New Paper on the Size-Controlled Synthesis of Sub-10-nanometer Citrate-Stabilized Gold Nanoparticles Published in Chemistry of Materials.

The development of synthetic strategies for the controlled production of small Au nanoparticles (Au NPs) with accessible surface is of crucial important for the design of the final selectivity, activity and compatibility of Au NPs, especially in those (bio)applications where size is a critical parameter . In this work, we report a new synthetic method for the production of highly monodisperse, biocompatible and functionalizable sub-10-nm citrate-stabilized gold nanoparticles following a kinetically controlled seeded-growth strategy. We found how the use of traces of tannic acid together with an excess of sodium citrate during nucleation is fundamental in the formation of a high number of small ∼3.5 nm Au seeds. These seeds can be further grown, with nanometric resolution, to produce Au NPs with a precise control over their sizes between 3.5 and 10 nm. These samples allow studying the size-dependent optical properties in the small transition size regime lying between clusters and nanoparticles. The work has now been published in Chemistry of Materials under the title “Size-Controlled Synthesis of Sub-10-nanometer Citrate-Stabilized Gold Nanoparticles and Related Optical Properties.“