Design of Solid‐contact Ion‐selective Electrode with Graphene Transducer Layer for the Determination of Flavoxate Hydrochloride in Dosage Form and in Spiked Human Plasma

Eco‐friendly solid‐contact ion selective electrode was fabricated and optimized for the determination of flavoxate hydrochloride in presence of its main metabolite. The process is based on carbon screen printed electrode and polyvinyl chloride polymeric sensing membrane. The first optimization step involved the ionophore selection through screening various ionophores, where calix[4]arene showed the highest affinity towards flavoxate. The second step, a graphene nanocomposite interlayer was employed as the ion‐to‐electron transducer between the carbon electrode and the polymeric ion sensing membrane. The graphene layer decreased the potential drift down to