title: Multidimensional analysis of nanoparticles with highly disperse properties using multiwavelength analytical ultracentrifugation.
abstract: The worldwide trend in nanoparticle technology toward increasing complexity must be directly linked to more advanced characterization methods of size, shape and related properties, applicable to many different particle systems in science and technology. Available techniques for nanoparticle characterization are predominantly focused on size characterization. However, simultaneous size and shape characterization is still an unresolved major challenge. We demonstrate that analytical ultracentrifugation with a multiwavelength detector is a powerful technique to address multidimensional nanoparticle analysis. Using a high performance optical setup and data acquisition software, information on size, shape anisotropy and optical properties were accessible in one single experiment with unmatched accuracy and resolution. A dynamic rotor speed gradient allowed us to investigate broad distributions on a short time scale and differentiate between gold nanorod species including the precise evaluation of aggregate formation. We report how to distinguish between different species of single-wall carbon nanotubes in just one experiment using the wavelength-dependent sedimentation coefficient distribution without the necessity of time-consuming purification methods. Furthermore, CdTe nanoparticles of different size and optical properties were investigated in a single experiment providing important information on structure-property relations. Thus, multidimensional information on size, density, shape and optical properties of nanoparticulate systems becomes accessible by means of analytical ultracentrifugation equipped with multiwavelength detection.
authors.affiliation: Institute of Particle Technology (LFG), Friedrich-Alexander University Erlangen-Nürnberg (FAU) , Cauerstr. 4, 91058 Erlangen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Walter
authors.forename: Konrad
authors.initials: K
authors.lastname: Löhr
authors.forename: Engin
authors.initials: E
authors.lastname: Karabudak
authors.forename: Wieland
authors.initials: W
authors.lastname: Reis
authors.forename: Jules
authors.initials: J
authors.lastname: Mikhael
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Peukert
authors.forename: Wendel
authors.initials: W
authors.lastname: Wohlleben
authors.forename: Helmut
authors.initials: H
authors.lastname: Cölfen
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D043942:Nanotubes / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D010316:Particle Size; D059629:Signal-To-Noise Ratio; D013691:Tellurium / Q000737:chemistry; D014461:Ultracentrifugation / Q000379:methods*
chemical_list: D019187:Cadmium Compounds; D037742:Nanotubes, Carbon; D006046:Gold; D013691:Tellurium; C028337:cadmium telluride
keywords: analytical ultracentrifugation (AUC) with multiwavelength detection; carbon nanotubes; gold nanorods; nanoparticles; particle size distribution; speed ramps