An electrochemical sensor for sensitive detection of dopamine based on MWCNTs/CeO2-PEDOT composite

Abstract

In this study, firstly, multi-walled carbon nanotubes (MWCNTs) were electrochemically deposited on a glassy carbon electrode (GCE) and, secondly, this was modified with nanoceria-poly(3,4-ethylenedioxythiophene) (CeO2-PEDOT) composite prepared according to the chemical synthesis process in the presence of sodium dodecylsulfate (SDS). The CeO2-PEDOT composite was characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The MWCNTs/CeO2-PEDOT modified electrode was used for the sensitive analysis of dopamine (DA) in the presence of uric acid (UA) and ascorbic acid (AA) for the first time. Compared with a bare GCE, the MWCNTs/CeO2-PEDOT modified GCE exhibited a more effective electrocatalytic performance with regard to the oxidation of DA. Under optimum conditions, the prepared GCE/MWCNTs/CeO2-PEDOT sensor showed two wide linear ranges of 0.10–10 μmol L−1 and 40–400 μmol L−1 with a good detection limit of 0.03 μmol L−1. Important effects of interferences such as Ca2+, K+, Na+, glucose, urea, sucrose, citric acid and cystine were not observed on the differential pulse response of dopamine for the prepared sensor. In addition, the sensor designed as a new platform was successfully utilized for the electrochemical analysis of DA in pharmaceutical samples.