RESUMO
A polymer-based carbon paste electrode was constructed by electropolymerized Alizarin Red S (ARS) film on the carbon paste electrode (CPE) surface. The electrochemical properties of poly-ARS/CPE were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was utilized for electrode characterization. The electropolymerization cycles for the construction of the sensor and the supporting electrolyte were optimized. With 0.1 M LiClO4 as a supporting electrolyte, poly-ARS/CPE was able to generate oxidation peaks for anthracene (ANT) and phenanthrene (PHE), that were clearly defined and easily distinguished from one to another when operating in square wave voltammetry (SWV). In the simultaneous detection the linear ranges of ANT and PHE were within 80-1000 µM, with detection limits of 24 µM. The variation of peak parameters with scan rate was investigated to determine the nature of electrooxidation and the number of electrons involved in the electrode process. Poly-ARS/CPE was successfully utilized for the detection of ANT and PHE in different water samples and the obtained results suggested the selectivity, stability and reproducibility of the modified electrode.