title: Comparative method evaluation for size and size-distribution analysis of gold nanoparticles.
abstract: Gold nanoparticles (GNPs) are popular colloidal substrates in various sensor, imaging, and nanomedicine applications. In separation science, they have raised some interest as a support for sample preparation. Reasons for their popularity are their low cost, ability for size-controlled synthesis with well-defined narrow nanoparticle size distributions, as well as straightforward surface functionalization by self-assembling (thiol-containing) molecules on the surface, which allows flexible introduction of functionalities for the selective capture of analytes. Most commonly, the method of first choice for size determination is dynamic light scattering (DLS). However, DLS has some serious shortcomings, and results from DLS may be misleading. For this reason, in this contribution several distinct complementary nanoparticle sizing methodologies were utilized and compared to characterize citrate-capped GNPs of different diameters in the range of 13-26 nm. Weaknesses and strengths of DLS, transmission electron microscopy, asymmetrical-flow field-flow fractionation and nanoelectrospray gas-phase electrophoretic mobility molecular analysis are discussed and the results comparatively assessed. Furthermore, the distinct GNPs were characterized by measuring their zeta-potential and surface plasmon resonance spectra. Overall, the combination of methods for GNP characterization gives a more realistic and comprehensive picture of their real physicochemical properties, (hydrodynamic) diameter, and size distribution.
authors.affiliation: Department of Analytical Chemistry, University of Vienna, Vienna, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hinterwirth
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Wiedmer
authors.forename: Maria
authors.initials: M
authors.lastname: Moilanen
authors.forename: Angela
authors.initials: A
authors.lastname: Lehner
authors.forename: Günter
authors.initials: G
authors.lastname: Allmaier
authors.forename: Thomas
authors.initials: T
authors.lastname: Waitz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lindner
authors.forename: Michael
authors.initials: M
authors.lastname: Lämmerhofer
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size
chemical_list: D006046:Gold
keywords: Asymmetrical-flow field-flow fractionation; Dynamic light scattering; Gold nanoparticles; Nanoelectrospray gas-phase electrophoretic mobility molecular analysis; Transmission electron microscopy