This study synthesized silver nanoparticles (AgNPs) using Vernonia amygdalina leaf extract, employing a sustainable and eco-friendly green synthesis approach. Characterization of the green-synthesized AgNPs was conducted using various analytical techniques, including UV-visible, FTIR, DLS, SEM, TEM, XRD, EDX, and assessment of their antioxidant and antimicrobial properties. The presence of AgNPs was indicated by the maximum absorbance at 430 nm. In the case of Va-AgNPs nanocomposites, two distinct peaks were observed at 417 nm and 230 nm, providing confirmation of the formation of AgNPs with caps. These bands suggest the adsorption of flavonoids and triterpene acids in the capping layer of the nanoparticles. Additionally, the peak at 1618.02 cm^–1 and the intense band at 1060.01 cm^–1 correspond to N-H bonds and ether groups (C–O bond stretch), respectively. DLS analysed Z-Average Size is measured at 70.00 ± 10.0 nm with a PDI of 0.600 ± 0.02, and a Zeta potential of -22.00 ± 1.5 mV. SEM analysis confirmed nanoparticle sizes ranging from 10 to 25 nm, contributing to the morphological and characterization analysis of AgNPs. TEM analysis revealed V. amygdalina-synthesized AgNPs as spherical, 20–50 nm in diameter. Biosynthesized AgNPs with small crystallite size and cubic spinel ferrite structure effectively degrade dyes and pathogens, closely matching standard cubic-phase AgNPs (JCPDS card number 22-1089) in 2-theta values and (hkl) plane values (220), (311), (222), (400), (422), (511), and (400). EDX analysis shows 54% oxygen and 40% AgNPs in the synthesized material, with excess oxygen likely coming from the glass substrate. In-vitro antioxidant activity of V. amygdalina extract AgNPs effectively reduced DPPH, ABTS, and superoxide radicals in a dose-dependent manner. V. amygdalina AgNPs showed the highest antibacterial activity against Gram-negative pathogens, including E. coli, S. typhi, V. cholerae, and P. vulgaris. These findings underscore the potential of Vernonia amygdalina-synthesized AgNPs, rich in polyphenolic compounds, for pharmacological applications of antipyretic and anticancer properties.

本研究利用斑鸠菊叶提取物合成银纳米颗粒（AgNP），采用可持续且环保的绿色合成方法。使用各种分析技术对绿色合成的 AgNP 进行表征，包括紫外-可见光、FTIR、DLS、SEM、TEM、XRD、EDX，并评估其抗氧化和抗菌特性。 430 nm 处的最大吸光度表明 AgNP 的存在。对于Va -AgNPs 纳米复合材料，在 417 nm 和 230 nm 处观察到两个不同的峰，证实了带帽的 AgNPs 的形成。这些条带表明类黄酮和三萜酸吸附在纳米粒子的覆盖层中。此外，1618.02 cm ^–1处的峰和 1060.01 cm ^–1处的强带分别对应于 NH 键和醚基（C-O 键拉伸）。 DLS 分析的 Z 平均尺寸在 70.00 ± 10.0 nm 处测量，PDI 为 0.600 ± 0.02，Zeta 电位为 -22.00 ± 1.5 mV。 SEM 分析证实纳米颗粒尺寸范围为 10 至 25 nm，有助于 AgNP 的形态和表征分析。 TEM 分析显示，V. amygdalina合成的 AgNP 为球形，直径 20-50 nm。生物合成的 AgNP 具有小晶粒尺寸和立方尖晶石铁氧体结构，可有效降解染料和病原体，在 2-theta 值和 (hkl) 平面值方面与标准立方相 AgNP（JCPDS 卡号 22-1089）密切匹配 (220)、(311) 、(222)、(400)、(422)、(511)和(400)。 EDX 分析显示，合成材料中含有 54% 的氧气和 40% 的 AgNP，其中过量的氧气可能来自玻璃基板。苦杏仁提取物 AgNP 的体外抗氧化活性可有效降低 DPPH、ABTS 和超氧自由基，且呈剂量依赖性。V. amygdalina AgNPs 对革兰氏阴性病原体（包括大肠杆菌、伤寒沙门氏菌、霍乱弧菌和寻常假单胞菌）表现出最高的抗菌活性。这些发现强调了杏仁斑鸠菊合成的银纳米颗粒（富含多酚化合物）在解热和抗癌特性的药理学应用中的潜力。