To Quench or Not: Extending a β-Carboline Fluorophore for TNT Detection in Aqueous Media via Simultaneous ESPT Destabilization and AIE.

Molecules relying on the excited-state intramolecular proton transfer/excited-state proton transfer (ESIPT/ESPT) mechanism are widely used in material science. In the current work, a known β-carboline-based probe TrySy was used to selectively detect explosive trinitrotoluene (TNT) in water. Compared to conventional TNT sensing, which relies mainly on the quenching of the fluorescence signal, TrySy could perform nanomolar detection of TNT via ESPT destabilization and AIE, with a significant fluorescence output. The mechanism followed was validated by computational and experimental results.