A Sensitive Fluorescence Probe for the Trace Detection of Fe(III) Based on a Post‐Synthesis‐Modified Copper‐Based Metal‐Organic Framework

Abstract This work presents the generation of a post‐synthetically modified Metal‐Organic Framework (MOF), denoted as Cu‐BDC‐NH 2 ‐DHB, achieved through a Schiff‐base reaction by converting the pendant amino group in pristine Cu‐BDC‐NH 2 MOF to an imine group using 3,4‐dihydroxybenzaldehyde (DHB). The resulting material exhibited exceptional luminescence and fluorescence stability in water, prompting investigation into its potential as a metal sensor. Fluorescence tests revealed that Cu‐BDC‐NH 2 ‐DHB could be transformed into a highly selective and sensitive sensor for detecting Fe 3+ ions amid co‐interfering metal ions, with a remarkable detection limit of 3.08 μM. Furthermore, the results demonstrated that Fe 3+ induced a rapid and strong quenching effect, with a reaction time measured in seconds. This research provides a promising technique for the facile and immediate detection of Fe 3+ ions in practical applications.