Sensitive voltammetric determination of rutin in pharmaceuticals, human serum, and traditional Chinese medicines using a glassy carbon electrode coated with graphene nanosheets, chitosan, and a poly(amido amine) dendrimer

The electrochemical behavior of rutin was investigated in pH 6.0 buffer solution using a glassy carbon electrode coated with graphene nanosheets, chitosan and a poly (amidoamine) dendrimer in pH 6.0 buffer solution. The results indicate that the modified electrode displays electrochemical redox activity towards rutin, and that the oxidation peak current of rutin increases significantly compared to that at other electrodes. The amount of immobilized graphene and dendrimer, pH value, scan rate, accumulation time and accumulation potential were optimized. The kinetic parameters, charge transfer coefficient, transfer electron number, proton transfer number, standard rate constant, were calculated. Under the optimized conditions, the oxidation peak current is proportional to the concentration of rutin in the range between 0.001 and 2.0 μmol L −1 ( R  = 0.9991). The detection limit is 0.6 nmol L −1 (at S/N  = 3). The electrode exhibits satisfactory selectivity and reproducibility and was applied to the determination of rutin in pharmaceutical preparations, spiked human serum, and traditional Chinese medicine, with recoveries between 97.2 and 104.67%. 1. Preparation of graphene nanosheets and PAMAM modified glassy carbon electrode. 2. Graphene nanosheets and PAMAM improve the electrochemical redox of rutin. 3. The prepared electrode determines rutine with high sensitivity and selectivity. 4. The developed method can determine rutin in pharmaceutical formulations, human serum, and traditional Chinese medicine.