A modified glassy carbon electrode was prepared through electropolymerization of caffeic acid in the presence of either carbon nanotubes or nano‐carbon drop cast onto the electrode surface. The voltammetric behaviour of the electrode was characterized using the ortho‐quinone moiety on the caffeic acid unit and the surface loading optimized for current response. The nanocomposite mediated electrode was used for the sensitive detection of glutathione at concentrations as low as 500 nM.