Electrochemical study on screen-printed carbon electrodes with modification by iron nanoparticles in Fe(CN)64-/3- redox system

The remarkable enhancement of electron transfer on screen-printed carbon electrodes (SPCEs) with modification by iron nanoparticles (Fe-nano), coupled with Fe(CN)(6)(4-/3-) redox species, was characterized with an increase of electroactive area (A(ea)) at electrode surface together with a decrease of heterogeneous. electron transfer rate constant (k degrees) in the system. Hence, Fe-nano-Fe(CN)(6)(3-) SPCEs with deposition of glucose oxidase (GOD) demonstrated a higher sensitivity to various glucose concentrations than Fe(CN)(6)(3-)/GOD-deposited SPCEs. In addition, an inhibited diffusion current from cyclic voltammograms was also observed with an increase in redox concentration and complicated the estimation of A(ea). Further analysis by the electrochemical impedance method, it was shown that this effect might be resulted from the electrode surface blocking by the products of activated complex decomposition.