Stabilization of TiO2 nanoparticles in complex medium through a pH adjustment protocol

Environ Sci Technol. 2013 Jan 15;47(2):1057-64. doi: 10.1021/es3040736. Epub 2012 Dec 26.

Abstract

Preparing TiO(2) nanoparticle (NP) suspensions displaying well-defined and reproducible dispersion state is a key feature to perform relevant toxicity experiments for environmental, animal, or human concerns. Relying on the evolution of surface charge with pH, and interactions between nanoparticles in their medium, we developed an optimized dispersion protocol involving a pH adjustment before addition of bovine serum albumin (BSA). It yielded highly dispersed and stable concentrated stock suspensions of TiO(2) NP at pH 7. It was designed for four kinds of manufactured TiO(2) nanomaterials and can be extended to a wide range of TiO(2) NP. The suspensions studied here were characterized by small-angle X-ray scattering (SAXS), using a model quantitatively describing fractal aggregates. Results were correlated with dynamic light scattering (DLS) measurements. Moreover, the stability in a typical biological medium was assessed by diluting stock suspensions in Luria-Bertani (LB) medium. It resulted in highly dispersed and stable working suspensions. No sedimentation, followed by in situ DLS, was observed over 17 h for both the concentrated stock suspensions prepared according to the pH adjusted-BSA protocol and their dilution into LB medium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Hydrogen-Ion Concentration
  • Nanoparticles / chemistry*
  • Particle Size
  • Scattering, Small Angle
  • Serum Albumin, Bovine / chemistry*
  • Surface Properties
  • Titanium / chemistry*
  • X-Ray Diffraction

Substances

  • titanium dioxide
  • Serum Albumin, Bovine
  • Titanium