title: Tailor-made Au@Ag core-shell nanoparticle 2D arrays on protein-coated graphene oxide with assembly enhanced antibacterial activity.
abstract: Water-dispersible two-dimensional (2D) assemblies of Au@Ag core-shell nanoparticles are obtained through a highly selective electroless silver deposition on pre-assembled gold nanoparticles on bovine serum albumin (BSA)-coated graphene oxide (BSA-GO). While neither BSA-GO nor AuNP-decorated BSA-GO shows any antibacterial ability, the silver-coated GO@Au nanosheets (namely GO@Au@Ag) exhibit an enhanced antibacterial activity against Gram-negative Escherichia coli (E. coli) bacteria, superior to unassembled Au@Ag nanoparticles and even ionic Ag. Such an improvement may be attributed to the increased local concentration of silver nanoparticles around a bacterium and a polyvalent interaction with the bacterial surface. In addition, the colloidal stability of this novel nano-antimicrobial against the formation of random nanoparticle aggregates guarantees a minimized activity loss of the Au@Ag nanoparticles. The antibacterial efficacy of GO@Au@Ag is less sensitive to the existence of Cl⁻, in comparison with silver ions, providing another advantage for wound dressing applications. Our research unambiguously reveals a strong and very specific interaction between the GO@Au@Ag nanoassembly and E. coli, which could be an important clue toward a rational design, synthesis and assembly of innovative and highly active antibacterial nanomaterials.
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
authors.forename: Huiqiao
authors.initials: H
authors.lastname: Wang
authors.forename: Jinbin
authors.initials: J
authors.lastname: Liu
authors.forename: Xuan
authors.initials: X
authors.lastname: Wu
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Tong
authors.forename: Zhaoxiang
authors.initials: Z
authors.lastname: Deng
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects; D003102:Colloids; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects; D006046:Gold / Q000737:chemistry* / Q000494:pharmacology; D006108:Graphite / Q000737:chemistry* / Q000494:pharmacology; D053768:Metal Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003102:Colloids; D010087:Oxides; D012710:Serum Albumin, Bovine; D012834:Silver; D006046:Gold; D006108:Graphite