Development of a potentiometric biosensor for the determination of the active ingredient desloratadine antihistamines

Desloratadine is a second-generation antihistamine, an H1 receptor blocker frequently used in the treatment of allergic reactions. In this thesis study, ionophore synthesis was performed using the desloratadine-tetraphenylborate ion pair to make the developed sensor selective for desloratadine. The synthesized DES-TPB ionophore was combined with polyvinyl chloride (PVC) and various plasticizers at different ratios to form the membrane surface. To ensure the sensor's selectivity for desloratadine, the membrane surfaces were coated with a solid contact material to prepare desloratadine-selective potentiometric sensors. The best potentiometric response from the prepared sensors was obtained from the sensor composed of a membrane composition containing 6.0% ionophore, 32.0% PVC, and 62.0% o-NPOE (ortho-nitrophenyl octyl ether) plasticizer by weight. Potentiometric measurements conducted with the developed sensor revealed a linear operating range with a slope of R²=0.9926 over the concentration range of 1.0×10⁻7–1.0×10⁻2 M. It was observed that the sensor operates unaffected by pH changes in the pH=6.0-10.0 range, with a response time of 6 seconds. The sensor demonstrated good performance characteristics in the temperature range of 15-35 0C. It was determined that the desloratadine selective sensor has a service life of 6 weeks. It was also found that the sensor provides reliable and accurate results in titration applications and real sample analysis. The sensor was found to be sensitive to desloratadine and showed good selectivity. The sensor was found to be stable and reliable in real sample analysis.