Selective and Sensitive Detection of 2,4,6 Trinitrophenol (TNP) by Imidazolium Salt in Aqueous Medium

Abstract The synthesis and spectral characteristics of a fluorescent probe AQIm for 2,4,6 trinitrophenol (TNP) detection are reported in this study. The probe exhibited good sensitivity, selectivity, and efficiency for TNP detection in aqueous medium. The sensing mechanism was confirmed through UV–visible absorption, fluorescence, and 1 H NMR spectroscopy studies. Job's plot, cyclic voltammetry, theoretical calculations, and lifetime measurements suggested that the ground state charge transfer complex formation and inner filter effect (IFE) mechanisms might be the reasons for the fluorescence quenching. AQImM exhibited remarkable sensitivity and selectivity towards TNP with a low detection limit of 4 × 10 −7 M and a high quenching constant ( K sv ) of 1.51 × 10 4 M −1 . The probe could efficiently detect TNP in natural water and soil samples.