An Electrochemical Senor for Determination of Sulfamethazine Based on C3N4–Chitosan NanoComposite Film Modified Glassy Carbon Electrode and Application in Biological and Pharmaceutical Samples

The C3N4–chitosan composite film modified glassy carbon electrode was fabricated and used to determine sulfamethazine. In pH 5.3 phosphate buffer solutions, the redox peak currents of sulfamethazine increased significantly at C3N4– chitosan composite film modified glassy carbon electrode compared with bare electrode and chitosan modified glassy carbon electrode, indicating that C3N4 possessed electrocatalytic activity towards sulfamethazine. The experimental conditions were optimized and the oxidation mechanism was discussed. Under the optimal experimental conditions, the oxidation peak current was proportional to sulfamethazine concentration in the range from to 0.8-54 μM with the correlation coefficient of 0.9930. The detection limit was 0.4 μM (S/N=3). Using the proposed method, sulfamethazine was successfully determined in serum sample, tablets and urine, suggesting that this method can be applied to determine sulfamethazine in pharmaceuticals.