In other to establish a synthesis process of nano-structured titanium oxide film for making highly effective biosensor substrate, the preparation of nanotubular on titanium oxide has been carried out through a corrosion reaction in an alkaline solution. The electron microscopic observations revealed that the surface of the titanium was transformed to potassium titanate gel through the treatment with alkaline solution. The titanium could for different nano-structures with corresponded to the concentration of alkaline (potassium hydroxide: KOH) solution. When the concentration of KOH less than 10 M, a porous structured titanium oxide was obtained. On the other hand, when the concentration of KOH in the solution became higher than 10 M, we could obtain nanotubular structured titanium oxide. These nano-structured titanium oxide films may be applied for highly effective biosensor by immobilization of biomolecules on the surface. (C) 2009 Elsevier B.V. All rights reserved.