Construction of a novel sensor based on activated nanodiamonds, zinc oxide, and silver nanoparticles for the determination of a selective inhibitor of cyclic guanosine monophosphate in real biological and food samples

Abstract

In the present work, we developed a highly sensitive and selective method for the determination of sildenafil (SIL) using a modified glassy carbon electrode (GCE) with activated nanodiamonds, zinc oxide, and silver nanoparticles nanocomposite (AND@ZnO-Ag/GCE). Various voltammetric techniques, including CV, DPV, and EIS, were employed to investigate the electrochemical process of SIL on the modified electrode. The resulting AND@ZnO-Ag/GCE electrode exhibited enhanced electron transfer between the electrode and the analyte, resulting in an excellent electrocatalytic performance for SIL oxidation under optimized conditions. The analytical performance of the AND@ZnO-Ag/GCE sensor demonstrated two linear responses within the concentration range of 0.01–0.08 μM and 0.08–14.6 μM, with a remarkably low detection limit of 7.08 nM. Moreover, the modified sensor (AND@ZnO-Ag/GCE) exhibited high selectivity and anti-interference capacity. It successfully detected trace amounts of SIL in biological and food samples, yielding satisfactory results. Furthermore, this work provides insights into the potential adulteration of energy drinks with sildenafil, addressing an area that has received limited attention in previous research.