Selective electrochemical determination of dopamine using Thioglycolic acid modified gold electrode

This study was aimed to investigate the selective electrochemical determination for dopamine based on thioglyolic acid-modified gold electrode. Negatively charged Au electrode surface was created by making Thioglycolic acid film through thiol functional group. Greater oxidation current and less overpotential was observed for the oxidation of dopamine in phosphate buffer solution of pH 8.0 at thioglyolic acid-modified gold electrode than bare Au electrode due to the electrostatic attraction between the negatively charged thioglyolic acid-modified gold electrode surface and positively charged dopamine. The electrochemical behavior of dopamine at the thioglyolic acid-modified gold electrode showed a linear response from 0.05 to 100.0 µM and the limit of detection is 0.01 µM using chronoamperommetry. The proposed thioglyolic acid-modified gold electrode shows good repeatability and promising application in dopamine hydrochloride injection sample.