Highly sensitive and selective determination of Hg²⁺ by using 3-((2-(1H-benzo[<i>d</i>]imidazol-2-yl)phenylimino)methyl)benzene-1,2-diol as fluorescent chemosensor and its application in real water sample

<div><p>A new receptor 3-((2-(1H-benzo[<i>d</i>]imidazol-2-yl)phenylimino)methyl)benzene-1,2-diol (<b>1</b>) was synthesised and developed as a highly selective fluorescent chemosensor for the detection of Hg²⁺ in semi-aqueous media. The fluorescence of receptor <b>1</b> was dramatically and selectively quenched on complexation with Hg²⁺ ion with the detection limit down to 0.20 μM. The developed sensor was successfully applied for the determination of Hg²⁺ content in water samples. Density Functional Theory (DFT) calculations were performed to study the mechanistic behaviour behind the binding of Hg²⁺ with receptor <b>1</b>.</p>