Simultaneous Determination of Dopamine, Uric Acid and Guanine at Polyadenine Film Modified Electrode

A polyadenine film (PAE) modified glassy carbon electrode (GCE) was employed for the simultaneous determination of dopamine (DA), uric acid (UA) and guanine (GA). Experimental results showed that this modified electrode had good electrocatalytic properties for the oxidation of DA, UA and GA. Under optimal conditions, DA, UA and GA reflected their electrochemical response into three separated and well-defined oxidation peaks, whose currents increased 47-, 12-, and 7-fold, respectively, compared with those at bare electrode. Moreover, their oxidation peak currents were linear proportional to their concentrations within the ranges of 2.5 - 75, 10 - 750, and 7.5 - 75 mu mol L-1, respectively, and the limits of detection (LOD) (SIN = 3) were 0.075, 0.35, and 0.025 mu mol L-1, respectively. Compared with a variety of modified electrodes, this designed sensor had a wider linear range and lower LOD. Furthermore, the sensor exhibited good stability and reproducibility.