Nanoscience and nanotechnology became a distinguishable and multidisciplinary field of research with emerging applications. In the field of metal oxides, the discovery of superconductive oxides, and oxides with large magnetoresistance has raised great attention, especially to those from transition metals. Metal oxides benefit from the large electronegativity of the oxygen to induce strong electron connections with the nearby atoms, which affects the chemical properties and surface energy of the materials. Chemical synthesis of metal oxides nanoparticles allows a good control of the structure and morphology of the particles as well as the reduction of the processing temperature. Considering all, different electrochemical devices based in tungsten oxide and gallium-indium-zinc oxide nanoparticles were produced, characterized and compared with literature. Tungsten oxide electrodes were applied in electrochromic devices and (bio)sensors, while gallium-indium-zinc oxide as semiconductor in electrolyte-gated transistors.