The Cadmium sulfide/Ethylene-diamine-tetra-acetic acid (CdS/EDTA) nanostructure thin film was prepared on a glasssubstrate using spin-coating method and it was used for gas sensor applications. The structure properties of CdS/EDTA werecomparatively characterized. The nanostructured thin film was found both in hexagonal and cubic structure with an averagecrystallite size of 41 nanometer (nm). The stretching and vibration mode of CdS/EDTA was confirmed through Fouriertransform infrared spectroscopy. The surface morphology of the nano particles was investigated using scanning electronmicroscope, which showed uniformly distributed crystalline surface. The values of band gap energy for CdS and CdS/EDTAare respectively, 4.20 and 4.17 eV. The Photoluminescence spectra of the CdS/EDTA films were exhibited green and yellowband emissions. Oxygen was suitably tailored to verify the sensor response over a concentration range of 20-100 ppm at roomtemperature. The observed results reveals that the performance, response, and recovery time of sensors were increased bychelating agent of CdS/EDTA thin film.

Keywords: Spin coating method, Thin films, Gas sensor, AFM