Expanded graphite modified with intercalated montmorillonite for the electrochemical determination of catechol

An expanded graphite electrode (EGE) modified with intercalated montmorillonite (MMT) was developed for the electrochemical determination of catechol. Compared to the bare EGE and the EGE modified with natural MMT, the peak current of catechol on the cyclic voltammograms was significantly improved on the EGE modified with intercalated MMT. The remarkably increased specific surface area of MMT after intercalation plays a decisive role in the electro-catalytic oxidation of catechol. Various important factors such as the type of electrolyte and the content of intercalated MMT which influence the response of catechol on the modified EGE were also investigated in this paper. The amperometric sensor shows a linear response range between 10 and 1000 μM catechol with a correlation coefficient of 0.9987. The detection limit was calculated as 1.13 μM (S/N = 3).