Development of a Cobalt Tetra (diethoxycarbonylmethyl) phthalocyanine‐Based Benzydamine‐Selective Poly Vinyl Chloride Membrane Potentiometric Sensor

Benzydamine (BNZ) overdose can lead to serious adverse effects, including hallucinations, urticaria, bronchospasm, and renal dysfunction. Therefore, its selective and sensitive determination is essential. In this study, a novel potentiometric sensor for BNZ was developed using cobalt tetra(diethoxycarbonylmethyl)phthalocyanine (CoPc) as the ionophore. The surface morphology of the sensor was confirmed by scanning electron microscopy (SEM). The developed sensor exhibited a Nernst slope of 59.6 mV/decade in the concentration range of 1.0 × 10 −8 −1.0 × 10 −2 M, a detection limit of 9.5 × 10 −9 M, a fast response time of 10 s, and stable performance in the pH range of 2.10–8.00. It demonstrated a 34‐day operational lifetime and high selectivity, with stability further confirmed by water layer tests and potential drift measurements. Successful application in pharmaceutical formulations and physiological serum samples validated its practical utility. Compared to previously reported potentiometric sensors, this sensor offers a wider linear range and lower detection limit, providing a rapid, selective, and reliable tool for BNZ determination.