Synthesis of ultra-small cysteine-capped gold nanoparticles by pH switching of the Au(I)-cysteine polymer

PAULA S. CAPPELLARI; BUCETA, DAVID; GUSTAVO M. MORALES; CÉSAR A. BARBERO; M. SERGIO MORENO; GIOVANETTI, L. J.; JOSE MARTIN RAMALLO LOPEZ; F. G. REQUEJO; ALDO F. CRAIEVICH; GABRIEL A. PLANES

JOURNAL OF COLLOID AND INTERFACE SCIENCE

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: San Diego; Año: 2015 vol. 441 p. 17 - 24

0021-9797

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.