title: Shape and color of au nanoparticles follow biocatalytic processes.
abstract: The NAD(P)H-mediated growth of Au nanoparticles (NPs) in the presence of ascorbic acid, AuCl4-, and cetyltrimethylammonium bromide leads to the formation of shaped NP structures consisting of dipods, tripods, and tetrapods. The shaped particles exhibit a red-shifted plasmon absorbance at lambda = 680 nm, consistent with the existence of a longitudinal plasmon exciton. High-resolution transmission electron microscopy analysis of the tripod and tetrapod structures reveals directional growth along the <211> and <010> directions, respectively. The shaped Au NPs could be generated by a biocatalytic process using alcohol dehydrogenase, NAD+, and ethanol, and the resulting blue color provides a colorimetric test for ethanol.
authors.affiliation: Institute of Chemistry and The Unit for Nanoscopic Characterization, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
authors.forename: Bella
authors.initials: B
authors.lastname: Shlyahovsky
authors.forename: Inna
authors.initials: I
authors.lastname: Popov
authors.forename: Valeri
authors.initials: V
authors.lastname: Pavlov
authors.forename: Itamar
authors.initials: I
authors.lastname: Willner
mesh_terms: D001205:Ascorbic Acid; D002384:Catalysis; D003461:Crystallography; D017612:Gold Compounds; D008854:Microscopy, Electron; D008958:Models, Molecular; D009243:NAD / Q000737:chemistry*; D009249:NADP / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D017612:Gold Compounds; D009243:NAD; C038016:gold chloride; D009249:NADP; D001205:Ascorbic Acid