Recognition Tunneling Measurement of the Conductance of DNA Bases Embedded in Self-Assembled Monolayers

The DNA bases interact strongly with gold electrodes, complicating efforts to measure the tunneling conductance through hydrogen-bonded Watson−Crick base pairs. When bases are embedded in a self-assembled alkanethiol monolayer to minimize these interactions, new features appear in the tunneling data. These new features track the predictions of density functional calculations quite well, suggesting that they reflect tunnel conductance through hydrogen-bonded base pairs.