Large-scale
and morphologically controlled self-assembled λ-DNA
networks were successfully constructed by the synergistic effect of
a DC electric field. The effect of DNA concentration, direction, and
intensity of the electric field, even the modification of the mica
surface using Mg2+ on the characteristics of the as-prepared
DNA networks, were investigated in detail by atomic force microscopy
(AFM). It was found that the horizontal electric field was more advantageous
to the formation of DNA networks with more regular structures. At
the same concentration, the height of DNA network was not affected
significantly by the intensity change of the horizontal electric field.
The modification of Mg2+ on mica surface increased the
aggregation of DNA molecules, which contributed to the morphological
change of the DNA networks. Furthermore, DNA molecules were obviously
stretched in both horizontal and vertical electric fields at low DNA
concentrations.