title: Configuration of microbially synthesized Pd-Au nanoparticles studied by STEM-based techniques.
abstract: Bimetallic Pd-Au particles synthesized using Desulfovibrio desulfuricans bacteria are characterized using scanning transmission electron microscopy (STEM) with a high-angle annular dark field (HAADF) detector combined with energy dispersive x-ray (EDX) silicon drift detector (SDD) elemental mapping and plasmon electron energy-loss spectroscopy (EELS). When combined with EDX, theoretical considerations or EELS, the atomic-number contrast (Z-contrast) provided by HAADF-STEM is effective in characterizing the compositional configuration of the bimetallic nanoparticles. Homogeneous mixing and complex segregations have been found for different particles in this work. The EELS study has also found different behaviours corresponding to surface plasmon resonances in different regions of a single particle due to its heterogeneity and anisotropy. HAADF-STEM tomography has been performed to obtain three-dimensional (3D) visualization of the nanoparticles.
authors.affiliation: School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: D T
authors.initials: DT
authors.lastname: Tran
authors.forename: I P
authors.initials: IP
authors.lastname: Jones
authors.forename: J A
authors.initials: JA
authors.lastname: Preece
authors.forename: R L
authors.initials: RL
authors.lastname: Johnston
authors.forename: K
authors.initials: K
authors.lastname: Deplanche
authors.forename: L E
authors.initials: LE
authors.lastname: Macaskie
mesh_terms: D045285:Desulfovibrio desulfuricans / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017348:Microscopy, Electron, Scanning Transmission / Q000379:methods*; D008958:Models, Molecular; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size
chemical_list: D010165:Palladium; D006046:Gold