Two different hydrogenase enzymes from sulphate-reducing bacteria are responsible for the bioreductive mechanism of platinum into nanoparticles

Microbial Synthesis of Metal Nanoparticles

“…Fig. 7.5 Postulated mechanism for the double two-electron reduction of Pt +4 into Pt 0 nanoparticles (Riddin et al 2009) It was also reported ) that the extracellular formation of UO 2 nanoparticles by Shewanella putrefaciens strain CN32 involved the outer membrane cytochromes. Finally, Marshall et al (2006) showed that c-type cytochromes of a dissimilatory metal-reducing bacterium S. oneidensis MR-1 are essential for the reduction of U +6 and the extracellular deposition of UO 2 nanoparticles.…”

“…Another example of bioreduction of Pt +4 into the Pt 0 nanoparticles was demonstrated by Riddin et al (2009). A mixed and uncharacterized consortium of sulphate-reducing bacteria was used to investigate the mechanism in the platinum nanoparticle formation.…”

Enzymatic Synthesis of Platinum Nanoparticles: Prokaryote and Eukaryote Systems

“…Both prokaryotic and eukaryotic organisms including bacteria, fungi, actinomycetes and yeasts synthesise biogenic geometric metal particles, in the nanometre range via a bioreductive process, when exposed to metal chloride solutions (Ahmad et al 2003a, b;Sastry et al 2003;Mukherjee et al 2003;Riddin et al 2006Riddin et al , 2009Ingle et al 2008Ingle et al , 2009Govender et al 2009Govender et al , 2010Rai et al 2008Rai et al , 2009aGade et al 2008;Birla et al 2009). This bioreduction of metal particles occurred via an active and/or passive process.…”

A novel biological approach on extracellular synthesis and characterization of semiconductor zinc sulfide nanoparticles

“…The development of semiconductor nanoparticles by using bio-route is an interesting progress in the modern research of nanotechnology. Considerable enthusiasm is now emerging from the current literature about the multidisciplinary field of nanobiotechnology within biological systems (Penn et al 2003;Riddin et al 2006). Recently, the synthesis of chalcogenides of different groups has involved considerable awareness due to their important nonlinear (Brus 1991) luminescent properties, quantum size effects and other important physical and chemical properties (Murray et al 1995;Qiao et al 2000).…”

“…The chemical and physical procedures could be used for the synthesis of semiconductor nanoparticle; however, these methods are fraught with many problems including use of toxic solvents, generation of hazardous by-products and high energy consumption. Accordingly, there is an essential need to develop environmentally benign procedures for synthesis of nanoparticles (Riddin et al 2006). The biological synthesis of nanoparticle has been currently explored through bacteria (Joerger et al 2000), yeast (Kowshik et al 2003), fungi (Mandal et al 2006), plant biomass (Armendariz et al 2004) and live plants (Sharma et al 2007;Longoria et al 2011).…”