Electrochemical characterization of screen-printed carbon electrodes by modification with chitosan oligomers

The kinetics on the current amplification of the disposable screen-printed carbon electrodes (SPCEs) by modification with chitosan oligomers (COs), coupled with the Fe(CN)(6)(3-/4-) redox system, were characterized with the variation of electron-transfer rate constant (k degrees) and the electroactive area (A(ea)) at electrode surface. The nonlinear response characteristics of peak currents with increase in Fe(CN)(6)(3-) bulk concentrations complicated the estimation of A(ea) in cyclic voltammetric analysis. Upon the modification with COs, the rate constant of SPCEs was not much influenced and the current amplification was characterized with the increase of a better estimated A(ea), obtained from electrochemical impedance measurements and verified with the reciprocal of electron-transfer resistances linearly proportional to the Fe(CN)(6)(3-/4-) bulk concentrations. It is hereby provided for all evaluation of the carbon based electrodes with modification.