Analytical separation of polystyrene nanospheres by capillary electrophoresis

Abstract

Abstract The analytical capillary electrophoretic separation of polystyrene nanospheres is reported. Although these particles are negatively charged and possess intrinsic mobilities, their Separations are based upon particle size with the smallest particles having the highest velocity through the capillary. Pretreatment of the capillary with a cationic surfactant is necessary to observe these Separations. Interestingly, particles larger than about 700 nm in diameter cannot be observed to move through a 50‐μm‐ i.d. capillary, whereas particles as small as 39 nm in diameter can be resolved in this system. In contrast to normal electrophoretic Separations, the mechanism of this process appears to be that of particlexapillary wall interaction as mediated by the adsorbed surfactant.