Metal oxide thin film for chemiresistive biosensing applications

Zinc oxides (ZnO) thin films have obtained popularity and explored for several optoelectronic applications attributed to their unique properties, such as wider bandgaps coupled with high exciton binding energies. They are transparent, thin, homogeneous, chemically stable, non-toxic, easy to prepare and cost-effective films and can be grown on substrates through sol-gel depositing methods followed by heat treatments. In the present work, we developed ZnO thin film-based device for biosensing applications using two probe measurement set-up. ZnO thin films using Zinc acetate dihydrate (Zn (CH3COO)2 2H2O),2-methoxy ethanol (CH3-O-C2H5) and Monoethanolamine (MEA) as metal alkoxide precursor, solvent and sol stabilizer respectively. The thin film was deposited on the glass substrate and annealed at 500 C for better crystallinity. Structural, morphological and optical characterizations have been carried out using X-ray Diffraction, Atomic force microscopy (AFM) and UV-VIS spectrophotometer to confirm the crystallinity, orientation, surface morphology, size distribution and transparency of ZnO thin film. Metal electrodes were deposited on ZnO thin film and tested using two probe measurement set-up for various concentrations of vitamin B6 molecules.