We present the results of an experimental study investigating electrowetting effects in nano-suspension drops. Wetting of sessile drops of titanium oxide (TiO2) nano-particles dispersed in deionised water was studied under a DC voltage potential. The presence of nano-particles is found to further enhance spreading of drops when a DC potential is applied. Results are explained based on the change in interfacial energy induced by nano-particle adsorption at the solid-liquid interface. An amendment of the Young-Lippmann equation accounting for the presence of nano-particles is proposed. The electrowetting expression proposed is validated against the experimental data for substrates with various dielectric thicknesses. (C) 2013 AIP Publishing LLC.