Benjamin Miller, professor of Biomedical Engineering at the University, and Philippe Fauchet, professor of Electrical and Computer Engineering, have devised a sand-grain sized wafer that can differentiate between two classes of bacteria, called Gram-positive and Gram-negative.

The sensor, the first substantial improvement in identifying Gram-positive and negative bacteria since Hans Christian Joachim Gram developed the original staining technique in 1884, is reported in the upcoming issue of the Journal of the American Chemical Society. The accomplishment is evidence that it's indeed possible to accurately identify bacteria with a silicon sensor, spurring Miller's team to expand the research to several other types of bacteria, including salmonella, listeria and enteropathogenic E. coli, all of which can cause serious disease in humans.