Simultaneous Electrochemical Preconcentration and Determination of Dopamine and Uric acid by Square-Wave Adsorptive Stripping Voltammetry using a Poly(Safranine O)-Modified Glassy Carbon Electrode

Abstract

In this paper we present a new method that allows for the simultaneous identification and quantification of dopamine(DA) and uric acid (UA) by square-wave adsorptive stripping voltammetry. Safranine O was electropolymerised on a glassy carbon electrode and then characterised by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), UV-visible and FT-IR spectroscopy. The electrochemical properties and applications of the modified electrode were studied. In the simultaneous determination of aforementioned two analytes using SW-AdSV, the electrochemical signals were well separated into two oxidation peaks with peak potential differences of 0.176 V (DA-UA). The peaks current are proportional to the concentration of DA and UA over the 0.3-10 mu M and 0.5-20 mu M. When this modified electrode was used to simultaneously determine DA and UA by SW-AdSV, the detection limits for DA and UA were 0.05 mu M and 0.09 mu M, respectively. The prepared sensor may be used as a potential sensing platform for detection of DA and UA under coexistence of ascorbic acid. The poly(SFO) modified glassy carbon electrode showed good stability, sensitivity and selectivity. After optimization of analytical conditions, the proposed modified electrode was successfully applied as a sensor for the simultaneous square wave adsorptive stripping voltammetric determination of DA and UA in real human urine samples.