Citrate Coordination and Bridging of Gold Nanoparticles: The Role of Gold Adatoms in AuNP Aging
Year: 2020
Type: article
Abstract: Gold nanoparticles used in many types of nanostructure are mostly stabilized by citrate ligands. Fully understanding their dynamic surface chemistry is thus essential for applications, particularly since aging is frequently a problem. Using surface-enhanced Raman spectroscopy in conjunction with density functional theory calculations, we are able to determine Au-citrate coordination in liquid with minimal invasiveness. We show that citrate coordination is mostly bidentate and simply controlled by its protonation state. More complex binding motifs are caused by interfering chloride ions and gold adatoms. With increasing age of stored gold nanoparticle suspensions, gold adatoms are found to move atop the Au facets and bind to an additional terminal carboxylate of the citrate. Aged nanoparticles are fully refreshed by removing these adatoms, using etching and subsequent boiling of the gold nanoparticles.
Source: ACS Nano
Institution: University of Cambridge
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,000
Awards: Cucurbitrils for Hardwired Optical and Electronic Self-assembly, EPSRC Centre for Doctoral Training (CDT) in Sensor Technologies and Application, Open Lab Instrumentation, Soft NanoPhotonics Programme Grant (sNaP), G389153754, G4391376358, Raman Nanotheranostics - RaNT - developing the targeted diagnostics and therapeutics of the future by combining light and functionalised nanoparticles, Nano-Optics to controlled Nano-Chemistry Programme Grant (NOtCH)
OpenAlex ID: W3035551885