A phthalimide-functionalized UiO-66 metal-organic framework for the fluorogenic detection of hydrazine in live cells

Here, we demonstrated the synthesis, characterization and application of a phthalimide-functionalized UiO-66 metal-organic framework, which showed an intrinsic detection capability for hydrazine. The MOF material (1) was solvothermally prepared by the reaction between ZrCl₄ and 2-(1,3-dioxoisoindolin-2-yl)benzene-1,4-dioic acid (H₂L) ligand in DMF solvent in the presence of benzoic acid for 48 h at 120 °C. The guest molecule free material (1') was used as a turn-on fluorescent sensor for the selective detection of hydrazine under biological conditions. The phthalimide group anchored in the structure of 1' is converted to the amine group by reaction with hydrazine and this free amine is accountable for the turn-on fluorescence behavior. The probe exhibited an extraordinary detection limit towards hydrazine (0.87 μM). The cellular imaging ability of the MOF probe for hydrazine was also demonstrated with MDAMB-231 breast cancer cells. The probe-loaded cells didn't show considerable cellular cytotoxicity and morphological deformities. They responded towards hydrazine solution by giving an intense blue fluorescent signal. Hence, 1' is capable of monitoring hydrazine in both the aqueous phase and living cells.