A highly sensitive electrochemical sensor for simultaneous detection of uric acid, xanthine and hypoxanthine based on poly(l-methionine) modified glassy carbon electrode

A poly l-methionine modified GC electrode was fabricated by electrochemical polymerization of the l-methionine on a glassy carbon electrode. The electrochemical behaviors of uric acid, xanthine and hypoxanthine at the modified electrode were studied by cyclic voltammetry and differential pulse voltammetry. The results showed that this modified electrode exhibited excellent electrocatalytic activity toward the oxidation of the uric acid, xanthine and hypoxanthine. Also, electrode was used for simultaneous determination of uric acid, xanthine and hypoxanthine. This modified electrode possesses high sensitivity, and the detection limits as values 0.007, 0.004 and 0.008 μM for uric acid, xanthine and hypoxanthine, respectively. Finally, the poly l-methionine modified electrode was successfully employed to detect uric acid, xanthine and hypoxanthine in the serum samples with good selectivity and high sensitivity.