Antibacterial Activity of Graphite, Graphite Oxide, Graphene Oxide, and Reduced Graphene Oxide: Membrane and Oxidative Stress
Antibacterial Activity of Graphite, Graphite Oxide, Graphene Oxide, and Reduced Graphene Oxide: Membrane and Oxidative Stress
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DOI：
10.1021/nn202451x
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发表时间：
2011-09-01
期刊：
影响因子：
17.1
通讯作者：
Chen, Yuan
中科院分区：
文献类型：
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作者：
Liu, Shaobin;Zeng, Tingying Helen;Chen, Yuan
石墨烯基材料的健康和环境影响需要在其潜在应用之前进行彻底评估。石墨烯对细菌具有很强的细胞毒性。为了更好地理解其抗菌机制，我们比较了四种类型的石墨烯基材料（石墨（Gt）、氧化石墨（GtO）、氧化石墨烯（GO）和还原氧化石墨烯（rGO））对细菌模型大肠杆菌的抗菌活性。在相似的浓度和孵育条件下，GO分散体显示出最高的抗菌活性，依次为rGO、Gt和GtO。扫描电子显微镜（SEM）和动态光散射分析表明，GO聚集体具有最小的平均尺寸中的四种类型的材料。SEM图像显示与石墨烯纳米片的直接接触破坏了细胞膜。未检测到超氧阴离子（O-2（中心点-））诱导的活性氧（ROS）产生。然而，这四种类型的材料可以氧化谷胱甘肽，谷胱甘肽在细菌中充当氧化还原状态介体。导电rGO和Gt具有比绝缘GO和GtO更高的氧化能力。结果表明，抗菌作用是由膜和氧化应激。我们建议，一个三步的抗菌机制，以前用于碳纳米管，适用于石墨烯基材料。它包括在石墨烯基材料上的初始细胞沉积，通过与尖锐纳米片直接接触而引起的膜应力，以及随后的超氧阴离子非依赖性氧化。我们设想石墨烯基材料的物理化学性质，如官能团密度，尺寸和导电性，可以精确定制，以降低其健康和环境风险或增加其应用潜力。
Health and environmental Impacts of graphene-based materials need to be thoroughly evaluated before their potential applications. Graphene has strong cytotoxicity toward bacteria. To better understand its antimicrobial mechanism, we compared the antibacterial activity of four types of graphene-based materials (graphite (Gt), graphite oxide (GtO), graphene oxide (GO), and reduced graphene oxide (rGO)) toward a bacterial model Escherichia coli. Under similar concentration and incubation conditions, GO dispersion shows the highest antibacterial activity, sequentially followed by rGO, Gt, and GtO. Scanning electron microscope (SEM) and dynamic light scattering analyses show that GO aggregates have the smallest average size among the four types of materials. SEM images display that the direct contacts with graphene nanosheets disrupt cell membrane. No superoxide anion (O-2(center dot-)) induced reactive oxygen species (ROS) production is detected. However, the four types of materials can oxidize glutathione, which serves as redox state mediator in bacteria. Conductive rGO and Gt have higher oxidation capacities than insulating GO and GtO. Results suggest that antimicrobial actions are contributed by both membrane and oxidation stress. We propose that a three-step antimicrobial mechanism, previously used for carbon nanotubes, is applicable to graphene-based materials. It includes initial cell deposition on graphene-based materials, membrane stress cared by direct contact with sharp nanosheets, and the ensuing superoxide anion-independent oxidation. We envision that physicochemical properties of graphene-based materials, such as density of functional groups, size, and conductivity, can be precisely tailored to either reducing their health and environmental risks or increasing their application potentials.