Here, we report a novel zinc-based metal-organic framework (Zn-MOF), synthesized via a solvothermal approach, as a highly selective and cost-effective fluorescent probe for detecting metronidazole, a widely used antibiotic linked to environmental and health risks. The MOF’s structural and optical properties, studied through spectroscopic and microscopic analyses, reveal tunable luminescence behavior that is selectively quenched in the presence of metronidazole. This fluorescence quenching mechanism enables precise detection of metronidazole across a broad linear range (10–346 µM) with a low detection limit of 0.25 µM. Also, the sensor demonstrates exceptional specificity for metronidazole even in complex biological matrices such as human serum, showing negligible interference from structurally analogous antibiotics and common ions. Its rapid response time, stability under diverse environmental conditions, and scalable fabrication process underscore its practicality for real-world applications. By addressing key limitations of existing techniques, including high cost, complexity, and cross-reactivity, this work establishes an applicable platform for monitoring antibiotic residues in clinical and environmental settings, advancing both material science and public health initiatives.
