[RSC Advances] Tris Base Assisted Synthesis of Monodispersed Citrate-capped Gold Nanospheres with Tunable Size
writer：Xuefei Lu, Anirban Dandapat, Youju Huang,* Lei Zhang, Liwei Dai, Yoe Sasson, Jiawei Zhang, Tao Chen*
keywords：Au NPs, Polymeric surfactants
source：期刊
specific source：RSC Advances, 2016, 6, 60916-60921
Issue time：2016年
We demonstrate a simple and
effective method to obtain highly pure and monodispersed spherical gold
nanoparticles (AuNPs) with a narrow size distribution (RSD ~ 4-7%) in aqueous
medium. The synthetic strategy involves the addition of HAuCl4 in
preheated sodium citrate (SC) solution followed by addition of tris base (TB)
which simultaneously acts as stabilizer, mild reducing agent and pH-mediator. A
significant improvement in the uniformity and size tenability of the Au
nanospheres has been observed by using subtle amounts of TB in contrast to the
conventional way of using only SC. It is their synergistic effect that controls
the amount of nuclei by heating SC, and then controlling the rate of nucleation
and growth by introducing TB, which successfully produced particles with
uniform morphology. Notably, HAuCl4 solution was added in multiple
steps to significantly improve the quality of the NPs in comparison to the
addition of whole HAuCl4 solution at one time. In this way, we have
successfully developed spherical NPs with sizes ranging from 20 to 115 nm,
which efficiently improve the classical Turkevich/Frens method with respect to
the reproducibility and uniformity of the NP''''''''s size and shape. A representative
set of NPs was controlled to spontaneously self-assemble into a monolayer
assembly at a hexane/water interface. This will allow them to be used as a
promising and outstanding candidate for application in the field of
spectroscopy, catalysis, optoelectronic nanodevices and biosensors.