Enhancement of Dopamine Electrochemical Detection with Manganese Doped Crystalline Copper Oxide
S. Gutoiu, Florina Pogăcean, Lidia Mǎgeruşan, Maria Miclăuş, Oana Grad, Ovidiu Pană, Stela Pruneanu
Abstract
Manganese doped crystalline copper oxide (CuO:Mn) and undoped CuO were prepared at room temperature by the hydrothermal method. The complete physico-chemical characterization of the materials was performed using X-ray diffraction (XRD), transmission/scanning electron microscopy (TEM/SEM), and X-ray photoelectron spectroscopy (XPS). Furthermore, their analytical applicability was tested in electrochemical experiments for a dopamine assay. According to the morphological investigation, the materials had a flat structure with nearly straight edges. The XRD analysis proved the formation of the CuO phase with good crystallinity, while the Mn doping was determined by XPS to be around 1 at.%. Under optimized conditions, at pH 5.0, the CuO:Mn modified electrode (CuO:Mn/SPE) showed a high signal for dopamine oxidation, with a linear response in the 0.1–1 µM and 1–100 µM ranges and a low limit of detection of 30.3 nM. Five times higher sensitivity for manganese doped copper oxide in comparison with the undoped sample was achieved. The applicability of the developed CuO:Mn/SPE electrode was also tested in a commercially available pharmaceutical drug with good results, suggesting that the developed sensor has promising biomedical application potential.