AuNPs用于临床和药物活性。