Makarov Valentin V, Makarova Svetlana S, Love Andrew J, Sinitsyna Olga V, Dudnik Anna O, Yaminsky Igor V, Taliansky Michael E, Kalinina Natalia O
Belozersky Institute of Physico-Chemical Biology and ‡Biological Faculty, ∥Chemical Faculty, and ⊥Physical Faculty, Lomonosov Moscow State University , 119992 Moscow, Russia.
Langmuir. 2014 May 27;30(20):5982-8. doi: 10.1021/la5011924. Epub 2014 May 13.
We report the synthesis and characterization of amorphous iron oxide nanoparticles from iron salts in aqueous extracts of monocotyledonous (Hordeum vulgare) and dicotyledonous (Rumex acetosa) plants. The nanoparticles were characterized by TEM, absorbance spectroscopy, SAED, EELS, XPS, and DLS methods and were shown to contain mainly iron oxide and iron oxohydroxide. H. vulgare extracts produced amorphous iron oxide nanoparticles with diameters of up to 30 nm. These iron nanoparticles are intrinsically unstable and prone to aggregation; however, we rendered them stable in the long term by addition of 40 mM citrate buffer pH 3.0. In contrast, amorphous iron oxide nanoparticles (diameters of 10-40 nm) produced using R. acetosa extracts are highly stable. The total protein content and antioxidant capacity are similar for both extracts, but pH values differ (H. vulgare pH 5.8 vs R. acetosa pH 3.7). We suggest that the presence of organic acids (such oxalic or citric acids) plays an important role in the stabilization of iron nanoparticles, and that plants containing such constituents may be more efficacious for the green synthesis of iron nanoparticles.
我们报道了从单子叶植物（大麦）和双子叶植物（酸模）的水提取物中的铁盐合成及表征非晶态氧化铁纳米颗粒的过程。通过透射电子显微镜（TEM）、吸收光谱、选区电子衍射（SAED）、电子能量损失谱（EELS）、X射线光电子能谱（XPS）和动态光散射（DLS）方法对纳米颗粒进行了表征，结果表明其主要包含氧化铁和羟基氧化铁。大麦提取物产生了直径达30 nm的非晶态氧化铁纳米颗粒。这些铁纳米颗粒本质上不稳定且易于聚集；然而，我们通过添加40 mM pH 3.0的柠檬酸盐缓冲液使其长期保持稳定。相比之下，使用酸模提取物制备的非晶态氧化铁纳米颗粒（直径为10 - 40 nm）高度稳定。两种提取物的总蛋白含量和抗氧化能力相似，但pH值不同（大麦pH 5.8，酸模pH 3.7）。我们认为有机酸（如草酸或柠檬酸）的存在对铁纳米颗粒的稳定起着重要作用，并且含有此类成分的植物可能对铁纳米颗粒的绿色合成更有效。
