Controlled Self-Assembly of λ-DNA Networks with the Synergistic Effect of DC Electric Field

Large-scale and morphologically controlled self-assembled λ-DNA networks were successfully constructed by the synergistic effect of DC electric field. The effect of DNA concentration, direction and intensity of the electric field, even the modification of the mica surface using Mg 2+ 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 Mg 2+ 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. Statement of significance Through the synergistic effect of DC electric field, a series of large-scale and morphologically controlled self-assembled λ-DNA networks were successfully fabricated. We found that the horizontal electric field was more advantageous to the formation of DNA networks with more regular structures. At the same concentration of DNA solution, the height of DNA network was not affected significantly by the intensity change of the horizontal electric field. The modification of Mg 2+ on mica surface increased the aggregation of DNA molecules, which contributed to the morphological change of the DNA networks. We suggest this study will promote the understanding on the preparation of controllable self-assembled λ-DNA networks and the application of DNA networks.