Unique carbazole – N,N-dimethylanline linked chalcone a colorimetric and fluorescent probe for picric acid explosive and its test strip analysis

Abstract

A unique carbazole-N,N-dimethylbenzamine chalcone probe was designed for a selective, sensitive fluorescent detection of threatening explosive Picric acid. The fluorescence of the novel ligand (E)-3-(4-(dimethylamino)phenyl)-1-(9-ethyl-9H-carbazol-6-yl)prop-2-en-1-one (CCNDA) quenches at 541 nm selectively with picric acid in pool of different nitroaromatic compounds (NACs). The sensor emits a green fluorescence which gradually quenches on addition of increasing concentration of picric acid to a pale yellow solution. The fluorescence quenching is attributed to the involvement of Intramolecular Charge Transfer through electrostatic and H-bonding interaction with picric acid. A lowest recognition limit of about 7.84 × 10−8 M was achieved using our sensor CCNDA. The three dimensional emission spectral behavior of the ligand CCNDA in presence of picric acid was also studied. Test strip experiment was done to find the practical applicability of the sensor.