Sensitive and Selective Detection of Tartrazine Based on TiO₂-Electrochemically Reduced Graphene Oxide Composite-Modified Electrodes

TiO₂-reduced graphene oxide composite-modified glassy carbon electrodes (TiO₂⁻ErGO⁻GCE) for the sensitive detection of tartrazine were prepared by drop casting followed by electrochemical reduction. The as-prepared material was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Cyclic voltammetry and second-order derivative linear scan voltammetry were performed to analyze the electrochemical sensing of tartrazine on different electrodes. The determination conditions (including pH, accumulation potential, and accumulation time) were optimized systematically. The results showed that the TiO₂⁻ErGO composites increased the electrochemical active area of the electrode and enhanced the electrochemical responses to tartrazine significantly. Under the optimum detection conditions, the peak current was found to be linear for tartrazine concentrations in the range of 2.0 × 10 ⁻2.0 × 10 mol/L, with a lower detection limit of 8.0 × 10 mol/L (S/N = 3). Finally, the proposed TiO₂⁻ErGO⁻GCEs were successfully applied for the detection of trace tartrazine in carbonated beverage samples.