Highly selective and sensitive dopamine and uric acid electrochemical sensor fabricated with poly (orotic acid)

Abstract

A novel dopamine (DA) and uric acid (UA) electrochemical sensor (poly-OA/CPE) was fabricated by electrochemical polymerization of orotic acid (OA) on a carbon paste electrode (CPE). The sensor was characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) and the electrochemical behaviors of DA and UA were investigated. The experimental results illustrated that the sensor has an excellent electrocatalytic activity towards the oxidation of DA and UA. By using differential pulse voltammetry (DPV) method, low detection limits (S/N=3) of 0.08μM and 0.28μM for DA and UA were obtained, with the linear calibration curves over the concentration range of 0.31–15.21μM and 17.71–141.01μM for DA and 0.82–11.32μM and 13.62–200.62μM for UA, respectively. Moreover, the sensor exhibits good selectivity and sensitivity toward simultaneous determination of DA and UA. The practical analytical utility is illustrated by the determination of DA in pharmaceutical samples without any preliminary treatment.