Dopamine Detection using Mercaptopropionic Acid and Cysteamine for Electrodes Surface Modification

Gold electrodes are often not suitable for the dopamine measurements as dopamine creates a non-conducting polymer layer on the surface of the electrodes, which leads to the increased amount of electrode passivity with the gradual increase in voltammograms measurement. This work presents the impedance spectroscopy and cyclic-voltammetry comparitive study for dopamine detection with two modi[fi]cations for the surface of Au electrodes i.e., (1) Cysteamine and (2) Mercaptopropionic Acid (MPA) for thermally bonded and ultrasonically welded micro[fl]uidic chips respectively. The effects of optimized tubing selection, bonding techniques, and cleaning methods of the devices with KOH solution played crucial role for improvements in dopamine detection which are observed in results. Furthermore, comparison for the modi[fi]cation with unmodi[fi]ed chips, and [fi]nding the unknown concentration of dopamine solution using [fl]ow injection techniques is also illustrated.