Post-synthesis of curcumin-embedded zeolitic imidazole framework for copper ions detection

In this study, the amine-functionalized ZIF-11 material was fabricated through post-synthesis modification by using 2-aminobenzimidazole (ABI) to introduce ligand for detection of copper ions, enhancing the stability of ZIF-11 in aqueous solution, and generation an aggregation-fluorescent nanomaterials. A comprehensive set of characterization techniques, including Powder X-ray diffraction, N₂ sorption isotherms, scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermal gravimetric analysis, was employed to elucidate the properties of the amine-functionalized ZIF-11 and CUR loaded nanocomposites. This modification partially replaced the benzimidazole linkers in the ZIF-11-ABI structure with ABI linkers, enhancing the stability of the ZIF-11 in water. The fluorescence properties of curcumin in ZIF-11-ABI and ZIF-11 exhibited differences in copper ion capture sites. The observed fluorescence quenching of ZIF-11-ABI when immersed in a copper solution indicated the disruption of dimerization between zinc clusters and curcumin, caused by copper ions interacting with enol groups. These findings suggest that curcumin incorporated into ZIF-11-ABI has excellent potential as a marker material for the detection of copper ions.