title: Water-dispersible tryptophan-protected gold nanoparticles prepared by the spontaneous reduction of aqueous chloroaurate ions by the amino acid.
abstract: The synthesis of water-dispersible amino-acid-protected gold nanoparticles by the spontaneous reduction of aqueous chloroaurate ions by tryptophan is described. Water-dispersible gold nanoparticles may also be obtained by the sequential synthesis of the gold nanoparticles by borohydride reduction of chloroauric acid followed by capping with tryptophan. Comparison of the proton NMR spectroscopic signatures from the tryptophan-protected gold nanoparticles obtained by the two processes indicated that the indole group in tryptophan is responsible for reduction of the aqueous chloroaurate ions. The reduction of the metal ions is accompanied by oxidative polymerization of the indole group of the tryptophan molecules and, consequently, some degree of cross-linking of the gold nanoparticles.
authors.affiliation: Materials Chemistry Division, National Chemical Laboratory, Pune 411 008, India.
authors.forename: Pr
authors.initials: P
authors.lastname: Selvakannan
authors.forename: Saikat
authors.initials: S
authors.lastname: Mandal
authors.forename: Sumant
authors.initials: S
authors.lastname: Phadtare
authors.forename: Anand
authors.initials: A
authors.lastname: Gole
authors.forename: Renu
authors.initials: R
authors.lastname: Pasricha
authors.forename: S D
authors.initials: SD
authors.lastname: Adyanthaya
authors.forename: Murali
authors.initials: M
authors.lastname: Sastry
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D017612:Gold Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D036103:Nanotechnology / Q000379:methods*; D010084:Oxidation-Reduction; D010316:Particle Size; D014364:Tryptophan / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D001672:Biocompatible Materials; D002712:Chlorides; D017612:Gold Compounds; D014867:Water; D006046:Gold; D014364:Tryptophan; C024568:gold tetrachloride, acid