Continuous flow technology for the photochemical synthesis of spherical gold nanoparticles

Gold nanoparticles (Au NPs) are used in a wide range of applications because of their localized surface plasmon resonance (LSPR), leading to shape- and size-dependent optical properties. The photochemical generation of gold NPs has emerged as a potential alternative to the wellknown Turkevitch method since it offers a spatial and temporal control.
We present herein a continuous flow process for the controlled photochemical synthesis of spherical gold NPs with a novel water-soluble acylphosphinate photoinitiator. The implementation of a continuous flow setup overcomes issues related to batch synthesis, namely poor mixing efficiency, poor light penetration and inefficient control of the local parameters. After optimization, the NPs size is only dictated by the irradiation time.