Understanding of the SizeControl of BiocompatibleGold Nanoparticles in Millifluidic Channels.

The size control of gold nanoparticles synthesized insurfactantfree water with a continuous flow mode was elucidated and used toproduce higher concentration (3 mM) of stabilized gold nanoparticles.The originality of the synthesis was to finely modulate the initialpH of the reducing agent instead of the gold precursor to modify thekinetic of the reaction. The acceleration of the kinetic (∼1s) prevents the modification of the gold precursors ensuring the controlof the final size (from 3 to 25 nm) of the nanoparticles with a lowpolydispersity for aqueous surfactant free solution. The accuratemeasure of the size distribution by small angle X-ray scattering wascombined to the use of a model based on the coupling of nucleationand growth equations together with a progressive injection of monomers.The results on the final state show that the size of the nanoparticlesis indeed controlled by the kinetic of reduction of gold atoms. Amillifluidic setup equipped with a homemade mixer offers a robustway of rapid mixing to obtain a reproducible production of large amountsof nanoparticles. [ABSTRACT FROM AUTHOR]