Fluidic Manufacture of Star‐Shaped Gold Nanoparticles

Abstract

Star-shaped gold nanoparticles (StarAuNPs) are extremely attractive nanomaterials, characterized by localized surface plasmon resonance which could be potentially employed in a large number of applications. However, the lack of a reliable and reproducible synthetic protocols for the production of StarAuNPs is the major limitation to their spreading. For the first time, here we present a robust protocol to manufacture reproducible StarAuNPs by exploiting a fluidic approach. Star-shaped AuNPs have been synthesized by means of a seed-less protocol, employing ascorbic acid as reducing agent at room temperature. Moreover, the versatility of the bench-top microfluidic protocol has been exploited to afford hydrophilic, hydrophobic and solid-supported engineered StarAuNPs, by avoiding intermediate NP purifications.

Design and synthesis of gold nanostars-based SERS nanotags for bioimaging applications

“…Microfluidic systems offer accurate control of various experimental parameters, such as sample volume, flow rate, mixing velocity, reaction time and temperature, providing a significantly more precise way to optimize the physical properties and hence imaging performance of SERS nanoprobes [78]. As such, microfluidic systems with different flow profiles, specifically continuous and segmented (or droplet) flows, have been used to produce a range of plasmonic nanostructures including gold nanostars which have been used as plasmonic cores of SERS nanoprobes [80][81][82][83][84][85].…”

Bespoke nanostars: synthetic strategies, tactics, and uses of tailored branched gold nanoparticles

“…145,146 Silvestri et al demonstrated millifluidic synthesis of gold nanostars through a seedless, silver-mediated synthesis. 143 The final nanostar morphology was highly influenced by flow rate; slower flux rate caused inefficient mixing resulting in polydisperse product while higher flux rate yielded large nanocrystals and clusters. Another group obtained star-like gold nanosystem intermediates by adjusting the pH of the reaction through increased flow rate of an alkaline growth solution.…”

Anisotropic Gold Nanoparticles in Biomedical Applications

“…Each single batch can be different from the others as too many parameters control the morphology, size and stability of NPs. In order to overcome these issues a microfluidic protocol was developed to produce, for the first time, multibranched gold nanoparticles at room temperature and avoiding the use of toxic template ( Figure 7 ) [ 56 ]. The methodology is based on the accurate mixing of gold precursor (HAuCl 4 ) and ascorbic acid as reducing agent, in a proper ratio and with a flux fixed at 5 mL/min, while the fine control of the morphology was achieved by adding silver nitrate.…”

“…Right: ( A ) TEM image of a single multibranched gold nanoparticle immobilized on titania; ( B ) HR-TEM image of a single branch interacting with a titania. Reproduced from [ 56 ] with permission from John Wiley and Sons.…”