Both p-doping and n-doping processes kinetics were studied by potential steps using different polymers from initial states having different conformational compaction degree. At the chronoamperometric maxima exist, in both cases, a chemical kinetic control. The kinetic coefficient, k, and the reaction order related to the active sites in the polymer chains, beta, decrease for increasing packed conformations of the initial state. Rising packed conformations are obtained at rising cathodic potentials for p-doping polymers, or inside the band-gap for both p- and n-doping polymers. These materials can be used as sensors: their electrochemical responses change with the electrolyte concentration or temperature.