Electrochemical Oxidation of Epinephrine and Uric Acid at a Layered Double Hydroxide Film Modified Glassy Carbon Electrode and Its Application

Increasing attention has been paid to layered double hydroxide (LDH) film modified electrode attributing to its desirable properties for fabrication of electrochemical sensor. In this paper, the Zn-Al LDH film modified glassy carbon electrode was characterized by electrochemical methods. The enhanced electrocatalytic currents and well-separated potentials for epinephrine (EP) and uric acid (VA) were observed at the as-prepared electrode. Under selected condition, the differential pulse voltammetry response of the modified electrode to EP (or VA) shows a linear concentration range of 0.5 mu M to 0.3 mM (or 2 mu M to 0.4 mM) in the presence of 10.0 mu M VA (or 20.0 mu M EP). At a signal-to-noise ratio of 3, the calculated limits of detection are 0.13 mu M and 0.66 mu M, respectively. The proposed method has been performed to successfully detect EP and VA in analysis of real samples, such as in EP injection solution and human urine samples.