title: Emulsions-directed assembly of gold nanoparticles to molecularly-linked and size-controlled spherical aggregates.
abstract: Aggregation of gold nanoparticles into soluble spherical assemblies using bi-functional ligands i.e., dithiols has recently been demonstrated but with limited control over the size of such assemblies. Herein, we report a new approach to further control the size of water dispersible spherical assemblies by confining gold nanoparticles in tiny oil droplets in water (oil-in-water emulsions) followed by their cross-linking with alkanedithiols. By controlling the size of the oil droplets and the concentration of nanoparticles, the size of spherical aggregates can be controlled from 20 to 400 nm. Cryo-TEM micrographs confirm the formation of covalently-linked soluble spherical nanoparticle assemblies within the oil emulsions in water. Such size-controlled nanoparticle assemblies may have several potential applications including those in gas sensors, controlled delivery, and optical coatings.
authors.affiliation: LUMS School of Science & Engineering (SSE), D.H.A., Lahore Cantt 54792, Pakistan. ihussain@lums.edu.pk
authors.forename: Irshad
authors.initials: I
authors.lastname: Hussain
authors.forename: Haifei
authors.initials: H
authors.lastname: Zhang
authors.forename: Mathias
authors.initials: M
authors.lastname: Brust
authors.forename: Justas
authors.initials: J
authors.lastname: Barauskas
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Cooper
mesh_terms: D004655:Emulsions / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D016062:Porosity
chemical_list: D004655:Emulsions; D006046:Gold