Electrochemical study of allura red at glassy carbon electrode modified with the reduced graphene oxide and its determination in food by adsorptive stripping voltammetry

The electrochemical properties of Allura red on a glassy carbon electrode modified with the electrochemically reduced graphene oxide (ErGO/GCE) was investigated by cyclic voltammetry and differential pulse adsorptive anodic stripping voltammetry. The ErGO/GCE was fabricated of electrochemical reduced method in conditions: Graphene oxide was dispersed in water and electrochemically reduced for 15 cycles, potential scan range from 0 V to -1.5 V, scan rate 30 mV.s-1. The electrochemical behaviors of Allura red on the ErGO/GCE are semi-reversible oxidation and the Allura red had adsorptive on the surface of ErGO/GCE. The optimal conditions for determination of Allura red were Britton-Robinson buffer pH = 2.5, adsorption potential 0.5 V, adsorption time 15 s, and scanning rate 12.5 mV.s-1, linearity range from 10-7 mol.L-1 to 8×10-7 mol.L-1. The limit of detection (LOD) is 2.8×10-8 mol.L-1 and limit of quantification is 9.3×10-8 mol.L-1. The ErGO/GCE was successfully used in the determination of Allura red content in food samples with high sensitivity and accuracy, simple and low cost.