Design and application of supramolecular based solid-contact ion-selective electrode for selective green determination of tenofovir disoproxil fumarate

Abstract

This work describes the fabrication of solid-contact potentiometric sensor to determine the antiviral drug; tenofovir disoproxil fumarate. Screen-printed carbon electrodes have been selected as being a disposable substrate material. Ion sensing membrane is based on Polyvinyl chloride (PVC) polymer that was impregnated with calix [6] arene as being an ionophore for facilitating transferring the drug of interest from the sample phase into the membrane phase through decreasing Gibbs free energy of transfer. We applied a graphene nanocomposite interlayer between the carbon substrate and the polymeric membrane for overcoming potential drift, which is commonly encountered in solid-contact potentiometric sensors. As a result, the graphene nanocomposite layer enhanced the sensor performance and stabilized the potential signal as compared to the control sensor. The sensor performance characteristics were studied according to International Union of Pure and Applied Chemistry (IUPAC) recommendations, and linear range has been 0.01 M - 10 μM with limit of detection (LOD) 7.3 μM. We utilized the sensor for inline determination of the release of tenofovir disoproxil fumarate from its tablet pharmaceutical formulation without any separation or sample pre-treatment steps. In an attempt to be eco-friendly through evaluating the suggested method regarding its greenness, the method has been found to be excellent green according to the eco scale method.