title: Manufacturing and characterization of Pd nanoparticles formed on immobilized bacterial cells.
abstract: OBJECTIVE
  To fabricate and analyse Pd nanoparticles on immobilized bacterial cells.
  
  
  RESULTS
  Biological ceramic composites (biocers) were used as a template to produce Pd(0) nanoparticles. The metal-binding cells of the uranium mining waste pile isolate, Bacillus sphaericus JG-A12 were used as a biological component of the biocers and immobilized by using sol-gel technology. Vegetative cells and surface-layer proteins of this strain are known to bind high amounts of Pd(II) that can be reduced to Pd(0) particles by the addition of a reducing agent. Sorption of Pd(II) by the biocers from a metal complex solution was studied by inductively coupled plasma mass spectroscopy analyses. After embedding into sol-gel ceramics, the cells retained their Pd(II)-binding capability. Pd(0) nanoclusters were produced by the addition of hydrogen as reducing agent after the sorption of Pd(II). The interactions of Pd(0) with the biocers and the formed Pd(0) nanoparticles were investigated by extended X-ray absorption fine structure spectroscopy. The particles had a size of 0.6-0.8 nm.
  
  
  CONCLUSIONS
  Bacterial cells that were immobilized by embedding into sol-gel ceramics were used as a template to produce Pd nanoclusters of a size smaller than 1 nm. These particles possess interesting physical and chemical properties.
  
  
  CONCLUSIONS
  The use of embedded bacterial cells as template enabled the fabrication of immobilized Pd(0) nanoparticles. These particles are highly interesting for technical applications, such as the development of novel catalysts.
authors.affiliation: Institute of Radiochemistry, Forschungszentrum Rossendorf, Dresden, Germany. k.pollmann@fz-rossendorf.de
authors.forename: K
authors.initials: K
authors.lastname: Pollmann
authors.forename: M
authors.initials: M
authors.lastname: Merroun
authors.forename: J
authors.initials: J
authors.lastname: Raff
authors.forename: C
authors.initials: C
authors.lastname: Hennig
authors.forename: S
authors.initials: S
authors.lastname: Selenska-Pobell
mesh_terms: D001407:Bacillus / Q000302:isolation & purification / Q000378:metabolism*; D018914:Cells, Immobilized; D005782:Gels; D008906:Mining; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010165:Palladium / Q000737:chemistry / Q000378:metabolism*; D010316:Particle Size; D011850:Radioactive Waste; D012988:Soil Microbiology; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D005782:Gels; D011850:Radioactive Waste; D010165:Palladium