Figure 4
TEM characterization of the Sep/DNA bionanocomposite (A–C). (D,E) TEM images of a single molecule of Sep/DNA. The DNA bound to the sepiolite at the edge of the nanofiber and on its external surface. Nanofibers can be completely coated with DNA, but some DNA molecules are bound at one of their extremities, and two different nanofibers can be linked by a DNA plasmid. Reaction conditions: 1 mg/ml sepiolite, 10 mM Tris-HCl, pH = 7.5, 5 mM MgCl2, and 50 ng·μl−1 plasmid DNA (5.7 kb). (G) Scheme illustrating the DNA-sepiolite bionanocomposite resulting from the sepiolite interaction with linear DNA. It is also show the silanol groups (Si-OH) present at the external surface of the sepiolite fibers which are in hydrogen bonding interaction with nitrogenated bases at the DNA chains.
