Aminothiophenol Furfural Self-assembled Gold Electrode Sensor for Determination of Dopamine in Pharmaceutical Formulations

A new Schiff base ۲-aminothiophenol furfural self assembled monolayer (SAM) has been fabricated on a bare gold electrode as a novel sensor for determination of dopamine. Electrochemical impedance spectroscopywas utilized to investigate the properties of the Au ۲-aminothiophenol furfural self assembled monolayermodified electrode (Au ATF SAM-ME) using the [Fe(CN)۶]۳-/۴- redox couple. The electrochemical behaviorof dopamine on the Au ATF SAM-ME was studied by cyclic voltammetry and differential pulse voltammetry,using phosphate buffer solution as supporting electrolyte. The ascorbic acid has no response on the modifiedself-assembly electrode. A calibration curve was obtained for dopamine in a linear range of ۲.۰ × ۱۰-۶ to ۱.۰ ×۱۰-۴ M. The detection limit for dopamine was found to be ۳.۰ × ۱۰-۷ M. The results indicated that the Au ATFSAM-ME could be employed for the determination of dopamine in pharmaceutical formulations.