A chemical sensor prototype will be able to detect “single-fingerprint quantities” of substances from a distance of more than 100 feet away, and its developers are working to shrink it to the size of a shoebox. It could potentially be used to identify traces of drugs and explosives, as well as speeding the analysis of certain medical samples. A portable infrared chemical sensor could be mounted on a drone or carried by users such as doctors, police, border officials and soldiers.