Eu₂O₃@Cr₂O₃ Nanoparticles-Modified Carbon Paste Electrode for Efficient Electrochemical Sensing of Neurotransmitters...

There are ten million people in the world who have Parkinson's disease. The most potent medicine for Parkinson's disease is levodopa (L-DOPA). However, long-term consumption of L-DOPA leads to the appearance of side effects, as a result of which the control and monitoring of its concentrations are of great importance. In this work, we have designed a new electrochemical sensor for detecting L-DOPA using a carbon paste electrode (CPE) modified with Eu₂O₃@Cr₂O₃ composite nanoparticles. Rare earth elements, including Eu, are increasingly used to design new electrode nanocomposites with enhanced electrocatalytic properties. Europium has been considered a significant lanthanide element with greater redox reaction behavior. We conducted a hydrothermal synthesis of Eu₂O₃@Cr₂O₃ and, for the first time, the acquired nanoparticles were used to modify CPE. The proposed Eu₂O₃@Cr₂O₃/CPE electrode was investigated in terms of its electrocatalytic properties and then used to develop an analytical method for detecting and quantifying L-DOPA. The proposed sensor offers a wide linear range (1-100 µM), high sensitivity (1.38 µA µM^-1 cm^-2) and a low detection limit (0.72 µM). The practical application of the proposed sensor was investigated by analyzing commercially available pharmaceutical tablets of L-DOPA. The corresponding results indicate the excellent potential of the Eu₂O₃@Cr₂O₃/CPE sensor for application in real-time L-DOPA detection.