Zinc Oxide Nanoparticles: Different synthesis approaches and applications

Abstract

Nanotechnology deals with the synthesis and usage of materials with nanoscale dimension (1-100 nm). Nanoscale dimensions of the particles provide large surface to volume ratio and thus very specific properties. Synthesis of zinc oxide nanoparticles (ZnO NPs) has gained prime importance in recent arena due to its high excitation binding energy and large bandwidth and it has potential applications like anti-diabetic, antibacterial, anti-inflammatory, antifungal, wound healing, antioxidant and optical properties. Zinc (Zn) is a common mineral element in nature which plays an immense role in many biological processes. It is defined as an essential trace element or micronutrient which is very much crucial for the normal growth and the development of all higher plants as well as animals. Zinc directly involves in enzyme function associated with the photosynthesis and energy process in plants. It also plays an important role in maintenance of membrane integrity, formation and production of growth hormone, insulin, thyroid etc. Due to the involvement of large rate of toxic chemicals and requirement of extreme environment, chemical and physical methods of nanoparticle synthesis often became inappropriate. Whereas, green methods are used in a wide range of biological samples including plants, fungus, bacteria, and algae, which act as both reducing and capping agent. Biologically synthesized zinc nanoparticles have been reported for versatile applications in the field of medicine and pharmacy, for bio-imaging and bio-sensor production, in gene therapy and drug delivery system. Zinc nanoparticles also play vital role in agricultural sector including plant growth and development, enhancement of crop yield and post-harvest processing. In spite of being great potential of ZnO NPs for abiotic and biotic stress management, research works in this field is considerably less. This review described the summary of the recent works in the synthesis mechanism, characterization techniques, and applications of biosynthesized ZnO NPs in medicine and agriculture with special reference to application on plant growth, development and abiotic stress management.