Development of stripping voltammetry using glassy carbon electrode modified with electrochemical reduced graphene oxide for the determination of amaranth in soft drink and candy samples

Abstract

In this study, the manufacturing conditions of glassy carbon electrode modified with electrochemical reduced graphene oxide (ErGO/GCE) were elucidated to determine amaranth in soft drink and candy samples by adsorptive stripping voltammatry. The ErGO/GCE was fabricated through an electrochemical reduction process of graphene oxide in the potential range from 0 V to −1.5 V using cyclic voltammetry method. Characteristics of graphene oxide and reduced graphene oxide were studied by FT-IR, XRD, TEM, SEM. Amaranth is adsorbed on the ErGO/GCE working electrode surface through an irreversible oxidation process. The optimal conditions used to determine amaranth are Britton-Robinson buffer solution of pH 3.0, an adsorption potential at 0 V, an adsorption time of 30 s, at a scan rate of 20 mV/s, a linearity range from 1.0 × 10−7 mol. L−1 to 1.0 × 10−6 mol. L−1, a (LOD) detection limit of 2.8 × 10−8 mol. L−1 and a (LOQ) qualification limit of 9.3 × 10−8 mol. L−1. The proposed method can be applied to determine amaranth dye in food.