This paper presents the results about the detection and quantification of dopamine (DA) in presence of ascorbic acid (AA) by using an electrochemical modified gold electrode and an electrochemical and chemical modified gold electrode with a self assembled monolayer of a novel compound, the N-methyl-1-cyclopenten-2-dithiocarboxylic acid. The cyclic voltammetry (CV) and Square Wave Voltammetry (SWV) techniques were using for these experiments.