challenges of electrophoretic mobility measurements
electrophoretic mobility is commonly studied in ensemble, which has an inherent limitation by averaging out processes which can be very diverse from particle to particle. Therefore, studying single-particle electrophoresis may open the door to intriguing new results.
At the single-particle level, measuring electrophoretic mobility requires:
- Tracking the motion of particles with sufficient spatial and temporal resolution
This is where optical methods may be of help (@faez2016Nanocapillary electrokinetic tracking for monitoring charge fluctuations on a single nanoparticle). Especially, one can do nanoparticle tracking in hollow optical fibers, which has the advantage of both high-localization accuracy (sub-wavelength) and high frame-rates (@faez2015Fast, Label-Free Tracking of Single Viruses and Weakly Scattering Nanoparticles in a Nanofluidic Optical Fiber).
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