Antibacterial activity of In-doped ZnO nanoparticles

Undoped and In-doped zinc oxide (ZnO) nanoparticles have been synthetized by sol gel technique. The In doping concentration was ranged from 0 to 5 at.%. The prepared nanoparticles structural and morphological properties have been investigated by means of X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The photoluminescence (PL) spectroscopy was used to determine the electronic defects in the samples band gap. The antibacterial activities of the synthetized nanoparticles have been tested against Gram negative and positive bacteria's referring to the inhibition zone radius measurement. The obtained results indicated that In dopant improves its antibacterial activity. The antibacterial activity improvement with In doping effect is attributed to the enhancement of electronic defects including vacancy defect V-zn and interstitial defect Z(ni) with In doping. These defects behave as electrons and holes source necessary for reactive oxygen species (ROS) responsible for bacteria's destruction. We noticed that the prepared ZnO nanoparticles exhibit a low antioxidant activity, this is attributed to the bonded hydrogen charge transfer crystal screening.