Analytical and Bioanalytical Chemistry

, 395:1651

The size distribution of 'gold standard' nanoparticles

Authors

  • Ralf Bienert
    • BAM Federal Institute for Materials Research and Testing
  • Franziska Emmerling
    • BAM Federal Institute for Materials Research and Testing
    • BAM Federal Institute for Materials Research and Testing
Original Paper

DOI: 10.1007/s00216-009-3049-5

Cite this article as:
Bienert, R., Emmerling, F. & Thünemann, A.F. Anal Bioanal Chem (2009) 395: 1651. doi:10.1007/s00216-009-3049-5

Abstract

The spherical gold nanoparticle reference materials RM 8011, RM 8012, and RM 8013, with a nominal radius of 5, 15, and 30 nm, respectively, have been available since 2008 from NIST. These materials are recommended as standards for nanoparticle size measurements and for the study of the biological effects of nanoparticles, e.g., in pre-clinical biomedical research. We report on determination of the size distributions of these gold nanoparticles using different small-angle X-ray scattering (SAXS) instruments. Measurements with a classical Kratky type SAXS instrument are compared with a synchrotron SAXS technique. Samples were investigated in situ, positioned in capillaries and in levitated droplets. The number-weighted size distributions were determined applying model scattering functions based on (a) Gaussian, (b) log-normal, and (c) Schulz distributions. The mean radii are 4.36 ± 0.04 nm (RM 8011), 12.20 ± 0.03 nm (RM 8012), and 25.74 ± 0.27 nm (RM 8013). Low polydispersities, defined as relative width of the distributions, were detected with values of 0.067 ± 0.006 (RM 8011), 0.103 ± 0.003, (RM 8012), and 0.10 ± 0.01 (RM 8013). The results are in agreement with integral values determined from classical evaluation procedures, such as the radius of gyration (Guinier) and particle volume (Kratky). No indications of particle aggregation and particle interactions—repulsive or attractive—were found. We recommend SAXS as a standard method for a fast and precise determination of size distributions of nanoparticles.

https://static-content.springer.com/image/art%3A10.1007%2Fs00216-009-3049-5/MediaObjects/216_2009_3049_Figa_HTML.gif
Figure 1

A suspension of gold nanoparticles with a nominal diameter of 10 nm is positioned in a trap (acoustic levitator) for SAXS analysis with synchrotron radiation (droplet diameter is 2 mm). The measured scattering intensities (black line in right hand figure) are interpreted in terms of model functions (red line) for precise determination of the particles’ size distribution. Thank you.

Keywords

Small-angle scatteringReference materialsMetrologyNanoparticles

Copyright information

© Springer-Verlag 2009