Dogs have been used for decades to sniff out explosives, but now Otto J. Gregory ’75, M.S. ’77, professor of chemical engineering and co-director of URI’s Sensors and Surface Technology Partnership, has developed a sensor that can detect explosives commonly used by terrorists.

One of these explosives—triacetone triperoxide, or TATP—is used by terrorists worldwide, from the 2001 “shoe bomber” Richard Reid to the suicide bombers who attacked Paris last November. The explosive is relatively easy to make with chemicals that can be bought at pharmacies and hardware stores.

Gregory’s work focuses on creating a sensor that continuously detects vapors emitted by the explosive. What makes his research so significant is that his sensor could be used round-the-clock in public places like airports, subways, and ports of entry for cargo containers.

“If someone carrying TATP were to walk by in a relatively confined space, the sensor could detect it,’’ he says. The sensor can also determine if ammonium nitrate, TNT and other explosives are present.

Dogs can still be trained to track down explosives at very low levels, but sensors are a better long-term solution, Gregory says. “Dogs need to rest,” he points out. “Our sensors sniff continuously.