Authors: D. Griffiths, W. Bernt, P. Hole, J. Sullivan, A. Malloy, B. Carr
Affilation: NanoSight USA, United States
Pages: 4 - 7
Keywords: zeta, potential, nanoparticle, electrophoresis, surface
A novel addition to a technique for the analysis of nanoparticles in a suspension is described. The Nanoparticle Tracking Analysis (NTA) technique visualizes then sizes individual nanoparticles, based on their Brownian motion. Unlike classical light scattering techniques, NTA allows nanoparticles to be sized on a particle-by-particle basis. This results in a higher resolution and therefore a better understanding of polydispersity than ensemble methods such as dynamic light scattering and it also yields directly a measurement of count and concentration. This paper introduces an extension of the technique in combination with an electrophoresis system to provide measurement of zeta potential on a particle-by-particle basis. This may be viewed as a development of traditional microelectrophoresis, with full automation of the particle tracking and electrophoretic mobility measurements and extended to particles as small as 10nm, depending on material type. The NTA-based measurement provides not just the average zeta potential of the whole sample, but a direct measurement of the values for each particle. This augments the almost ubiquitous light scattering measurement techniques for zeta potential on the market with an additional dimension of information. The technique has been shown to be able to differentiate between subpopulations in a heterogeneous mixture.