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-NH2-DHB, achieved through a Schiff-base reaction by converting the pendant amino group in pristine Cu-BDC-NH2 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-NH2-DHB could be transformed into a highly selective and sensitive sensor for detecting Fe3+ ions amid co-interfering metal ions, with a remarkable detection limit of 3.08 μM. Furthermore, the results demonstrated that Fe3+ 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 Fe3+ ions in practical applications.