Review on the amelioration of ZnO and its composites: synthesis and applications

Due to their enhanced biocompatibility and multifunctional capabilities, smart nanoparticles for various enhanced technological applications have attracted considerable attention. These materials are applied in the fields of solid-state physics, electronics, materials science, chemistry, biochemistry, medicine, in vivo imaging and modern drug delivery systems. ZnO nanoparticles have been used as anticancer agents in advanced physical therapies, bone tissue regeneration and nanoantibiotics due to their reduced size, large surface-to-volume ratio, photocatalytic and antibacterial activities and semiconducting capabilities. However, they may exhibit some instability in biological settings as well as unpredictable harmful effects. Doping appears to be a viable way to overcome the aforementioned constraints, allows for the tuning of optical characteristics and expands the usage of ZnO in nanomedicine. ZnO nanoparticles doped with transition metals and rare earth elements are typically prepared via sol–gel, hydrothermal, and combustion techniques. Biomedical uses, including improved antibacterial activities, contrast imaging capabilities, colloidal biocompatibility and stability in biological media, were shown for both dopant types. To serve as a preamble for young researchers in futuristic studies, this article aims to present comprehensive information on the present state of ZnO nanostructures and techniques. This review supports the idea that doping ZnO can improve its biomedical capabilities in comparison to those of its undoped counterparts. The current research also points toward the possibility of a novel use of ZnO nanoparticles in nanomedicine.