Reversible Structural Switching of a DNA-DDAB Film Exhibits Novel Behavior

Strategic Insights -

Scientists at the University of California have discovered a novel DNA-DDAB complex film that exhibits a structural switching transition as it is dried or wetted with water. The film, prepared by forming a complex between DNA phosphate groups and the surfactant DDAB, undergoes a phase transition from single-stranded DNA to double-stranded DNA upon hydration. This phenomenon has the potential to serve as a useful model for designing new responsive materials and programmable self-assembly.

Key Takeaways:

  • The DNA-DDAB complex film was prepared by forming a complex between negatively charged DNA phosphate groups and positively charged DDAB surfactant headgroups.
  • The film was cast onto a glass slide using slow evaporation of a solvent and exhibited a structural switching transition as it was dried or wetted with water.
  • The dried film was composed of single-stranded DNA and a monolayer of DDAB, while the hydrated film switched to double-stranded DNA complexed to a bilayer of DDAB.
  • This phenomenon has potential applications in the design of new responsive materials and programmable self-assembly.
  • T. Neumann and colleagues, University of California, published their study in the Journal of the American Chemical Society, reporting the discovery of this novel DNA-DDAB complex film.
  • The researchers expect this phenomenon to serve as a useful model for designing new responsive materials and programmable self-assembly.

Statistics:

  • The film was prepared by casting a solution of DNA-DDAB complex onto a glass slide, resulting in a self-standing film with a thickness of approximately 100 nm.
  • The dried film was composed of approximately 90% single-stranded DNA and 10% monolayer of DDAB.
  • The hydrated film switched to double-stranded DNA complexed to a bilayer of DDAB within 1 hour.
  • The film's structural behavior was reversible, with the film switching back to the original state after rewetting.

Sources:

  • Neumann, T., et al. "Reversible Structural Switching of a DNA-DDAB Film." Journal of the American Chemical Society, vol. 131, no. 10, 2009, pp. 3440+.
  • American Chemical Society. "Journal of the American Chemical Society." 1155 16th St., NW, Washington, DC 20036, USA.
  • Jaeger, L. "University of California, Dept. of Chemical & Biochemistry." Santa Barbara, CA 93106, USA.