Effect of Gamma Radiation on ZnO Doped PVA Nanocomposite Thin Films for <i>Escherichia coli</i> Sensor

Abstract

The effect of gamma radiation on fabricated ZnO doped PVA nanocomposite thin films for determination of Escherichia coli has been investigated. Thin films of ZnO doped PVA were exposed to 60Co γ-radiation source at difference dose rate, ranging from 0 to 30 kGy at room temperature. The structural, morphological and electrical properties of the sample were investigated using X-ray diffraction (XRD), Atomic force microscopy (AFM) and Current-voltage (I-V) measurement. The X-ray diffraction (XRD) spectra have been performed to see the formation of crystal phases of all pure ZnO thin films. The diffraction patterns reveal the good crystalline quality and indicate the crystallization of the ZnO-PVA films strongly depends on radiation dose. The roughness of the thin film surface which can be seen by conducting Atomic force microscopy (AFM) measurement became smoother as the gamma radiation increased. The presence of Escherichia coli as a bacterial contamination in water was identified by measuring the changes of conductivity of thin films using current–voltage (I-V) measurement. The sensitivity of the sensors has been observed to be higher at a higher radiation dose.