Simultaneous Determination of Uric Acid and Xanthine Using a Poly(Methylene Blue) and Electrochemically Reduced Graphene Oxide Composite Film Modified Electrode

Figure 11

SWVs of different concentrations of UA (a) (from a to p: 0.08, 0.1, 0.5, 1, 2.5, 5, 7.5, 10, 25, 50, 75, 100, 200, 300, 400, 500 μM), Xa (b) (from a to p: 0.05, 0.08, 0.1, 0.5, 1, 2.5, 5, 7.5, 10, 25, 50, 75, 100, 200, 300, 400 μM), and the mixture solution of UA and Xa (c) (from a to o: 0.08, 0.1, 0.5, 1, 2.5, 5, 7.5, 10, 25, 50, 75, 100, 200, 300, 400 μM) with step for 5 mV, amplitude for 30 mV, frequency for 5 Hz, and quiet time for 2 min. Insets show the calibration plots of lgI-lgC.

(a)

(b)

(c)