Square-wave voltammetry and square-wave voltacoulommetry applied to the study of the electrocatalytic behaviour of surface confined myoglobin

Analytical previous results corresponding to square-wave voltammetry (SWV) and square-wave voltacoulommetry (SWVC) have been applied to the electrochemical characterization of myoglobin immobilized at a self-assembled monolayer of l-cystine on a gold electrode and its electrocatalytic activity towards the oxidation of sodium ascorbate. The obtained results have been compared with those previously reported in Langmuir (2011) 27:2052-2057 by using cyclic voltammetry. It has been shown that double layer effects can be easily removed in SWV and SWVC techniques. Accurate values for the thermodynamic and electrochemical kinetic parameters have been obtained by assuming dispersion in the formal potential of the redox center, and a value k (c) 'aEuro parts per thousand= 1.37 x 10(5) M-1 s(-1) has been found for the catalytic constant.