The reaction of 1,4-benzoquinone and 1,4-naphthoquinone with β-thiopropionic acid yielded 3-[(3,6-dioxocyclohexa-1,4-diene-1-yl)thio]propionic and 3-[(1,4-dioxo-1,4-dihydronaphthalene-2-yl)thio]propionic acids, respectively. These compounds were used to modify oligonucleotides to allow their electrochemical detection on the surface of Au electrodes using cyclic voltammetry. Electrochemical reduction of the corresponding amides, modeling the bonding of the redox-active labels with molecules that are not electrochemically active, was also studied.