Development of a Silver Screen-Printed Paper Card Modified Gold Nitrogen Doped Graphene Electrode for Voltammetric Determination of Tenofovir

A new method for detecting tenofovir has been developed using a silver screen-printed paper card and voltammetric techniques. Gold nanoparticles (Au) were deposited onto nitrogen-doped graphene (NG) using a simple reduction method, resulting in a gold-decorated nitrogen-doped graphene (Au-NG) composite. The paper card was screen printed with silver ink, after which the composite was used to modify the paper card-based silver electrode and applied in the voltammetric detection of tenofovir. The sensor's characteristics were analysed using transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). Electrochemical studies were performed using cyclic voltammetry (CV) and Differential pulse voltammetry (DPV). DPV with the modified electrode demonstrated a sensitivity 1.6 times higher than that of the unmodified electrode, achieving a linear calibration at a scan rate of 100 mV/s and pH 8 in acetate buffer. The sensor displayed strong resistance to interference from other ions and was successfully tested on real samples.