Aggregates of a hydrazono-sulfonamide adduct as picric acid sensors†
A novel hydrazono-sulfonamide adduct (AVM) was designed and synthesized. Due to the inhibition of CN isomerization with a higher water content, the adduct shows remarkable aggregation induced emission enhancement (AIEE) properties in a THF : water solvent system. The formation of nanoaggregates was confirmed by transmission electron microscopy (TEM) analysis. Theoretical DFT calculations supported the observed photophysical changes. These aggregates of AVM act as selective and sensitive sensors for picric acid via a fluorescence quenching mechanism. The efficiency of the quenching process was calculated using the Stern–Volmer equation. The detection limit was found to be 80 nM. In addition, contact mode detection using fluorescent test strips was developed to demonstrate the solid phase sensing of picric acid.