When stored in air, the p-styrenethiol tends to degrade, as seen by the formation of a white amorphous solid when the degraded thiol is taken up in ethanol. This polymer could act to lower surface coverage of active vinyl groups by assembling at and passivating the gold surface. The formal potential of the Fc/Fc + redox couple on the pCOT film is 0.417 V, a value indistinguishable from the potential of dissolved Fc/Fc + at a bare gold electrode in the same electrolyte. By contrast, Fc/Fc + at the poly(norbornene) brush has a ca. 80 mV overpotential (0.5V formal potential) and a 4x lower electrochemical surface coverage. The lower electrochemical surface coverage to the poor electronic communication between the redox-active ferrocene endgroups and the electrode surface; the actual coverage of ferrocene groups in the pNb film is expected to be higher since the polymerization is known to have active catalyst chain ends at this time point. The ferrocene peak in the pNb film is likely due to the ferrocene groups tethered by the shortest chains to the surface, which can undergo an electron transfer reaction with the electrode via direct tunneling. In the doped pCOT film, nearly all the Fc should be active due to the metallic conductivity of doped polyacetylene.