Pheromonic sensor

The pheromonic sensor was a type of sensor commonly used on explosive devices. They were triggered when a particular individual or species came within range. Flaxian assassins were known to favor pheromonic sensors, so Elim Garak used a pheromonic sensor to trigger a bomb in his shop in 2371, thus implicating the Flaxian assassin Retaya. 

Ferengi locator bombs use pheromonic sensors to lock onto their target.