Pyrazoline-Based Fluorescent Probe: Synthesis, Characterization, Theoretical Simulation, and Detection of Picric Acid

Abstract

2-Pyrazoline containing benzothiazole ring 2-[1-(1,3-benzothiazol-2-yl)-5-(4methoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl]phenol (BP) have been synthesized for the effective identification of picric acid over other competing nitro compounds using fluorescence technique. The as-prepared pyrazoline BP showed quenching efficiency as high as 82% comparative to other nitro aromatics and the limit of detection was found to be 1.1 μM. The possible mechanism with the quenched AP detection efficiency was based on fluorescence energy transfer and photoinduced electron transfer. Moreover, the observed results were supported by the optimized structures of the compounds using the DFT/B3LYP/6-311G/LanL2DZ method. Eventually, the pyrazoline derivative BP was further utilized for real water samples, showing recoveries in the 87-101.06% and RSD was less than 3%.