Development of a silver screen-printed paper card modified with gold nanoparticles decorated nitrogen doped graphene electrode for voltammetric determination of tenofovir

Abstract

A new method for detecting tenofovir has been developed using a silver screen-printed paper card and voltammetric techniques. Gold nanoparticles (AuNPs) were deposited onto nitrogen-doped graphene (NG) using a simple reduction method, resulting in a gold nanoparticles-decorated nitrogen-doped graphene (AuNPs-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). The response obtained with the modified electrode showed 1.6 times higher sensitivity compared to the unmodified electrode, achieving linear calibration from 20 to 100 µM 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. The limit of detection (LOD) of 16 µM was obtained with a limit of quantification (LOQ) of 56.6 µM.