An "ON-OFF" fluorescent sensor based on a novel zinc-based flower-like structured metal-organic framework for sequential detection of deferasirox and tigecycline

Deferasirox (DEF) is essential for patients with thalassemia requiring long-term transfusion therapy. Tigecycline (TIGE) is a first-line drug for the clinical treatment of complex, severe bacterial infections. The two drugs can be coordinated to treat Pseudomonas aeruginosa infections. Easy and efficient techniques for monitoring these two drugs in biological samples are few. Metal-organic framework (Zn-MOF) prepared from zinc nitrate hexahydrate and dithioglycolic acid has a flower structure. Interestingly, Zn-MOF can cause DEF to aggregate on it and induce DEF luminescence. The principle may be that Zn-MOF limits the vibration and rotation of DEF to avoid its nonradiative jump, which triggers aggregation-induced emission (AIE) and exhibits intense fluorescence. Further investigation revealed that TIGE could decompose Zn-MOF, thus alleviating the inhibitory effect of Zn-MOF on DEF and reducing the fluorescence intensity of DEF@Zn-MOF. A DEF/TIGE detection biosensor was created based on the fluorescence "turn-on" effect of Zn-MOF on DEF and the fluorescence "turn-off" effect of TIGE on DEF@Zn-MOF. The proposed technique was subsequently used to identify DEF/TIGE levels in pharmaceuticals and human plasma. The mean values for the percentage of the labeled amount of DEF/TIGE in DEF dispersible tablets/TIGE injection were 104.5 and 104.9%, respectively. The detection limits for the fluorescence detection of DEF and TIGE were 3.6 and 1.2 nM, respectively. This fluorescence assay is the first application of MOF to the simultaneous detection of DEF and TIGE and has the advantages of rapid sensitivity and high selectivity, providing a new strategy for drug detection.