By spraying surfaces with a light-emitting polymer, researchers have taken a step toward making new sensors for traces of common explosives. Such detectors may even prove useful for finding bombs and mines under water.
To make the sensitive coating, a team of scientists at the University of California, San Diego modified polytetraphenyl-1,1 silole. This polymer consists of single-atom-thick silicon filaments in a jacket of organic molecules that the researchers refer to as "chicken fat."
Ordinarily, the polymer glows green under ultraviolet radiation. That's because the radiation energizes electrons in the silicon, which then emit green light as they naturally fall back to a lower energy state.