title: Intrinsic catalytic activity of Au nanoparticles with respect to hydrogen peroxide decomposition and superoxide scavenging.
abstract: Gold nanoparticles have received a great deal of interest due to their unique optical and catalytic properties and biomedical applications. Developing applications as well as assessing associated risks requires an understanding of the interactions between Au nanoparticles (NPs) and biologically active substances. In this paper, electron spin resonance spectroscopy (ESR) was used to investigate the catalytic activity of Au NPs in biologically relevant reactions. We report here that Au NPs can catalyze the rapid decomposition of hydrogen peroxide. Decomposition of hydrogen peroxide is accompanied by the formation of hydroxyl radicals at lower pH and oxygen at higher pH. In addition, we found that, mimicking SOD, Au NPs efficiently catalyze the decomposition of superoxide. These results demonstrate that Au NPs can act as SOD and catalase mimetics. Since reactive oxygen species are biologically relevant products being continuously generated in cells, these results obtained under conditions resembling different biological microenvironments may provide insights for evaluating risks associated with Au NPs.
authors.affiliation: Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD 20740, USA.
authors.forename: Weiwei
authors.initials: W
authors.lastname: He
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Zhou
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Wamer
authors.forename: Xiaona
authors.initials: X
authors.lastname: Hu
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zheng
authors.forename: Mary D
authors.initials: MD
authors.lastname: Boudreau
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Yin
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002384:Catalysis; D006046:Gold / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D017665:Hydroxyl Radical / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*
chemical_list: D013481:Superoxides; D017665:Hydroxyl Radical; D006046:Gold; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase