Microfluidic fuel cells are a low-power demand fuel cells which work without the need of a physical membrane and have a wide range of potential applications. Biological catalysts such as immobilized enzymes can be used in electrodes to carry out the oxidation processes of different organic fuels using the immobilization technology of enzymes; they are carried out under moderate conditions of pH and temperature, and the specificity of the catalytic reactions. The alcohol dehydrogenase enzyme has been used for the development of bioanodes for the oxidation of different alcohols such as ethanol and methanol. In this work, the immobilization of this enzyme was carried out using nanotubes of titanium dioxide for the development of electrodes for an air-breathing microfluidic fuel cell. TiO₂ nanotubes has excellent properties such as pH resistance, superior mechanical strength, good biocompatibility making it a great candidate for the process of immobilization of the enzyme alcohol dehydrogenase. TiO₂ nanotubes were fabricated by electrochemical anodic oxidation on Ti foils. The foils were pre-treated with sand-paper, thereafter immersed in ethanol, placed in ultrasonic bath, dried under N₂ flow. An ethylene glycol-based solution with a concentration of 0.1M NH₄F (96% purity, Alfa-Aesar) and 2% w/w deionized water was used as electrolyte. The anodization times used was 1 h with a voltage step of 60 V via a power source. Using this nanostructure, the enzymatic electrode was constructed using a catalityc ink with enzyme, tetrabutylammonium bromide and Nafion to carry out the immobilization process. We carried out the characterization of the electrode developed by means of different electrochemical and kinetic techniques, where it was demonstrated that the enzyme is present and active in the electrode, as well as its capacity to oxidize ethanol. Then the bioanode was evaluated in the microfluidic device also using an inorganic cathode of Pt / C, obtaining a good performance over an open circuit potential greater than 0.93V.