Jason M. Thomas, Hua-Zhong Yu, and Dipankar Sen Journal of the American Chemical Society Article ASAP
These researchers engineered a DNA sequence that can function as a three-way nano junction, or "switch," in response to chemical stimulus. Upon introduction of of Hg2+ ions, T-T mismatches bind to ion centers and causes the DNA strand to bend. They measure this change using osmium staining to check for the binding of mercury as well as FRET imaging. They also use electron-hole transport efficiency as a measure of the electronic nature of the switch drawing conclusions that the switch is less conductive in ints open conformation.