Figure 3.

(A) Electron transfer derived from the redox activity of TH. Electron transfer produces a tunneling current when the probes are not hybridized to targets. When the hairpin is opened by heating, the tunneling current will be greatly weakened. However, when probes are coupled with targets, the electrons transfer along the double-stranded DNA as along a wire. (B) Comparison of experiments (circle) and simulation (square) for the redox current on the electrode in the process of hairpin loop unzipping.