Simultaneous Determination of Dopamine and Acetaminophen by a Carbon Paste Electrode Doubly Modified with Poly (Pyrrole) and CuO Nanoparticles

An electrochemical sensor was prepared by the modification of the carbon paste electrode (CPE) with a synthesized nanocomposite. The structure and morphology of the nanocomposite which was prepared by combination of poly pyrrole and copper oxide nanoparticles (PPy/CuO) was studied. This nanocomposite showed good electrocatalytic activity; so that the nanocomposite based electrochemical sensor (CPE-PPy/CuO) exhibited an excellent electroanalysis signals toward oxidation of dopamine (DA) and acetaminophen (AC). This effect is concluded from the high conductivity, low electron transfer resistance and catalytic effect of the PPy/CuO. The fabricated sensor had a lower overvoltage and higher electrical current respect to the bare CPE, for both DA and AC. Also, this sensor can resolve the overlapped anodic peaks of DA and AC and therefore it was used in the simultaneous determination. The calibration plots with wide linear ranges and suitable sensitivity was obtained for DA and AC by differential pulse voltammetry. Also good detection limits were found including 0.020 μM for DA and 0.025 μM for AC. Finally, the electrochemical sensor was used for determination in real samples.