Voltammetric Determination of Epinephrine and Uric Acid using Modified Graphene Oxide Nano Sheets Paste Electrode

Resumo

A carbon paste electrode was prepared and modified with 3-(4'-amino-3'-hydroxy-biphenyl-4-yl)-acrylic acid and graphene nanosheets. In phosphate buffer solution, the modified electrode showed an excellent electrocatalytic effect on the oxidation of epinephrine. This was further used to determine epinephrine in the presence of uric acid by square wave voltammetry. The oxidation peak current showed a linear relationship with the concentration of epinephrine in the range of 1.0 × 10^–7 to 5.0 × 10^–5 M, with the detection limit of 5 × 10^–8 M. The method has high sensitivity, selectivity, stability, and has been successfully applied to determining epinephrine and uric acid in real samples.