Purity of graphene oxide determines its antibacterial activity
Purity of graphene oxide determines its antibacterial activity
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DOI：
10.1088/2053-1583/3/2/025025
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发表时间：
2016-06-01
期刊：
影响因子：
5.5
通讯作者：
Roberts, I. S.
中科院分区：
文献类型：
--
作者：
Barbolina, I.;Woods, C. R.;Roberts, I. S.
基于二维（2D）原子晶体的纳米材料被认为是非常有前途的各种生命科学和医学应用，从药物输送到组织修饰。用于这些目的的最合适的材料之一是氧化石墨烯（GO），这要归功于良好的生产方法和水溶性。同时，其生物学效应仍有争议。在这里，我们证明了高度纯化和彻底洗涤的GO既不抑制也不刺激E. coli，ATCC 25922; coliNCIMB 11943和S.金黄色葡萄球菌ATCC 25923，浓度高达1 mg/ml（-1）。此外，GO暴露细菌的透射电子显微镜（TEM）没有显示GO暴露和未暴露人群之间的任何差异。相比之下，未充分纯化的GO的悬浮液由于可溶性酸性杂质的存在而表现为抗菌材料，所述可溶性酸性杂质可以通过延长的纯化或通过碱性底物的中和来去除。一个标准化的协议提出了清洁GO的生成，所以它变得适合生物实验。我们的研究结果强调了在处理生物系统时GO纯化状态的重要性，因为材料的真实效果可能会被杂质的影响所掩盖。
Nanomaterials based on two-dimensional (2D) atomic crystals are considered to be very promising for various life-science and medical applications, from drug delivery to tissue modification. One of the most suitable materials for these purposes is graphene oxide (GO), thanks to a well-developed methods of production and water solubility. At the same time, its biological effect is still debated. Here we demonstrate that highly purified and thoroughly washed GO neither inhibited nor stimulated the growth of E. coli, ATCC25922; E. coli NCIMB11943 and S. aureus ATCC25923 at concentrations of up to 1 mg ml(-1). Moreover, transmission electron microscopy (TEM) of GO exposed bacteria did not reveal any differences betweenGOexposed and not exposed populations. In contrast, a suspension of insufficiently purified GO behaved as an antibacterial material due to the presence of soluble acidic impurities, that could be removed by extended purification or neutralisation by alkaline substrates. A standardised protocol is proposed for the generation of clean GO, so it becomes suitable for biological experiments. Our findings emphasise the importance of GO purification status when dealing with biological systems as the true effect of material can be masked by the impact of impurities.