• Controlled self-assembly of lambda-DNA networks with the synergistic effect of a DC electric field

      Gao, Mingyan; Hu, Jing; Wang, Ying; Liu, Mengnan; Wang, Jianfei; Song, Zhengxun; Xu, Hongmei; Hu, Cuihua; Wang, Zuobin; (American Chemical Society, 2019-11-04)
      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.
    • Controlled self-assembly of λ-DNA networks with the synergistic effect of a DC electric field

      Gao, Mingyan; Hu, Jing; Wang, Ying; Liu, Mengnan; Wang, Jianfei; Song, Zhengxun; Xu, Hongmei; Hu, Cuihua; Wang, Zuobin; (American Chemical Society, 2019-11-04)
      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.
    • Imaging the substructures of individual IgE antibodies with atomic force microscopy

      Hu, Jing; Gao, Mingyan; Wang, Ying; Liu, Mengnan; Wang, Jianfei; Li, Jiani; Song, Zhengxun; Chen, Yujuan; Wang, Zuobin (American Chemical Society, 2019-10-29)
      The interaction between antibodies and substrates directly affects its conformation and thus its immune function. Therefore, it is desirable to study the structure of antibodies at the single molecule level. Herein, the substructures of Immunoglobulin E (IgE) on solid surfaces were investigated. For this purpose, the tapping-mode atomic force microscopy (AFM) was applied to observe the individual IgE substructures adsorbed onto Mg2+ and Na+ modified mica substrates in air. As expected, the AFM images revealed that the IgE antibodies exhibited different conformations on the surface of mica substrate, consisting of the four basic orientations: three domain, two equivalent domain, two unequal domain and single domain morphologies. Moreover, the differences of the different orientations in single IgE antibodies were also identified clearly.