Study of electrocatalytic processes at mediator modified interfaces with reciprocal derivative chronopotentiometry with exponential time current

Electrocatalytic processes taking place at a modified interface have been studied by considering reciprocal derivative chronopotentiometry with an exponential time current. This technique presents an enhanced sensitivity for this reaction scheme which, under adequate conditions, surpasses to that of cyclic voltammetry. Moreover, it allows peak shaped signals to be obtained, even for very high pseudo catalytic rate constants, and also enables a quasi stationary behaviour to be reached very quickly, for which a linear dependence between the peak height and the “coupled pseudo first order rate constant” (ω+k) is obtained, with k and ω being respectively, the chemical rate constant and the exponent of the exponential time current. The experimental verification of the theoretical predictions has been carried out by analysing the electrocatalytic oxidation of NADH at a Dopamine-Edge Plane Pyrolitic Graphite modified electrode.