Simultaneous sizing and electrophoretic mobility measurement of sub-micron particles using Brownian motion.

ABSTRACT: The size and surface chemistry of micron scale particles are of fundamental importance in studies of biology and air particulate pollution. However, typical electrophoretic measurements of these and other sub-micron scale particles (300 nm-1 μm) cannot resolve size information within heterogeneous mixtures unambiguously. Using optical microscopy, we monitor electrophoretic motion together with the Brownian velocity fluctuations - using the latter to measure size by either the Green-Kubo relation or by calibration from known size standards. Particle diameters are resolved to ±12% with 95% confidence. Strikingly, the size resolution improves as the particle size decreases due to the increased Brownian motion. The sizing ability of the Brownian assessed electrophoresis method described here c

SUBMITTER: Palanisami A 

PROVIDER: S-EPMC3070742 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature