Electrochemical preparation, characterization, and electrocatalytic studies of Nafion–ruthenium oxide modified glassy carbon electrode

Abstract

Electrochemical synthesis of ruthenium oxide (RuOx) onto Nafion-coated glassy carbon (GC) electrode and naked GC electrode were carried out by using cyclic voltammetry. Electrochemical deposition of RuOx onto Nafion-coated electrode was monitored by in situ electro- chemical quartz crystal microbalance (EQCM). Surface characterizations were performed by scanning electron microscope (SEM) and atomic force microscope (AFM). SEM and AFM images revealed that ruthenium oxide particles incorporated onto the Nafion polymer film. In addition, a GC electrode modified with ruthenium oxide- Nafion film (RuOx-Nf-GC) was shown excellent electro- catalytic activity towards dopamine (DA) and ascorbic acid (AA). The anodic peak current increases linearly over the concentration range of 50 μM-1.1 mM for DA with the correlation coefficient of 0.999, and the detection limit was found to be (S/N=3) 5 μM. Owing to the catalytic effect of the modified film towards DA, the modified electrode resolved the overlapped voltammetric responses of AA and DA into two well-defined voltammetric peaks with peak-to- peak separation about 300 mV. Here, RuOx-Nf-GC electrode employed for determination of DA in the presence of AA. This modified electrode showed good stability and antifouling properties.