Document Type : Original Article
Department of Analytical Chemistry, Faculty of Chemistry, VNU University of Science, Hanoi, Vietnam
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.