Two high school students of UC Santa Barbara and Nobel Laureate Alan Heeger created a real-time sensor for detecting cocaine by using inexpensive off-the-shelf electronics whose potential applications are far-reaching, including bioterrorism detection and important medical uses.

Co-author and Nobel laureate Alan Heeger said, "We have developed a method of detecting small molecules and proteins in a way that is not specific to cocaine -- a whole class of biosensors can be based on this concept. It can be applied to the prevention of bioterrorism. It is beautiful work; the sensor is fully portable."

To create the sensor, the researchers took a DNA molecule that converts from a floppy and unfolded shape into a structured, folded shape in the presence of cocaine. They then observe the change in the DNA by monitoring how electrons travel through it. There are DNA molecules available that bind to many different targets, so it follows that similar sensors can be easily made for other targets.

At present, the new sensor detects cocaine in the blood or saliva to a degree of a few micromolars, a concentration that would be the equivalent of detecting three parts per million in blood. Still researchers believe that more work needs to be done to increase the sensitivity of the new test.

More details from the UC Santa Barbara press release.