Non-enzymatic glucose sensor using nanostructured copper oxide thin films deposited by spray pyrolysis

Thin-film thickness effect on glucose sensitivity for a non-enzymatic sensor is affected by two main factors, film ' s conductivity, and roughness. The thin-film thickness effect is studied with copper oxide films grown by spray pyrolysis. The film is deposited with thickness in the 83 <= tau film <= 892 nm range on a nickel electrode and employed for glucose sensing in a three-electrode system as a working electrode. As the film thickness increases up to 434 nm, the signal stability and sensibility improve. For a greater thickness, the glucose sensibility starts to decrease smoothly. The sensibility increment from the thinnest film to our best condition is twofold from 0.25 to 0.47 mAmM-1/cm2, and a lineal behavior is observed for a wide glucose concentration range of 0-8 mM. This work shows that a simple solution-based technique such as spray pyrolysis can be employed to obtain functional glucose sensors.