Figure 10.

Schematic representations of the ssDNA transport mechanism in a nanofluidic channel resulting from the LD simulations. The DNA chain experiences a repulsive (a and b) or attractive (c and d) forces in the radial direction caused by negative or positive ζ-potentials, respectively. Depending on the ion concentration, a strong electric force acts on the molecule in the EDL. (a and b) Due to the negative ζ-potential, the channel surface repels the negatively charged DNA toward the center, the EOF field causes intramolecular interactions in the polymer chain, and the velocity gradient at lower ion concentrations results in stretching of the polymer structure as shown in (b). (c and d) The positive ζ-potential attracts the DNA to the channel surface and the EOF velocity gradient deforms the molecule in a dilute solution. As a result, the polymer structure is compressed as shown in (d). To see this figure in color, go online.