Electrochemical interrogation of conformational changes as a reagentless method for the sequence-specific detection of DNA

We report a strategy for the reagentless transduction of DNA hybridization into a readily detectable electrochemical signal by means of a conformational change analogous to the optical molecular beacon approach. The strategy involves an electroactive, ferrocene-tagged DNA stem-loop structure that self-assembles onto a gold electrode by means of facile gold-thiol chemistry. Hybridization induces a large conformational change in this surface-confined DNA structure, which in turn significantly alters the electron-transfer tunneling distance between the electrode and the redoxable label. The resulting change in electron transfer efficiency is readily measured by cyclic voltammetry at target DNA concentrations as…

• NS
  National Science Foundation

  Award: 0099843
• NI
  National Institutes of Health
• OO
  Office of Naval Research
• DO
  Division of Materials Research