A Fast-Response ZnII Metal–Organic Framework Sensor toward Nitrofurazone Antibiotics and Anthrax Biomarkers in Living Cells

The rapid and accurate detection of antibiotics and disease biomarkers is crucial for disease prevention, diagnosis, and treatment. Herein, a novel multidentate ligand containing a benzothiadiazole unit, namely, 4,7-bis(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole (BIBT), together with 4,4′-stilbenedicaroxylic acid (H2SBCA), was employed to synthesize a new three-dimensional seven-fold interpenetrating stable ZnII metal–organic framework (MOF) under solvothermal conditions, with the chemical formula {[Zn4(BIBT)4(SBCA)4]·DMF}n (JXUST-67, where JXUST refers to Jiangxi University of Science and Technology; DMF = N,N-dimethylformamide). After immersion in aqueous solutions at pH 2–12 for 24 h, JXUST-67 remained structurally intact. Fluorescence sensing experiments demonstrate that JXUST-67 can serve as a fast-response (≤10 s) turn-off sensor for nitrofurazone (NFZ) and a turn-on sensor for 2,6-pyridinedicarboxylic acid (DPA) and both analytes can be recognized by the naked eye, achieving detection limits of 0.1378 and 0.0048 μM, respectively. Furthermore, cycling tests show that JXUST-67 is a reusable sensor material. More importantly, JXUST-67 exhibits good biocompatibility and low cytotoxicity toward living cells and successfully detects DPA in live cells, demonstrating significant potential for biosensing applications.