Performance of Impedimetric Biosensors Based on Anodically Formed Ti/TiO2 Electrodes

Abstract
The advantages and limitations of impedimetric sensors based on Ti/TiO2 architectures are described. Titanium dioxide (titania) was potentiostatically formed onto titanium electrodes of 2 mm diameter, at 10 and 30 V in 1 M H2SO4. The thickness of the titania layers was ellipsometrically determined to be 30 and 86 nm respectively and they are highly insulating with charge‐transfer resistances in the MΩ range, as they were measured with electrochemical impedance spectroscopy under specific experimental conditions. Low voltage anodization (25 V), anatase is the predominant form. SEM images are indicative of quite smooth, compact coatings without any severe cracks.