title: Antibacterial activity of graphene supported FeAg bimetallic nanocomposites.
abstract: We report the simple one pot synthesis of iron-silver (FeAg) bimetallic nanoparticles with different compositions on graphene support. The nanoparticles are well dispersed on the graphene sheet as revealed by the TEM, XRD, and Raman spectra. The antibacterial activity of graphene-FeAg nanocomposite (NC) towards Bacillus subtilis, Escherichia coli, and Staphylococcus aureus was investigated by colony counting method. Graphene-FeAg NC demonstrates excellent antibacterial activity as compared to FeAg bimetallic without graphene. To understand the antibacterial mechanism of the NC, oxidative stress caused by reactive oxygen species (ROS) and the glutathione (GSH) oxidation were investigated in the system. It has been observed that ROS production and GSH oxidation are concentration dependent while the increase in silver content up to 50% generally enhances the ROS production while ROS decreases on further increase in silver content. Graphene loaded FeAg NC demonstrates higher GSH oxidation capacity than bare FeAg bimetallic nanocomposite. The mechanism study suggests that the antibacterial activity is probably due to membrane and oxidative stress produced by the nanocomposites. The possible antibacterial pathway mainly includes the non-ROS oxidative stress (GSH oxidation) while ROS play minor role.
authors.affiliation: State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Ayyaz
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: State key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Abdul Sattar
authors.initials: AS
authors.lastname: Qureshi
authors.affiliation: State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: State key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Bao
authors.affiliation: Department of Chemical Engineering, Shihezi University, Xinjiang 832000, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. Electronic address: yshxu@ecust.edu.cn.
authors.forename: Yisheng
authors.initials: Y
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; Department of Chemical Engineering, Shihezi University, Xinjiang 832000, China. Electronic address: guoxuhong@ecust.edu.cn.
authors.forename: Xuhong
authors.initials: X
authors.lastname: Guo
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D005978:Glutathione / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D053761:Nanocomposites / Q000737:chemistry*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D017382:Reactive Oxygen Species; D012834:Silver; D006108:Graphite; D007501:Iron; D005978:Glutathione
keywords: Antibacterial activity; FeAg bimetallic; GSH oxidation; Graphene; Reactive oxygen species