Have you ever been tempted to order steak tartare but decided against it for fear of getting sick? This little cell phone scanner can take a look at it for you and let you know if it does in fact harbor any E. coli bacteria.
It attaches to a typical cell phone camera and uses fluorescence imaging to detect the bacteria. Engineers at UCLA combined quantum dots, a type of tiny semiconductor, with capillaries containing antibodies. When the capillaries contain an E. coli sample, they emit light.