Enhancing Dopamine Detection Using Glassy Carbon Electrode Modified with Graphene Oxide, Nickel and Gold Nanoparticles

A novel and an easy method was developed to fabricate non-enzymatic electrochemical sensor for sensitive detection of dopamine (DA). A composite material contains graphene oxide and nickel nanoparticles was deposited on a glassy carbon electrode (GCE) surface by cyclic voltammetry. Then, gold particles were loaded on the surface of the resulting material via galvanic replacement method in order to obtain Ni-Au bimetallic nanoparticles combined with the electrodeposited graphene oxide (EG). The electrochemical behavior and the structure of the obtained electrode were characterized using scanning electron microscopy, cyclic voltammetry and impedance spectroscopy. The response of the modified electrode for DA detection is linear in the range from 2 x 10(-7) to 10(-4)M, the sensitivity is 0.641 A M-1 and the detection limits is 10(-7)M. As well, it showed a high selectivity in the presence of Uric acid (UA), Ascorbic acid (AA) and glucose. Due to its low-cost, an easy process and great performance, this GCE/EG-Ni-Au(NPs) electrode can be a good candidate for the fabrication of non-enzymatic dopamine sensor. (c) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.