Preparation of Qulnonold Polymer Modifled Electrode by Electrochemical Oxidation of Mercaptohydroquinone

Abstract

It was confirmed that mercaptohydroquinone (H₂QSH) reacts with p-benzoquinone to give bis(2, 5-dihydroxyphenyl) sulfide via 1, 4-addition in the Britton-Robinson buffer (20% Et0H)at room temperature. this fact suggests that 1) H₂QSH is electrolytically oxidized to give mercapto-p-benzoquinone, 2) the oxidation product reacts with H₂QSH to form a. dimer, 2(2 5-dihydroxyphenylthio)-6-mercapto-1, 4-benzenediol, 3) the dimer is oxidized further and 4) H₂QSH, SaHd ds successively to the oxidation product of the dimer. Using a glassy carbon electrode (GC) as the working electrode, stable polymers were obtained by electrolytic oxidation of H₂QSH through alternative oxidation and addition reactions on GC both in acidic and neutral media. The behaviors of this polymer electrode were examined by cyclic voltammetry.