Silver-based crystalline nanoparticles, microbially fabricated
- Department of Materials Science, The Ångström Laboratory, Uppsala University, P. O. Box 534, SE-751 21 Uppsala, Sweden.
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Edited by Frank H. Stillinger, Bell Laboratories, Lucent Technologies, Murray Hill, NJ, and approved September 21, 1999 (received for review May 20, 1999)
Abstract
One mechanism of silver resistance in microorganisms is accumulation of the metal ions in the cell. Here, we report on the phenomenon of biosynthesis of silver-based single crystals with well-defined compositions and shapes, such as equilateral triangles and hexagons, in Pseudomonas stutzeri AG259. The crystals were up to 200 nm in size and were often located at the cell poles. Transmission electron microscopy, quantitative energy-dispersive x-ray analysis, and electron diffraction established that the crystals comprise at least three different types, found both in whole cells and thin sections. These Ag-containing crystals are embedded in the organic matrix of the bacteria. Their possible potential as organic-metal composites in thin film and surface coating technology is discussed.
Footnotes
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↵ * To whom reprint requests should be addressed. E-mail: Tanja.Klaus{at}angstrom.uu.se.
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This paper was submitted directly (Track II) to the PNAS office.
- Abbreviations:
- TEM,
- transmission electron microscopy;
- EDX,
- energy-dispersive x-ray analysis
- Copyright © 1999, The National Academy of Sciences
