Label free electrochemical detection of nucleic acid on a disposable electrode

A label free electrochemical technology for rapid quantification of DNA is presented. This technology, if successful, would make it simple and practical to perform genetic identifications in the field, for example to diagnose plant diseases. Our observations indicate that the detection limit for this technology may be significantly lower than 1OpM. Using this technology, DNA could be reliably quantified over a wide dynamic range from 100 nM down to below 10 pM. Hybridization reactions could be detected within 10 minutes of contact with the probe. Specificity was not observed in the system, however. In fact the probes were more sensitive to non-target sequences than sequences to which the probe was designed. This problem may have occurred due to unintended complementarity of the non-target DNA to the stem region of the probe, suggesting that the stem is extremely sensitive to competition from complementary sequences. This possibility may be used in the future to design more sensitive and selective probes.