Development of a MOF-Based Oxytetracycline-Selective PVC Membrane Potentiometric Sensor

Abstract

Oxytetracycline is widely used in veterinary medicine to protect animals from infections, treat existing conditions, and mitigate stress-related events such as vaccination, transportation, and medication. However, an overdose of oxytetracycline may lead to several adverse effects, including renal dysfunction, altered mental status, hepatotoxicity, and gastrointestinal disorders. Therefore, accurate determination of oxytetracycline is essential to ensure both therapeutic efficacy and patient safety. In this study, a polyvinyl chloride (PVC) membrane-based potentiometric sensor selective for oxytetracycline was developed using MIL-53 (Materials of Institut Lavoisier) as the ionophore. The optimal membrane composition consisted of 3% MIL-53, 64% nitrophenyloctylether (NPOE), 1% potassium tetrakis(4-chlorophenyl)borate (KTpClPB), and 32% PVC. The sensor exhibited a linear response in the concentration range of 1.0 × 10−2 to 1.0 × 10−⁷ M, with a Nernstian slope of 53.1 mV/decade. The pH working range was determined to be 4.56–11.00. It can be concluded that the developed solid contact potentiometric sensor offers satisfactory analytical properties. Analytical application of the sensor was successfully implemented in pharmaceutical formulations, physiological serum, and different water samples. © 2025 Wiley-VCH GmbH.