Fabrication and characterization of ZnO thin film on interdigitated electrode by sol-gel spin coating method for DNA detection

A transparent semiconductor ZnO thin film was prepared using sol-gel method in which ethanol was used as a solvent. Then, the thin film was deposited on interdigitated electrode. The deposited ZnO thin film was annealed in furnace at 350°C for 2 hours. The influences of surface morphologies and material properties on the ZnO thin film were investigated. The morphologies of the annealed ZnO film were examined using FESEM. XRD result shows that the ZnO thin film was close to single crystalline structure which oriented at (002) plane after annealed. The GNPs-modified ZnO thin film was further use for bio-molecular detection by immobilizing and hybridizing DNA on the GNPs-modified ZnO thin film. The hybridization of target DNA on probe DNA shows that the highest change in capacitance value was approximately 62%.