Highly selective and sensitive ‘on–off’ fluorescent chemosensor for Fe³⁺ ions crafted by benzofuran moiety in both experimental and theoretical methods

A benzofuran glycinamide‐based chemosensor, 3‐(2‐([4‐fluorobenzyl]amino)acetamido)benzofuran‐2‐carboxamide ( BGA ) was developed and synthesized for the selective and sensitive detection of Fe 3+ ions. The photophysical properties of the probe BGA were studied using UV–visible light absorption and fluorescence spectrophotometers. The chemosensor BGA showed a marked ‘on–off’ fluorescence response towards Fe 3+ ions in the presence of other metal ions in DMSO/H 2 O solution (9/1, v/v). The very low limits of detection (LOD) were calculated to be 10 nM and 43 nM using UV–visible light absorption and fluorescence spectrophotometers, respectively. Job's plot analysis revealed the formation of a BGA ‐Fe 3+ complex with a 1:1 binding stoichiometry ratio using UV–visible light spectroscopy. The sensing mechanism was also demonstrated using density functional theory calculation.