Faculty Sponsor's Department(s):
Devices that can amplify and detect DNA in a matter of hours would prove invaluable for healthcare workers and law enforcement personnel, but currently no such system is available. Electrochemical DNA sensors could be the key component in such a handheld DNA testing gadget. The current generation of such sensors, however, uses a signal off architecture. In other words, the signal decreases upon detection of a specific DNA sequence. There are several problems with this method, for example, the signal can decrease due to degradation or chemical inference which could lead to a false positive test result. Furthermore, signal off sensors cannot have a signal loss of more than 100 percent. We have developed a new device in which bifurcated DNA is used as a signal on architecture. The new sensor has demonstrated more than 350% signal gain upon binding target sequences. This instrument could be used to quickly analyze PCR products as the sensor is capable of recognizing three basepair mismatches; this is not particularly specific, however, it leaves a margin of versatility when detecting mutant nucleic acids. At this stage of the project, our goal is to make the device behave more consistently by altering a variety of parameters in the sensor preparation procedure. Although the detection limit of the sensor remains around 1nM, which is inferior to previously developed sensors, it is more than adequate for detecting PCR product.