Using Cytochrome c₃ To Make Selenium Nanowires

Abstract

The photoelectric and semiconductor properties of selenium are well-known. Selenium is used, e.g., in rectifiers, solar cells, photographic exposure meters, and xerography. 1 There is increasing interest in electronic, magnetic, mechanical, and chemical properties of nanoscale structures such as quantum dots and wires. 2,3 New applications for selenium may emerge. Techniques for nanowire fabrication include nanofabrication, 4 electrodeposition of metallic wires into pores and tracketched polymer membranes, 5,6 nanowire formation using self-organized nanoholes of anodically oxidized alumina, 7,8 and electron beam lithography. 9-11 A review on noval methods of nanoscale wire formation has been published recently. 12

Role of proteins in controlling selenium nanoparticle size

“…Combined with the results described here, those findings point to a complex and important role for proteins in biological and chemical Se(0) nanoparticle formation. Taken together, our results and previously published ones (Abdelouas et al 2000, Brown 1992, 1997, Kaur et al 2009 strongly suggest that proteins may play a major role in controlling the characteristics of NPs from biological or chemical origin. While the ability to control size and shape using proteins may provide a basis for exploring the use of biomolecules in the synthesis of SeNPs at larger than laboratory scale, it also warrants continued and targeted research into the mechanism of binding of these protein to the surface of NPs.…”

“…Our approach was to assay for the association of proteins to biogenic SeNPs. The assumption inherent in this approach is that proteins involved in nanoparticle formation are tightly associated with the produced NPs (Abdelouas et al 2000, Arakaki et al 2003, Aryal and Benson 2007, Brown 1992, Sano and Shiba 2003, Lower et al 2008. The assay involved growing E. coli bacteria in the presence of selenite until the appearance of a brick red colour representative of the presence of Se (0) and associated proteins were then collected by lysing the cells via ultrasonication and centrifuging the lysate through an 80% sucrose solution leading to four fractions (figure S5 available at stacks.iop.org/Nano/22/195605/mmedia).…”

“…Several studies provide evidence that proteins might play a key role in the nucleation and crystal growth of bacteriogenic metal NPs. A bacterial protein-cytochrome c 3 -was found to reduce selenate (SeO 2− 4 ) in aqueous solution leading to the formation of one-dimensional chain-like aggregates of monoclinic selenium nanoparticles (SeNPs) (Abdelouas et al 2000). Secondly, in magnetosomes of the magnetotactic bacterium, Magnetospirillum magneticum AMB-1, membrane proteins are tightly bound to the magnetic NPs (Gorby et al 1988, Leinfelder et al 1988, Tanaka et al 2006 and single proteins (Mms6 and BSA) were shown to be able to control the shape of the final particles (Arakaki et al 2003, Kaur et al 2009.…”

“…The most significant of which are that they do not yield the narrow size distributions (size variation of less than 5%) (Jeong and Xia 2005) that are important for industrial applications and that they produce particles that are subject to extreme photocorrosion (Dimitrijevic and Kamat 1988). In order to overcome the limitations of the previous techniques (high temperature, high pressure or use of catalysts), biologically based, semi-synthetic methods have been explored to produce nanomaterials (Abdelouas et al 2000).…”

A bacterial process for selenium nanosphere assembly

“…A number of studies have also taken advantage of biomolecules to generate Se nanoparticles in vitro. For example, Abdelouas et al (44) have used reduced cytochrome c to synthesize Se nanowires at room temperature. More recently, Zhang et al (45) synthesized t-Se nanowires using β-carotene as an in situ soft template.…”