A pyrene-based covalent organic framework fluorescence sensor with dual response for highly sensitive detection of Cu2+ and Fe3+

In this study, we developed a fluorescent sensor based on a pyrene-derived covalent organic framework (PT 2 D-COFs) for the efficient and sensitive detection of copper ions (Cu 2+ ) and iron ions (Fe 3+ ). The PT 2 D-COFs are synthesized via a Schiff base reaction, exhibiting high crystallinity, excellent porosity, and remarkable chemical stability, which provide ideal coordination sites for the effective recognition of metal ions. The results demonstrate that the PT 2 D-COFs exhibit significant fluorescence quenching upon interaction with Cu 2 ⁺, with a detection limit (LOD) of 0.79 nM, while fluorescence enhancement is observed in the presence of Fe 3+ , with an LOD of 0.47 nM. and reproducibility in complex sample matrices. It was effectively utilized to quantify Cu 2+ and Fe 3+ in environmental water samples and traditional Chinese herbal medicines, achieving satisfactory recovery rates. This sensor demonstrates characterized by its low detection limits, strong anti-interference capability, and broad application potential, holds significant promise for applications in environmental monitoring and bioanalysis. Graphical abstract