title: Synthesis of ultra-small cysteine-capped gold nanoparticles by pH switching of the Au(I)-cysteine polymer.
abstract: We report a synthetic approach for the production of ultra-small (0.6 nm) gold nanoparticles soluble in water with a precise control of the nanoparticle size. Our synthetic approach utilizes a pH-depending Au-cysteine polymer as a quencher for the AuNPs grown. The method extends the synthetic capabilities of nanoparticles with sizes down to 1 nm. In addition to the strict pH control, the existence of free -SH groups present in the mixture of reaction has been observed as a key requirement for the synthesis of small nanoparticles in mild conditions. UV-Vis, SAXS, XANES, EXAFS and HR-TEM, has been used to determinate the particle size, characterization of the gold precursor and gold-cysteine interaction.
authors.affiliation: Universidad Nacional de Río Cuarto, Ruta Nac. 36, Km 601, Río Cuarto, Córdoba, Argentina.
authors.forename: Paula S
authors.initials: PS
authors.lastname: Cappellari
authors.affiliation: Laboratorio de Magnetismo y Nanotecnología, Instituto de Investigacións Tecnológicas, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain(1).
authors.forename: David
authors.initials: D
authors.lastname: Buceta
authors.affiliation: Universidad Nacional de Río Cuarto, Ruta Nac. 36, Km 601, Río Cuarto, Córdoba, Argentina.
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: Morales
authors.affiliation: Universidad Nacional de Río Cuarto, Ruta Nac. 36, Km 601, Río Cuarto, Córdoba, Argentina.
authors.forename: Cesar A
authors.initials: CA
authors.lastname: Barbero
authors.affiliation: Centro Atómico Bariloche, Av. Bustillo 9500, 8400 San Carlos de Bariloche, Rio Negro, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Sergio Moreno
authors.affiliation: INIFTA, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata - CONICET, Diagonal 113 y 64, 1900 La Plata, Argentina.
authors.forename: Lisandro J
authors.initials: LJ
authors.lastname: Giovanetti
authors.affiliation: INIFTA, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata - CONICET, Diagonal 113 y 64, 1900 La Plata, Argentina.
authors.forename: José Martín
authors.initials: JM
authors.lastname: Ramallo-López
authors.affiliation: INIFTA, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata - CONICET, Diagonal 113 y 64, 1900 La Plata, Argentina.
authors.forename: Felix G
authors.initials: FG
authors.lastname: Requejo
authors.affiliation: Institute of Physics, University of Sao Paulo, CEP 05508-900 Sao Paulo, SP, Brazil.
authors.forename: Aldo F
authors.initials: AF
authors.lastname: Craievich
authors.affiliation: Universidad Nacional de Río Cuarto, Ruta Nac. 36, Km 601, Río Cuarto, Córdoba, Argentina. Electronic address: gplanes@exa.unrc.edu.ar.
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Planes
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers; D006046:Gold; D003545:Cysteine
keywords: Au–cysteine polymer; Cysteine; Gold nanoparticles