An Electrochemical Senor for Determination of Amlodipine Besylate Based on Graphene–Chitosan nanoComposite Film Modified Glassy Carbon Electrode and Application in biological and pharmaceutical sample

The graphene–chitosan composite film modified glassy carbon electrode was fabricated and used to determine amlodipine besylate. In 0.1 M pH 7.3 phosphate buffer solutions, the redox peak currents of amlodipine besylate increased significantly at graphene–chitosan composite film modified glassy carbon electrode compared with bare electrode and chitosan modified glassy carbon electrode, indicating that graphene possessed electrocatalytic activity towards amlodipine. The experimental conditions were optimized and the oxidation mechanism was discussed. Under the optimal experimental conditions, the oxidation peak current was proportional to amlodipine concentration in the range from to 1-70 µM with the correlation coefficient of 0.9930. The detection limit was 0.6 µM (S/N=3). Using the proposed method, amlodipine was successfully determined in serum sample, tablets and urine, suggesting that this method can be applied to determine amlodipine in pharmaceuticals.