Morphological and voltammetric characterization of redox active nafion thin films fabricated via spin coating method

Chemically modified electrodes were fabricated by depositing thin films (\u3c400nm) of 5% Nafion incorporated with immobilized ruthenium(II) bipyridyl redox mediators on indium tin oxide (ITO) coated glass substrates. The concentration of the redox mediator in the casting solution, according to the ratio with Nafion, and the angular velocity at which the film is thinned out were varied. The corresponding morphological characteristics were investigated and discussed using scanning electron microscopy (SEM). Elemental composition of the films was examined using energy dispersive x-ray (EDX) to confirm successful deposition of the desired thin films. Cyclic voltammetric characterization was also performed to determine the effect of the varied deposition parameters on the corresponding properties of the fabricated modified electrodes such as the transport properties, surface coverage, concentration of immobilized redox mediators within the film and ultimately, the diffusion coefficient