The present invention provides methods and devices for detecting a target nucleic acid molecule. A set of oligonucleotide probes integrated into an electric circuit, where the oligonucleotide probes are positioned such that they can not come into contact with one another, are contacted with a sample. If the sample contains a target nucleic acid molecule, one which has sequences complimentary to both probes, the target nucleic acid molecule can bridge the gap between the probes. The resulting bridge can then carry electrical current between the two probes, indicating the presence of the target nucleic acid molecule.