Molecular Electronic Devices to Detect E. Coli

Detecting the presence of E. coli and other pathogenic bacteria is time consuming and expensive, requiring biological cell cultures or DNA amplification.

Researchers at the University of California, Davis, University of Washington, and TOBB University of Economics and Technology in Turkey have used a single-molecule break junction, a molecular electronic device, to detect RNA from different pathogenic strains of E. coli. 

“The reliable, efficient and inexpensive detection and identification of specific strains of microorganisms such as E. coli is a grand challenge in biology and the health sciences,” said Josh Hihath, an associate professor at University of California, Davis. “Our technique could pave the way for rapid, straightforward detection of pathogens, antimicrobial resistant bacterial strains and biomarkers for cancer.”

Single-molecule break junction devices have metal electrodes with sharp interfaces that interact with other molecules, such as RNA. When in the presence of target molecules, the distance between the electrodes changes, creating slight changes in the electrical current that is passed through the solution. The changes are so slight that hundreds of tests have to be done repeatedly, but the tests are super quick and therefore much faster than current technologies.

“One of the questions we asked is how small of a change in the sequence is needed to cause a meaningful change in the electrical conductance?” said Hihath. “The smallest thing we can change is a single-base, so we decided to see if a single-base change can be measured.”

The technology works with small strings of genetic molecules and should be translatable into a device that will be able to accept samples to test directly.

Study in Nature Nanotechnology: Detection and identification of genetic material via single-molecule conductance…

Via: University of California, Davis…