Abstract Biogenic synthesis of silver nanoparticle (AgNPs) has attracted worldwide attention as it is cheap and non-toxic. Therefore, in present study sunlight mediated silver nanoparticle was synthesized from Azadirachta indica A. Juss (Neem) leaf extract. Various combinations i.e., reducing agent (5, 10, 15 and 20 ml leaf extract), substrate concentration (1 mM AgNO3) and sunlight durations (5, 10, 15 and 20 min) were assessed for their ability to synthesized stabilized AgNPs. Leaf extract provide both reducing and capping agent, while sunlight served as catalyst for the synthesis process. The green synthesized AgNPs were characterized using change in color due to Surface Plasmon Resonance further analyzed by UV–visible spectroscopy, dynamic light scattering for size, polydispersity index and zeta potential for stability studies and Fourier Transform Infrared Spectroscopy (FT-IR). The smallest size of synthesized AgNPs was 67.94 ± 0.72 nm synthesized using to 20 ml of reducing agent (leaf extract) and 5 min of sunlight exposure. Antibacterial activity of synthesized silver nanoparticle was examined against plant pathogen Xanthomonas oryzae pv. oryzae (Xoo) and showed a good antimicrobial activity compared to 200 mg/l of streptocycline.

中文翻译：

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日光介导的印楝叶提取物绿色合成银纳米颗粒的比较研究及其对米黄单胞菌的抗菌作用

摘要 银纳米颗粒（AgNPs）的生物合成因其廉价、无毒而受到全世界的关注。因此，在目前的研究中，阳光介导的银纳米颗粒是由印楝 (Azadirachta indica A. Juss) (Neem) 叶提取物合成的。评估了各种组合，即还原剂（5、10、15 和 20 毫升叶提取物）、底物浓度（1 mM AgNO3）和阳光持续时间（5、10、15 和 20 分钟）合成稳定的 AgNPs 的能力。叶提取物提供还原剂和封端剂，而阳光则作为合成过程的催化剂。绿色合成的 AgNPs 使用由于表面等离子体共振引起的颜色变化进行表征，通过紫外-可见光谱、动态光散射尺寸、用于稳定性研究和傅立叶变换红外光谱 (FT-IR) 的多分散指数和 zeta 电位。合成的 AgNPs 的最小尺寸为 67.94 ± 0.72 nm，使用 20 ml 还原剂（叶提取物）和 5 分钟的阳光照射合成。检查合成的银纳米颗粒对植物病原体米黄单胞菌 pv. 的抗菌活性。oryzae (Xoo)，与 200 mg/l 的链环素相比，显示出良好的抗菌活性。