title: Phase transfer identification of core-shell structures in Ag-Au bimetallic nanoparticles.
abstract: The difference between the transfer of poly(vinylpyrrolidone)-protected Au and Ag nanoparticles from an aqueous solution to toluene was used to develop a simple experimental procedure that can positively identify the formation of bimetallic Ag-Au nanoparticles with the core-shell structure. The method was validated by UV-visible spectroscopy, EDX, and TEM measurements. Using this technique, we have found that core-shell nanoparticles of Ag-Au were formed by the seed-mediated growth method using Ag nanoparticles as the seeds. The reversed order of using Au nanoparticles as the seeds, on the contrary, could only produce a physical mixture of Ag-Au core-shell nanoparticles and isolated Ag nanoparticles.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: Jim Yang
authors.initials: JY
authors.lastname: Lee
authors.forename: L X
authors.initials: LX
authors.lastname: Chen
authors.forename: Heng-Phon
authors.initials: HP
authors.lastname: Too
mesh_terms: D006046:Gold / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000648:ultrastructure*; D010825:Physics / Q000379:methods; D011205:Povidone / Q000032:analysis; D012834:Silver / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D012834:Silver; D006046:Gold; D011205:Povidone