TNT is both toxic and explosive, and therefore, the detection of TNT represents an environmental concern and a security concern. Dogs are often used for detection, but other methods are needed. This laboratory investigates a ruthenium bipyridine ([Ru(bpy)[subscript 3]][superscript 2+]) luminescence-based trinitrotoluene (TNT) sensor. Students will synthesize [Ru(bpy)[subscript 3]][superscript 2+], investigate sensors, and consider possible mechanistic pathways of quenching. Students are unlikely to have analyzed luminescence quenching data previously, and using TNT shows how important the technique is for problems like national security, environmental contamination, and land mine deactivation. The content of the lab is ideal for upper-level laboratories, when students have the foundational coursework to appreciate the interdisciplinary nature of chemistry as the experiment integrates inorganic, analytical, and physical chemistry.