Carbon dot-decorated metal-organic framework composite for Fe3+ detection in the aqueous environment

The contamination of heavy metal ions in the aqueous environment constitutes an important threat to human survival. Hence, the development of simple, effective, and cheap detection of heavy metals and pesticide residues is essential for environmental control. Here, we synthesized a yellow carbon dots-linked ZIF-8 (yCDs/ZIF-8) composite, which was prepared with excellent photoluminescence properties and aqueous stability, and characterized by strong yellow fluorescence emission. The ratio metric fluorescence sensor has been constructed using its stable light blue carbon dots. The fluorescence sensor has excellent selectivity and sensitivity as a sensing probe for Fe3+ ions, with a detection limit of 0.3690 μM. In addition, the fluorescence quench mechanism was investigated. It has been shown that the yCDs/ZIF-8 fluorescence could be quenched by Fe3+ via static quenching and absorption competition mechanisms. The probe has high-quality application potential in terms of food safety and environmental monitoring due to the fact of its simplicity, high yield, and low cost.