Integrated of IDEs with TiO2 nanoparticles thin films for pH sensor

The combination of nano/micro technology, biology and metal oxides materials have seen great advances in the development of transducers and biochips for biological and medical fields. In this work, TiO₂ nanoparticles thin films were prepared using sol-gel method and annealed at 400°C to promote nanoparticles crystallization in anatase phase. The influence of surface topologies and uniformity distribution of TiO₂ thin films were investigated using AFM, whereby the surface structural was determined by XRD. The conventional photo-lithography technique was applied in the fabrication of micro-gap interdigitated electrodes (IDEs) with 7 μm gap size between the adjacent fingers. This device will be employed as an electrochemical sensor to detect the bio-molecules thru electrical characteristics. The fabricated micro-gap Au/Ti IDEs gap size was further inspected using the scanning electron microscopy (SEM). Purchased pH buffer solutions which varied from pH4 to pH 12 is dropped on the micro-gap IDEs and the effect on it is investigated for the application in pH measurement.