Aggregation-Induced Emission Active Donor-Acceptor Fluorophore as a Dual Sensor for Volatile Acids and Aromatic Amines

In the present work, a novel donor (D)-acceptor (A) fluorophore based on indeno-pyrrole derivative (PYROMe) has been utilized as a dual sensor for volatile acids and aromatic amines, where sensory responses were regulated by aggregation-induced emission (AIE) property. The twisted structural framework of PYROMe, confirmed by crystal study, avoids closed cofacial encounter upon aggregation and aided with augmented rigidity via different noncovalent interactions that ultimately ensued restricted intramolecular rotation (RIR). Consequently, PYROMe exhibited AIE in THF/H2O mixture along with bright solid state emission. The accessibility of protonation at carbonyl site and feasible HOMO energy to accept electron from aromatic amines during photoexcitation enabled PYROMe as a potential dual sensor. A thin film of PYROMe was utilized for quantitative detection of volatile acids and aromatic amines and the detection limit (DL) was found to be as low as 0.77 ppm and 6.04 ppb for trifluoroacetic acid (TFA) and ani...