Detection of Escherichia coli using nano sensors irradiated by gamma

Abstract

Manufacturing of zinc oxide and copper oxide nanofilms (ZnO and CuO doped PVA) on glass and silicone n-type substrates using the Sol-Gel method, Analysis and study of the optical, structural and studying the electrical properties (I-V) of ZnO and CuO doped PVA nano thin film, Detection of Bacteria (E. coli), Comparison between the irradiated and non-irradiated nano sensors, thin films was achieved in this study using the Sol-Gel method with differing doses of gamma radiation and multiple layers on silicone and glass substrates. The structural, optical and electrical properties of ZnO and CuO doped PVA thin films have been investigated and studied. The structure of all prepared thin films is hexagonal and monoclinic polycrystalline in nature, according to X-ray diffraction (XRD) data, and annealing temperature improved the crystallinity of the films. Atomic Force Microscope (AFM) images of the prepared ZnO and CuO doped PVA thin films on silicone substrates showed a smooth surface structure. The effect of gamma irradiation on fabricated ZnO and CuO doped PVA nanocomposite thin films for detecting Escherichia coli was investigated. At room temperature, thin films of ZnO and CuO doped PVA were exposed to a source of 60Co-radiation at differing dose concentrations, ranging from 0 to 72 Gray. The structural, morphological, and electrical properties of the sample were investigated using XRD, AFM, UV-visible spectroscopy, and Current-Voltage (I-V) measurements. XRD spectra were taken to detect the formation of crystal phases in all pure ZnO and CuO thin films. The diffraction pattern indicates a high crystalline stability. The surface roughness of the thin films that can be calculated by AFM measurement grew distinct as the gamma radiation increased. The optical absorption property has been determined by UV-visible spectroscopy in the 300-800 nm wavelength range, indicating that the energy difference (Eg) ranges from 3.7 to 3.875 eV with extended layers. The occurrence of E. Coli as pathogenic bacteria in water was observed by measuring the conductivity differences of thin films using I-V measurement. The sensors’ sensitivity was shown to be greater at higher radiation levels.