Electrical transport through 60 base pairs of poly(dG)-poly(dC) DNA molecules

We report electrical transport through 60 base pairs of poly(dG)-poly(dC) DNA molecules. The DNA solution is dropped on two metal electrodes with the gap of 20 nm. The current-voltage characteristics measured between the electrodes exhibits clear staircases, which are reproducible over repeated measurements. The size of the observed staircases is consistent with the energy gap obtained from a tight binding calculation. (C) 2002 American Institute of Physics.