Microbially supported synthesis of catalytically active bimetallic Pd-Au nanoparticles

Authors

  • Baharak Hosseinkhani,

    1. Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, I.R. Iran
    2. Department of Biological Sciences, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark; telephone: +45 60202794; fax: +45 8942 2722
    3. Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
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  • Lina Sveidal Søbjerg,

    1. Department of Biological Sciences, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark; telephone: +45 60202794; fax: +45 8942 2722
    2. Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
    3. Department of Chemistry, Aarhus University, Aarhus C, Denmark
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  • Amelia-Elena Rotaru,

    1. Department of Biological Sciences, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark; telephone: +45 60202794; fax: +45 8942 2722
    2. Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
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  • Giti Emtiazi,

    1. Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, I.R. Iran
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  • Troels Skrydstrup,

    1. Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
    2. Department of Chemistry, Aarhus University, Aarhus C, Denmark
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  • Rikke Louise Meyer

    Corresponding author
    1. Department of Biological Sciences, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark; telephone: +45 60202794; fax: +45 8942 2722
    2. Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
    • Department of Biological Sciences, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark; telephone: +45 60202794; fax: +45 8942 2722.
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Abstract

Bimetallic nanoparticles are considered the next generation of nanocatalysts with increased stability and catalytic activity. Bio-supported synthesis of monometallic nanoparticles has been proposed as an environmentally friendly alternative to the conventional chemical and physical protocols. In this study we synthesize bimetallic bio-supported Pd-Au nanoparticles for the first time using microorganisms as support material. The synthesis involved two steps: (1) Formation of monometallic bio-supported Pd(0) and Au(0) nanoparticles on the surface of Cupriavidus necator cells, and (2) formation of bimetallic bio-supported nanoparticles by reduction of either Au(III) or Pd(II) on to the nanoparticles prepared in step one. Bio-supported monometallic Pd(0) or Au(0) nanoparticles were formed on the surface of C. necator by reduction of Pd(II) or Au(III) with formate. Addition of Au(III) or Pd(II) to the bio-supported particles resulted in increased particle size. UV–Vis spectrophotometry and HR-TEM analyses indicated that the previously monometallic nanoparticles had become fully or partially covered by Au(0) or Pd(0), respectively. Furthermore, Energy Dispersive Spectrometry (EDS) and Fast Fourier Transformation (FFT) analyses confirmed that the nanoparticles indeed were bimetallic. The bimetallic nanoparticles did not have a core-shell structure, but were superior to monometallic particles at reducing p-nitrophenol to p-aminophenol. Hence, formation of microbially supported nanoparticles may be a cheap and environmentally friendly approach for production of bimetallic nanocatalysts. Biotechnol. Bioeng. 2012;109: 45–52. © 2011 Wiley Periodicals, Inc.

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