A Voltammetric Sensor Based on Carbon Veil Modified with Graphene and Phytosynthesized Cobalt Oxide Nanoparticles for the Determination of Food Dyes Tartrazine (E102) and Allura Red (E129)

Abstract

A voltammetric sensor based on carbon veil modified with graphene nanoplates and phytosynthesized cobalt oxide Co3O4 nanoparticles is proposed for the determination of tartrazine (E102) and allura red AC (E129). The use of a composite nanomodifier contributes to an increase and better separation of the oxidation currents of azo dyes on their simultaneous presence. The process of the oxidation of azo dyes is irreversible, involves two electrons, and has a mixed nature. The sensor is characterized by a low limit of detection: 30 nM for E102 and 27 nM for E129, and in the inversion mode 16 and 3 nM, respectively. The analytical range the dyes is 0.1–15 µM. The sensor has been successfully used in the analysis of fruit jellies and beverage. The advantages of the developed sensor are high performance and operational characteristics, ease of manufacture, and low cost.