The electrode surface was readily modified by a drop casting of 5 mg/mL solution of Co3O4 dissolved in 1.0 M potassium hydroxide electrolytic solution. The latter one was chosen because it GNE-7915 allows the formation of a stable suspension of the nanoparticles . The surface modification was electrochemically characterized using CV and EIS (Fig. 6a and b). CV showed an improvement in the electrochemical features of the Co3O4-modified electrode comparatively the bare electrode which can be reasonably ascribed to the Co3O4 introduction which consists on an amelioration in current intensity (Fig. 6a). Moreover, one can see through the CVs that the ipc-to-ipa current ratio is closer to the unity and a diminution in the peak-to-peak separation denoting a substantial amelioration in the reversibility of the electron transfer from [Fe(CN)6]4/3− electrochemical probe to the electrode surface. The latter one was further investigated using EIS which showed a dramatic drop (>90%) in the electron transfer resistance (RCT) ( Fig. 6b) after the modification by the Co3O4 nanoparticles and thus confirming the CV results .