**Abstract**

Green chemistry for the synthesis of different nanoparticles (NPs) from metal has become a new and promising field of research in nanotechnology in recent years. The inspire applications of metal oxide NPs have attracted the interest of researchers around the world. Various physical, chemical and biological methods in material science are being adapted to synthesize different types of NPs. Green synthesis has gained widespread attention as a sustainable, reliable, and eco-friendly protocol for biologically synthesizing a wide range of metallic NPs. Green synthesis has been proposed to reduce the use of hazardous compounds and as a state of a harsh reaction in the production of metallic NPs. Plants extract used for biosynthesis of NPs such as silver (Ag), cerium dioxide (C2O2), copper oxide (CuO), Gold (Au), titanium dioxide (TiO2), and zinc oxide (ZnO). This review article gives an overview of the plant-mediated biosynthesis of NPs that are eco-friendly and have less hazardous chemical effects.

**Keywords:** biosynthesis, metallic nanoparticles, plant extract

## **1. Introduction**

In the last decade, novel synthesis methods for nanomaterials such as quantum dots (QDs), carbon nanotubes (CNTs), graphene, and their composites have been an interesting area in nanotechnology [1]. Despite the progress of the use of small metallic materials listed as nano, the debate still continues in many aspects associated with this new technological revolution. The conceptual beginnings of green chemistry and nanotechnology are among the great scientific developments that have influenced the design of experiments with the goal of environmental protection. Now the reduction in size of green chemistry and nanotechnology is one of the great scientific developments which are to preserve the environment with experiments [2]. Nanoparticles are the most fundamental component in the making of nanostructures. They are much smaller than the everyday objects around us governed by Newton's laws of motion but larger than an atom or a simple molecule that is the subject of quantum mechanics [3]. Nanoparticles exhibit specific properties that depend on their shape, size, and morphology and enable them to interact with plants, microbes, animals [4]. Nanoparticles are a subclass of ultrafine particles with a length of more than 1 nm and less than 100 nm in two or three dimensions and which cannot exhibit size-related depth properties

that can vary the NP often their morphological or physical. Their application in controlling microbial growth in green synthesis of NPs and electronics, catalysts, drugs, and biological systems has made them eco-friendly [5]. 'Green Synthesis' is attracting a lot of attention in current research and development on materials science methods and technology. Science will basically make green synthesis of nanomaterials through regulation, control, cleaning and therapeutic process. Some basic principles of its environmental friendliness can thus be explained by several factors such as waste prevention, pollution reduction, and the use of safe non-toxic solvent as well as renewable [6]. Nanoparticles have many applications in several fields, such as microelectronics, hydrogen storage ferrofluids, catalytic systems, and chemical nanosensors as well as nanomedicine, agriculture, food science, and energy [7]. The metallic nanoparticles have unique properties that are different from fine-grained materials which use for many agricultural, industrial, and domestic applications, resulting in increased demand and production of nanoparticles. The list of nano-based commodities silica, iron, titania, alumina, and zinc oxide [8]. These types of NPs are the most white pigment and are being used in many products such as paints, plastics, paper, etc. [9] as well as chromosomal mutations in *Vicia faba* plants [10]. The number of multidrug-resistant bacteria and viral strains has been steadily increasing due to mutation, pollution, and changing environmental conditions are trying to develop drugs for the treatment of this microorganism infection to protect against this disease. Metal Nanoparticles have been found to be effective in inhibiting the growth of much infectious bacterial silver and occupy a prominent place in the category of Ag NPs metals used as antimicrobial agents [11]. Green synthesis methodologies based on biological precursors depend on various reaction parameters such as solvent, temperature, pressure, and pH conditions for the synthesis of various nanoparticles, broadly based on the availability of effective phytochemicals in various plant extracts. The leaves contain ketones, amides, terpenoids, carboxylic acids, aldehydes, flavones, phenols, and ascorbic acids that are capable of reducing the metal salts into metal nanoparticles [12]. *Chrysanthemum carinatum* is herbaceous perennial plant have deeply tapering leaves and large white flowers on the wall and extracts play a very important role in reducing and stabilizing agents that reduce cost production and environmental impact [13, 14].
