High electrochemical detection of dopamine based on Cu doped single phase hexagonally ZnO plates

Abstract

Dopamine is a chemical that plays a key role in various neurological diseases such as Parkinson's, depression, and some types of cancer. Hence, sensitive detection methods of dopamine are necessary for early discernment of diseases related to abnormal levels. In this study, Cu doped ZnO (Cu/ZnO) nanostructures, immobilized onto the surface of glassy carbon electrode (GCE), have been investigated as a highly efficient electrode material for the electrochemical detection of dopamine (DA). A simple hydrothermal process was used for the synthesis of the ZnO and Cu/ZnO nanostructures. Detailed characterization revealed that addition of Cu on the ZnO changed the morphology of ZnO creating a highly microporous nanostructure. The electrochemical response of DA on the Cu/ZnO/GC electrodes, determined using cyclic voltammetry (CV) and differential pulsed voltammetry (DPV), indicated that on these materials it is possible to achieve lower over-potentials for the DA oxidation and higher catalytic activity. Furthermore, the GCE modified with 50 % Cu doped ZnO showed the most promising performance with high stability in wide range of pH values (2–8 pH), and linear response for DA from 0.1–20 μM with high sensitivity of 2630 nA/μM and detection limit as low as 55 nM. The analytical performance of the developed sensor showed its potential capability for the DA quantification in complex biological systems.