A review on biogenic synthesized zinc oxide nanoparticles: synthesis, characterization, and its applications

Nanotechnology is the most innovative field of the twenty-first century. Worldwide, intensive research is being done to commercialize nano products. Due to their unique or improved physical and chemical properties relative to bulk material, nanomaterials, especially nanoparticles have seen an enormous interest over the past few decades. As environmentally benign alternative nanoparticles are currently being produced "biologically" by means of plant or microorganism-mediated synthesis. Due to its outstanding biocompatibility, affordability, and low toxicity, and cost-effectiveness, ZnO NPs have emerged as one of the most widely used metal oxide nanoparticles in various applications. Interestingly, due to its multiple medical, health, environmental, and economic advantages, the green technique of synthesis employing plant materials has been discovered to be suitable for the production of ZnO nanoparticles. A variety of characterization methods have been used to assess the characteristics of ZnO NPs produced with green strategies, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy and others. The value of these techniques reveals important information about the structural, morphological, and optical characteristics of ZnO NPs. In order to support future biomedical and other research, this review provides an overview of recent developments in the green synthesis of ZnO NPs with a focus on natural sources such as plants, bacteria, fungi, and algae as well as their characterizations, and various applications, including, antimicrobial, anticancer, antioxidant, photocatalytic, anti-inflammatory, anti-diabetics, and anti-aging applications.