Microbial synthesis and the characterization of metal-substituted magnetites

Microbial production of gold nanoparticles

“…Examples include the formation of magnetic nanoparticles by magnetotactic bacteria (15), the production of silver nanoparticles by Pseudomonas stutzeri (16), synthesis of nano-scale, semi-conducting CdS crystals in the yeast Schizosaccharomyces pombe (17), and the formation of palladium nanoparticles using sulphate reducing bacteria in the presence of an exogenous electron donor (18). The ability of bacteria, fungi, actinomycetes (19), yeast (20), algae (21) and plants (22) to accumulate gold ions from solution has been reported and the synthesis of gold nanoparticles has been successfully demonstrated in a range of organisms including Bacillus sp.…”

Effects of Microbial Growth Conditions on Synthesis of Magnetite Nanoparticles using Indigenous Fe(III)-Reducing Bacteria

“…Akaganeite (β-FeOOH) was prepared using the following procedure [18]: 10 M NaOH solution was slowly added into 0.4 M FeCl 3 ·6H 2 O solution to precipitate akaganeite (β-FeOOH) by gravity only with rapid stirring at pH 7. The suspension was then aerated overnight by magnetic stirring for homogeneous oxidation.…”

A Magnetocaloric Pump for Lab-On-Chip Technology: Phase I Report

“…As with the milling and chemical precipitation processes, it is possible to incorporate other metals (Mn(II), Co(II), Ni(II), and Cr(III)) into magnetite (Fe 3 O 4 ) structure to control magnetic, electrical, and physical properties of the substituted magnetite. 9 While the understanding of the actual process is still under investigation, magnetic nanoparticles are formed and shed on the skin of the bacteria as they move through iron oxyhydroxides plus soluble metal species, as illustrated in Fig. 4B.…”

“…The akaganeite was prepared as follows: NaOH solution (10 M) was slowly added into a FeCl 2 •6H 2 O solution (0.4 M) to precipitate Fe(OH) 2 by gravity only and with rapid stirring at pH 7.0. 10 The suspension was aerated overnight by magnetic stirring, ensuring homogeneous oxidation. Xray diffraction analysis showed that the magnetite precursor was mainly poorly crystalline akaganeite (ß-FeOOH) ( Fig.…”