The green synthesis of silver nanoparticles (AgNPs) has been attractive in biomedical applications due to its nontoxic and eco-friendly approach. This study presents the facile, rapid, and cost-effective synthesis of AgNPs by photoassisted chemical reduction using Riceberry (RB) rice extract as a reducing agent. The effects of reaction parameters including photoirradiation, irradiation time, the volume ratio of silver nitrate (AgNO₃) to RB extract, and pH condition on the AgNP formation were also investigated. The characterization of AgNPs was determined by UV–visible spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. For antibacterial application, the synthesized AgNPs were studied by disc diffusion method against Escherichia coli and Staphylococcus aureus. The results indicated that light irradiation was an important factor to accelerate the formation of AgNPs. The synthesis parameters including volume of RB extract and pH condition significantly affected the particle size and crystallinity of AgNPs. The volume ratio of AgNO₃ to RB extract 1 : 12.5 at pH 2.5 under photoirradiation was the successful condition to form nanometer-sized crystalline particles (average particle size of ) within 30 min with a rate constant of 0.210 min^–1. The FT-IR measurement also suggested that the phytochemical constituents in RB extract were served as reducing and stabilizing agents for the synthesis of AgNPs. Additionally, the obtained AgNPs from various conditions demonstrated the antibacterial activity against both strains. Therefore, this study proposes an effective integration technique to synthesize AgNPs within a short time for antibacterial application.

中文翻译：

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水稻浆果提取物光辅助合成银纳米粒子及其抗菌应用

银纳米粒子（AgNPs）的绿色合成由于其无毒和环保的方法在生物医学应用中一直很有吸引力。本研究展示了使用 Riceberry (RB) 大米提取物作为还原剂通过光辅助化学还原轻松、快速且经济地合成 AgNPs。还研究了反应参数，包括光照射、照射时间、硝酸银 (AgNO ₃ ) 与 RB 提取物的体积比以及 pH 条件对 AgNP 形成的影响。AgNPs 的表征通过紫外-可见光谱、扫描电子显微镜 (SEM)、X 射线衍射 (XRD) 和傅里叶变换红外 (FT-IR) 光谱确定。对于抗菌应用，通过圆盘扩散法研究合成的 AgNPs大肠杆菌和金黄色葡萄球菌。结果表明光照射是加速AgNPs形成的重要因素。合成参数包括 RB 提取物的体积和 pH 条件显着影响 AgNPs 的粒径和结晶度。在 pH 2.5 条件下，AgNO ₃与 RB 提取物的体积比1 : 12.5 是形成纳米级结晶颗粒的成功条件（平均粒径为) 30 分钟内，速率常数为 0.210 分钟^–1。FT-IR 测量还表明 RB 提取物中的植物化学成分可作为合成 AgNPs 的还原剂和稳定剂。此外，从各种条件下获得的 AgNPs 证明了对两种菌株的抗菌活性。因此，本研究提出了一种有效的集成技术，可以在短时间内合成用于抗菌应用的 AgNPs。