title: Coenzyme based synthesis of silver nanocrystals.
abstract: In this work we have carried out systematic studies to identify the critical role of a coenzyme (β-NADPH) to synthesize silver nanoparticle. Interestingly, both roles of reducing and stabilizing agents are played by β-NADPH. Nanoparticles obtained by this route exhibit a good crystallinity, a narrow size distribution and excellent stability in aqueous solution. The most advantageous points of this single-step environmentally friendly approach are that it takes place at nearly room temperature (20 °C), overcomes many limitations encountered in other biological methods (such as the restricted concentration of AgNO₃, maintenance and manipulation of microorganisms, preparing extracts and contamination from residual reactants), bypasses the use of surfactants or capping agents and does not necessitate pH adjustment. The nano-Ag were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, UV-vis, and energy-dispersive X-ray spectroscopy (EDX). DLS, TEM and XRD measurements showed the formation of nano-Ag with an average diameter of 20.77±0.67 nm. XRD studies confirmed the nanocrystalline nature of the silver particles. Zeta potential measurements revealed that the particles are surrounded with negatively charged groups (-41±5 mV) making them stable in an aqueous medium. The EDX spectrum of the silver nanoparticles confirmed the presence of elemental silver signal in high percentage. In addition to the easy and ecofriendly method of synthesis, β-NADPH can be regenerated by enzymatic means through glucose 6-phosphate dehydrogenase, potentially making the synthesis more cost effective.
authors.affiliation: Laboratoire de Génie Enzymatique et Cellulaire, UMR 6022 CNRS, Université de Technologie de Compiègne, BP 20529-60205 Compiègne Cedex, France. tanvirsh@utc.fr
authors.forename: Shazia
authors.initials: S
authors.lastname: Tanvir
authors.forename: Francois
authors.initials: F
authors.lastname: Oudet
authors.forename: Sylviane
authors.initials: S
authors.lastname: Pulvin
authors.forename: William A
authors.initials: WA
authors.lastname: Anderson
mesh_terms: D001709:Biotechnology / Q000379:methods*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D009249:NADP / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012834:Silver / Q000032:analysis / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction
chemical_list: D012834:Silver; D009249:NADP; D005954:Glucosephosphate Dehydrogenase