Method and apparatus for sequencing polymers through tunneling conductance variation detection

A system for sequencing molecules of a polymer, comprising:

• a pair of nano-electrodes arranged to sequentially receive linked molecules of a polymer in solution in a channel formed therebetween;
• a signal generator electrically connected to the nano-electrodes an configured to center a fixed bias voltage across the nano-electrodes corresponding to the energy difference between any two internal energy levels of a molecule of interest and to modulate the bias voltage with a modulation waveform;
• means for urging the polymer through the channel;
• means for measuring tunneling current between the nano-electrodes while a molecule portion of the polymer passes through the channel;
• and
• signal processor for deriving an electrical signal indicative of the molecule of interest from the tunneling current and identifying the molecule of interest by comparing the derived electrical signal to known values of the electrical signal for the molecule of interest.