A simple and green chemical method has been developed to synthesize stable bare and capped silver nanoparticles based on the reduction of silver ions by glucose and capping by poly(α,γ,l-glutamic acid) (PGA). The use of ammonia during synthesis was avoided. PGA has had a dual role in the synthesis and was used as a capping agent to make the silver nanoparticle more biocompatible and to protect the nanoparticles from agglomerating in the liquid medium. The synthesized PGA-capped silver nanoparticles in the size range 5–45 nm were stable over long periods of time, without signs of precipitation. Morphological examination has shown that the silver nanoparticles had a nearly spherical, multiply twinned structure. The effects of the reaction temperature and the reaction time during the synthesis were investigated too. The biocompatibility of the PGA-capped silver nanoparticles is discussed in terms of in vitro toxicity with human intestinal Caco-2 cells. The samples were characterized by UV–Visible spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and zeta potential measurements.

中文翻译：

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一种新的、简单的、绿色的、一锅四组分合成裸露和聚（α,γ,l-谷氨酸）封端的银纳米粒子

基于葡萄糖还原银离子和聚（α，γ，l-谷氨酸）（PGA）封端，开发了一种简单且绿色的化学方法来合成稳定的裸露和封端的银纳米粒子。避免在合成过程中使用氨。PGA 在合成中具有双重作用，并被用作封端剂，使银纳米颗粒更具生物相容性并保护纳米颗粒在液体介质中不结块。尺寸范围为 5-45 nm 的合成的 PGA 封端的银纳米粒子在很长一段时间内是稳定的，没有沉淀的迹象。形态学检查表明，银纳米粒子具有近乎球形的多重孪晶结构。还研究了合成过程中反应温度和反应时间的影响。根据对人肠道 Caco-2 细胞的体外毒性讨论了 PGA 封端的银纳米粒子的生物相容性。通过紫外-可见光谱、场发射扫描电子显微镜、透射电子显微镜和 zeta 电位测量对样品进行表征。