Non-enzymatic flexible glucose sensing platform based on nanostructured TiO2 - Au composite

All over the world the number of people suffering from diabetes and related complications is drastically growing. Therefore, the need for accurate, reliable and stable sensor for monitoring of glucose in human body fluids is becoming highly desirable. In this work we show that material composed of gold layers deposited onto TiO2 nanotubes (NTs) formed onto the flexible Ti foil exhibits great response toward glucose oxidation and can be successfully used as electrodes in non-enzymatic and non-invasive electrochemical sensors. TiO2NTs have been prepared via anodization process followed by calcination at 450 degrees C in order to ensure formation of anatase crystalline phase. Next, gold layers (up to 100 nm) have been deposited on the NTs by means of the magnetron sputtering. The SEM imaging confirmed presence of the well-aligned nanotubes and preservation of their initial architecture after metal deposition for Au thicknesses up to 50 nm. Basing on electrochemical results in the presence of glucose in neutral and alkaline solutions, the optimal Au thickness was found to ensure both the best response and cost-effectiveness. The detection limit of 50 mu M and sensitivity of 45 mu A/cm(2)mM obtained under neutral conditions confirm that prepared material can be used for glucose detection at levels typical for blood, urine or saliva. Moreover, the proposed electrodes exhibit great tolerance to extensive exploitation and multiple bending.