Biofabrication of discrete spherical gold nanoparticles using the metal-reducing bacterium, Shewanella oneidensis

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Acta Biomaterialia

DOI:https://doi.org/10.1016/j.actbio.2011.01.023· OSTI ID:1081676

Suresh, Anil K ^[1]; Pelletier, Dale A ^[1]; Wang, Wei ^[1]; Broich, Michael L ^[1]; Moon, Ji Won ^[1]; Gu, Baohua ^[1]; Allison, David P ^[1]; Joy, David Charles ^[1]; Phelps, Tommy Joe ^[1]; Doktycz, Mitchel John ^[1]

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1. ORNL

Nanocrystallites have garnered substantial interest due to their varying applications including catalysis. Consequently important aspects related to control of shape/size and syntheses through economical and non-hazardous means are desirable. Highly efficient bioreduction based natural fabrication approaches that utilize microbes and or -plant extracts are poised to meet these needs. Here we show that the gamma- proteobacterium, Shewanella oneidensis MR-1, can reduce tetrachloro aurate (III) ions, producing discrete extracellular spherical gold nanocrystallites. The particles were homogeneous with multiple size distributions and produced under ambient conditions at high yield, 88% of theoretical maximum. Further characterization revealed that the particles consist of spheres in the size range of 2-50 nm, with an average of 12 5 nm. The nanoparticles were hydrophilic, biocompatible, and resisted aggregation even after several months. The particles are likely capped by a detachable protein/peptide coat. UV-vis and Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectra and transmission electron microscopy measurements confirmed the formation as well the crystalline nature of the nanoparticles. The antibacterial activity of these gold nanoparticles was assessed using Gram-negative (E. coli and S. oneidensis) and Gram-positive (B. subtilis) bacteria. Toxicity assessments divulged that the particles were neither toxic nor inhibitory to any of these bacteria.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1081676
• Journal Information: Acta Biomaterialia, Vol. 7, Issue 5; ISSN 1742-7061
• Country of Publication: United States
• Language: English