Figure 1.

Schematic illustrations of (a) ssDNA passing through a cylindrical nanochannel and (b) a coarse-grained bead-spring model of the polymer chain. The longitudinal electric field, E_z, results in electrophoresis of the negatively charged DNA and an EOF due to the wall surface charges. The surface of the nanochannel is either negatively or positively charged associated with the ζ-potential. A nonconstant viscosity layer is known to exist very near the surface, and EDLs affect the EOF flow pattern. To see this figure in color, go online.