Title of article :
Spectroscopic characterization of gold nanoparticles formed by cells and S-layer protein of Bacillus sphaericus JG-A12
Author/Authors :
Merroun، نويسنده , , M. and Rossberg، نويسنده , , Catherine A. and Hennig، نويسنده , , C. and Scheinost، نويسنده , , A.C. and Selenska-Pobell، نويسنده , , S.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Pages :
5
From page :
188
To page :
192
Abstract :
The strain Bacillus sphaericus JG-A12, isolated from a uranium mining waste pile near the town of Johanngeorgenstadt, is capable of selective and reversible accumulation of U, Cu, Pb, Al, and Cd from uranium waste waters. The cells of this strain are enveloped by a surface layer protein (S-layer). The highly regular structure of this S-layer with many pores of identical size offers good binding sites for different kinds of molecules and provides nucleation sites for the formation of metal nanoclusters or minerals. In this study we demonstrate that B. sphaericus JG-A12 cells and their purified S-layer protein were capable to reduce Au to metallic nanoclusters in the presence of reducing agents such as molecular H2. The gold nanoparticles were regularly distributed and sized according to the pores of the protein lattice. The metallic nature of the clusters was confirmed by different techniques such as extended X-ray absorption fine structure (EXAFS) spectroscopy, X-ray absorption near edge (XANES) spectroscopy, UV–vis spectroscopy and X-ray powder diffraction (XRD). The size of the gold nanoparticles was estimated to be almost 1 nm. Our results demonstrate that B. sphaericus JG-A12 can be used to prepare gold nanoparticles tailor-made for industrial applications.
Keywords :
XRD , Bacillus sphaericus cells , XANES/EXAFS , UV-vis spectroscopy , S-layer protein , Gold nanoparticles
Journal title :
Materials Science and Engineering C
Serial Year :
2007
Journal title :
Materials Science and Engineering C
Record number :
2096416
Link To Document :
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