title: Superparamagnetic plasmonic nanohybrids: shape-controlled synthesis, TEM-induced structure evolution, and efficient sunlight-driven inactivation of bacteria.
abstract: Magnetic materials and noble metal-based multifunctional hybrids have attracted much attention recently due to their unique properties and potential applications in a variety of fields. However, substantial challenges remain to directly obtain water-soluble hybrids with well-defined structures and to directly combine magnetic nanoparticles with nonspherical noble metals. We describe here for the first time a simple solvothermal method to synthesize a series of novel water-soluble nanohybrids composed of shape-tuned Ag cores and a Fe(3)O(4) shell. We found that small Fe(3)O(4) grains can be well-distributed directly on the surface on the Ag seeds. Such hybrids have both plasmonic and significant superparamagnetic properties, enabling magnetic separation. The plasmon resonance frequency of Ag nanostructures can be fine-tuned through the interactions between the two components. In addition, the decorated Fe(3)O(4) nanoparticles stabilized the Ag nanostructures when exposed to air and natural light for a long time. Furthermore, an interesting structural transformation is observed in the one-dimensional Ag-Fe(3)O(4) nanowires under high-energy electron beam. The Ag core can diffuse through the porous iron oxide shell, break away, and result in the formation of Ag nanocluster-decorated iron oxide tubes. Finally, the hybrids acted as a chemical template for the synthesis of Fe(3)O(4)/Au-AgCl double-layer nanotubes that display obvious near-infrared absorption. Importantly, the double-layer nanotubes exhibited enhanced photocatalytic inactivation of bacteria at very low concentrations under natural sunlight.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Changchun 130022, Jilin, People's Republic of China.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Zhai
authors.forename: Lei
authors.initials: L
authors.lastname: Han
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Gaiping
authors.initials: G
authors.lastname: Li
authors.forename: Wen
authors.initials: W
authors.lastname: Ren
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D002384:Catalysis; D004926:Escherichia coli / Q000187:drug effects* / Q000528:radiation effects; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D050296:Microbial Viability / Q000187:drug effects* / Q000528:radiation effects; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000379:methods*; D053770:Nanowires / Q000737:chemistry; D016062:Porosity; D012834:Silver / Q000737:chemistry*; D012995:Solubility; D013472:Sunlight; D014867:Water / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D058185:Magnetite Nanoparticles; D014867:Water; D012834:Silver