Facile Green Synthesis of Silver Doped ZnO Nanoparticles Using Tridax Procumbens Leaf Extract and their Evaluation of Antibacterial Activity

Silver and zinc oxide are well known for both their antimicrobial and pro-healing properties. ZnO is a biocompatible and bio-safe material that possesses photo-oxidizing and photo-catalysis impacts on chemical and biological species. ZnO nanomaterials could interact chemically as well as physically in order to exhibit antibacterial activities. Chemical interactions of the ZnO nanomaterials with bacterial cells leads to the photo-induced production of reactive oxygenated species (ROS), formation of H2O2, and the release of Zn2+ ions. In contrast, physical interaction could show biocidal effects through cell envelope rupturing, cellular internalization, or mechanical damage. In this article, we present a green method using Tridax Procumbens leaf extract to synthesize Ag-doped ZnO nanoparticles (NPs) in order to explore the synergistic antibacterial properties of Ag and ZnO nanoparticles against certain gram-positive and gram-negative bacterial strains. The newly synthesized Ag-doped ZnO NPs were characterized by X-ray diffraction (XRD) in order to study the crystalline structure, composition, and purity. Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and Dynamic Light Scattering (DLS) techniques were used to study particle size, shape, and morphology. The XRD and UV studies confirmed the ZnO phase. The absorbance peak around 618 cm-1 - 749 cm-1 in the FTIR spectrum referred to the presence of silver. The surface morphological studies also supported the FTIR result. The synthesized sample exhibited enhanced antibacterial activity irrespective of all tested microorganisms than the standard antibiotic used. The maximum size distribution of particles is found to be around 60 nm from the DLS technique.