Fluorometric sensing of hydroxyl amine in aqueous medium utilizing a diphenyl imidazole-based probe

The detection of hydroxyl amine in aqueous medium is challenging due to its very similar chemical reactivity with nearer competitors such as hydrazine hydrate and primary amines. Moreover, the detection of hydroxyl amine at neutral pH adds further complexity to the sensing phenomenon due to its poor reactivity in neutral aqueous medium. In this work, we have presented a diphenyl imidazole benzaldehyde (DIB) probe which demonstrates the detection of hydroxylamine (HA) in micromolar concentration with high selectivity in 5% DMSO phosphate buffer solution at pH 7.4 via a fluorescence “turn-on” signal. The interaction of hydroxyl amine with the probe has been comprehensively studied by using fluorescence technique, proton NMR, FTIR, ESI-Mass and DLS measurements. The experimental results were further corroborated with the DFT studies. These results could pave the way toward the development of molecular indicators for hydroxyl amine in chemical and biological platforms.