title: Surfactant-Free Shape Control of Gold Nanoparticles Enabled by Unified Theoretical Framework of Nanocrystal Synthesis.
abstract: Gold nanoparticles have unique properties that are highly dependent on their shape and size. Synthetic methods that enable precise control over nanoparticle morphology currently require shape-directing agents such as surfactants or polymers that force growth in a particular direction by adsorbing to specific crystal facets. These auxiliary reagents passivate the nanoparticles' surface, and thus decrease their performance in applications like catalysis and surface-enhanced Raman scattering. Here, a surfactant- and polymer-free approach to achieving high-performance gold nanoparticles is reported. A theoretical framework to elucidate the growth mechanism of nanoparticles in surfactant-free media is developed and it is applied to identify strategies for shape-controlled syntheses. Using the results of the analyses, a simple, green-chemistry synthesis of the four most commonly used morphologies: nanostars, nanospheres, nanorods, and nanoplates is designed. The nanoparticles synthesized by this method outperform analogous particles with surfactant and polymer coatings in both catalysis and surface-enhanced Raman scattering.
authors.affiliation: Department of Radiology and Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, NY, 10065, USA.|Department of Chemistry, Hunter College and the Graduate Center, City University of New York, NY, 10016, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Wall
authors.affiliation: Department of Radiology and Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, NY, 10065, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Harmsen
authors.affiliation: Department of Mathematics, University of Washington, Seattle, WA, 98103, USA.
authors.forename: Soumik
authors.initials: S
authors.lastname: Pal
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Hunter College, City University of New York, NY, 10065, USA.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Arianna
authors.affiliation: Department of Chemistry, City College and the Graduate Center, City University of New York, NY, 10031, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Lombardi
authors.affiliation: Department of Chemistry, Hunter College and the Graduate Center, City University of New York, NY, 10016, USA.
authors.forename: Charles Michael
authors.initials: CM
authors.lastname: Drain
authors.affiliation: Department of Radiology and Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, NY, 10065, USA.|Weill Cornell Medical College of Cornell University, NY, 10065, USA.|Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Moritz F
authors.initials: MF
authors.lastname: Kircher
keywords: crystal growth; gold nanorods; nanoparticles; shape-control; surfactant-free