An electrochemical sensor for amaranth and ponceau 4R determination based on gold electrode modified with silver-reduced graphene oxide

Ponceau 4R and amaranth are synthetic azo dyes commonly used in the food and beverage industry. However, excessive consumption of these dyes can pose potential health risks. This study describes a novel electrochemical sensor based on an electrochemical-reduced graphene oxide and silver (Ag-ErGO) modified gold electrode for the simultaneous determination of ponceau 4R and amaranth in soft drinks. The sensor was fabricated by electrochemically reducing graphene oxide and silver ion on a gold electrode (AuE). The morphology, structure, and composition of Ag-ErGO and graphene oxide on the gold electrode surface were characterized using SEM, IR spectroscopy, and EDS analysis. Adsorptive stripping voltammetry (AdSV) combined with cyclic voltammetry (CV) was employed to investigate the electrochemical behavior of ponceau 4R and amaranth. The optimal conditions were chosen to be Britton-Robinson buffer pH 2.0, adsorption potential 0.5 V, adsorption time 60 s, and scan rate 12.5 mV/s. The linearity ranges were from 0.0302 to 0.2418 mg·L⁻¹ and 0.0604 to 0.4836 mg·L⁻¹ with the detection limits 0.0074 mg·L⁻¹ and 0.0188 mg·L⁻¹ for simultaneously determination of ponceau 4R and amaranth, respectively. The proposed method was successfully applied to determine ponceau 4R and amaranth in soft drink samples.