Harnessing Nature’s Green Potential: Nanotechnology Driven Fabrication of Plant-Derived Nanoparticles

Millions of tons of metallic nanoparticles (MNPs) are synthesized each year and used in various fields like nano-enabled devices, personal care, medicine, food, and agriculture. The reaction chemicals and processes employed in the industrial synthesis of MNPs are well acknowledged to be hazardous to the environment.Green synthesis has been recommended as a means of minimizing the usage of harmful substances and adverse chemical modification in the synthesis of MNPs. Extracts of organic chemicals, microorganisms, plants and plant-derived materials have all been employed as reducing agents in green synthesis.One of the most efficient, easy, cost-effective, and environmentally acceptable techniques for reducing the usage of toxic chemicals is to employ plant extracts in the synthesis of MNPs. Several eco-friendly procedures for the fast production of MNPs have been reported by utilizing aqueous extracts of plant components including the leaf, bark, flower, peel, shoot, tuber, resin, roots etc.Every year, new scientific publications are released, with each one highlighting the advantages of the green methodover classic synthesis. However, over two decades after the preliminary reports about the new technique exploded, commercial production of green-synthesized nanoparticle (NPs) does not appear to have found a means to scale up. This review covers green MNPs synthesis from various plant extracts and their potential applications as antimicrobial agents covering the literaturesince 2015. While highlighting the use of MNPs in a variety of fields and the potential impact of phytochemicals associated in MNPs production.


Introduction
With great applications in science and technology, nanotechnology is quickly becoming a rapidly growing subject and gaining much interest.Also, MNPs have sparked a lot of interest in the scientific community and in industry.NPscan be produced using a variety of process like chemical, physical, biological, and hybrid methods shown in Figure 1.The physical and chemical techniques used to prepare MNPscan be further classified as either top-down (Meyer et al., 2006) or bottom-up approaches (Scheuer et al., 2001).However, physical and chemical methods, can generally be considered to be expensive and unsafe due to the need for special equipment, high energy and chemical substances that are flammable, toxic and corrosive (Shahwan et al., 2011).At the same time biological method classified as microbial based and plant-based synthesis.Microbial-based synthesis is also a green and safe option, but it takes time to culture microorganisms in the lab and then synthesize NPs with them, and handling with microbes can be hazardous to individuals, because microbes can easily multiplicate and infect humans also.Aside from chemical and physical synthesis, the green route to NP production Nanomedicine has really been popular since ancient times, when Vaidya utilized organometallic ethnonanomedicine named bhasma.Bhasma, which literally translates to "ash," is a type of Ayurvedic herbomineralometallic substances of nanoscale dimensions (typically 5-50 nm, as determined by contemporary microscopic and spectroscopic methods).Metal-based medications operate best when they are transformed from their original metal state to an oxide state.The manufacturing method, known as "Bhasmikarana," changes the metal from its zerovalent state to a higher oxidation state, removing the metal's poisonous character and creating the transition metal nanobhasma with great therapeutic potential (Sharma and Prajapati, 2016)  According to Bose et al., the leaves of Pistidum guajava contain flavonoids that can work as a reducing and capping agent for synthesizing silver NPs (Bose and Chatterjee, 2016).Similarly, H + ions produced in conjunction with NAD were responsible for the formation of nano silver particles as well as water soluble antioxidative agents during glycolysis is produced (e.g.ascorbic acids).These antioxidative compounds were particularly involved in silver ion reduction (Jha et al., 2009).Plant-based NPs synthesis is faster, safer and lighter; it synthesized at low temperatures; and it requires few and environmentally friendly components (Chung et al., 2016).Plant-based NPs have gotten increased Harnessing Nature's Green Potential: Nanotechnology Driven Fabrication of Plant-Derived Nanoparticles Available online at: https://jazindia.com-1398 -attention as people become more concerned about the environment.Furthermore, the use of safer solvents, less harmful reagents, easier reaction conditions, practicality, and flexibility in usage for medical, surgical and pharmaceutical applications are all advantages of employing plants to NPs synthesis (Halim et al., 2011).As people become more concerned about the environment, plant-based NPs have garnered more attention.Furthermore, using plants to synthesize NPs has several advantages, including the use of cleaner solvents, less toxic reagents, simpler reaction conditions, practicality and versatility in use for medicinal, surgical, and pharmaceutical purposes.Plant Mediate Biogenic Synthesis Microorganisms are capable of producing many unique nanostructures.This has led scientists to become more interested in utilising these microbes to synthesise nanostructures for various applications.Inorganic molecules can be generated by bacteria and fungi by biologically mediated and induced synthesis (Moitra;Alafeef et al., 2020).By controlling the biological synthesis, nanostructures of desired geometries and composition can be formed.Despite the accuracy of the nanoparticle physicochemical synthesis, biological synthesis of nanoparticles is still limited in terms of particle geometry controllability and process scalability (Fang, Wang et al., 2019).Nevertheless, biologically induced synthesis has allowed scientists to synthesise inorganic nanoparticles using common metal precursors (Grasso, Zane et al., 2020); while also offers a wide range of composition.

From Leaf
The leaf is the vascular plant stem's main lateral appendage, generally carried above ground and specialized for photosynthesis, transpiration, guttation and other functions.leavesproduce many bioactive compounds for plant defense and various phytochemicals which helps is formulation of green NPs.The interesting fact is plants also produce NPs on leaves itself by metal salt accumulates on the ground and is stored in the storage portion, although it is difficult to separate.It Leaves extract was reported to be used as a catalyst in the production of NPs.The leaves of Centella asiatica, Murrayakoenigii, Alternanthera sessilis and a variety of other plants were studied.P. nigrum leaves have recently been discovered to have an essential bioactive component that is used in the environmentally friendly manufacturing of NPs.Ponarulselvam et al. 2012 using ultraviolet-visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM) and X-ray diffraction, characterization of 35-55nm AgNPs from Catharanthus roseus Linn.leaves were carried out, and ant plasmodial activity against P. falciparumis was investigated.Ramteke et al. 2013 prepared 18nm AgNPs using Ocimum sanctum (Tulsi) leaf extract, which is rich in eugenols, terpenes and other aromatic compounds that stabilize the NPs and antibacterial efficacy against S. aureus and E. coli was investigated (Ramteke et al., 2013).Moorthy et al. 2015 synthesized MgONPs which ranges between 252-7nm and tested effect on seed germination on Cicer arietinum and Solanum lycopersicumleaves.The antibacterial activity of the generated NPs was tested using the disc diffusion technique against E. coli, B. subtilis, S.aureus and Klebsiella sp.(Sengupta et al., 2021).Till date, a numerous number of leaves extract have been utilized for the biosynthesis of various NPs as shown in table 1.

From Seeds
An embryonic component of a plant that is covered by an outer coat is known as a seed.Seeds have a critical role in the reproduction process in all plans.Nutrients, proteins, and polyphenols, as well as other nutrients and bioactive compounds, abound in plant seeds.These bioactive compounds are essential in the bio fabrication of NPs.AgNPs mediated by Sinapis arvensis seeds were shown to limit the mycelium development of the fungus N. parvum by more than 83 percent.Within 50 days of the reaction, inductively coupled plasma spectrometry (ICP) examination demonstrated a full decrease of Ag + to Ag 0 with a conversion rate of greater than 95% (Khatami et al., 2015).According to Mittal et al., 2013 fenugreek seed extract contains a lot of flavonoids and other natural bioactive components including lignin, saponin and vitamins.These bioactive components are the best reactant and surfactant for chloroauric acid.COO (carboxylic), C=N and C=C functional groups are present in the seed extract.
The functional group of metabolites acts as a surfactant for gold NPs and flavonoids can aid in the electrostatic stability of gold NPs.Xu et al., 2014 utilized grape seed extract for the synthesis of silver NPs of 25-35 nm.Bactericidal was tested against various ocean pathogenic bacteria; However, only four bacteria, V. alginolyticus, V. anguillarum, V. parahaemolyticus and A. punctate showed significant inhibitory action.Sumitha et al., 2018 reported bio-reduction of AgNO3 to AgNPs using Duriozibethinus seed extract which have saccharides that inducesbio-reduction and amino acids which stabilized the synthesized AgNPs.Bactericidal activity was evaluated against a variety of harmful bacteria and the NPs were found to be more effective against S. typhimurium, S. haemolyticus and S. aureus than B. subtilis, E. coli and S. typhi.However, when compared to the medicine Gentamicin, the synthesized NPs demonstrated reduced inhibition against all of the harmful bacteria listed, even at a lower dosage of Gentamicin.The effectiveness of AgNPs as an antibacterial agent is said to be highly reliant on the form of the NPs, according to several studies.Alfuraydi et al. 2019 fabricate 6.6 nm to 14.8 nm spherical shape SCAgNPs from Sesamum indicum, L. A cytotoxicity assay was conducted on a human breast cancer cell line using two different dosages of SCAgNPs (2.5 and 7.5 g/mL) (MCF-7 cells).Initially, a 2.5 g/mL dosage treatment resulted in 72.02 percent viable cells, 11.81 percent apoptosis, 15.18 percent late apoptosis and 1.20 percent necrosis.Interestingly, 7.5 g/mL caused significant cytotoxicity, with 56.97 percent viable cells, 7.42 percent apoptosis, 31.19 percent late apoptosis, and 4.85 percent necrosis.Table 2 summarizes the many seeds extracts that have been used for the production of various MNPs to date.

From Flowers
Harnessing Nature's Green Potential: Nanotechnology Driven Fabrication of Plant-Derived Nanoparticles Available online at: https://jazindia.com-1414 -Flower is the reproductive structure found in flowering plants and also contain different phytoconstituents Alkaloid, Flavonoids, Phenols, Saponi, Steroids, Tannins etc that give numerous benefits, including antimicrobial, anticancer and antioxidant activities and the synthesis of MNPs with plant sources improves the efficacy with a smaller quantity.In NP synthesis, jasmine flower extract serves as a capping and stabilizing agent (Aravind et al., 2021).Silver, zinc and gold NPs produced with the flower extract of Rhanteriumepapposum are effective cytotoxic and antifungal agents (Qhtani et al., 2020).Nauzi et al. 2011 produce 10nm AuNPs from Rose hybrida petal extract at room temperature.Rose flower extract is high in carbohydrates and proteins, which are the primary sources of tetrachloroaurate salt which reduce and for bulk AuNPs.Padalia et al., 2015 used Tagetes erecta flower extract to bio-reduce AgNO3 to manufactured AgNPs and their bactericidal effect against Grampositive and Gram-negative bacteria such S. aureus, B. cereus, E. coli, P. aeruginosa, C. glabrata, C. albicans and C. neoformans is investigated.MNPs have been synthesized using Catharanthus roseus and Clitoriaternatea flowers and the synthesized NPs have been demonstrated to be efficient against hazardous pathogenic bacteria as well as medicinally useful.Nyctanthesarbortristis were utilized to make gold NPs using a green chemistry process (Kuppusamy et al., 2016).Similarly, AuNPs of 60-70 nm were produced by utilizing an aqueous extract of Mirabilis jalapa flowers as a reducing agent.Flower extract of Caesalpinia pulcherrima (Gogoi et al., 2015;Chanda, 2016) Alcea rosea (Inezhad et al., 2017) and Argemone Mexicana (Vinay et al., 2017) used for production of biogenic AgNPs has also been reported.Table3 summarizes the numerous floral extracts that have been used for the production of various MNPs to date.

From Root
Tannins, steroids, saponins, polysaccharides, quinones, alkaloids, flavonoids, carbohydrate and coumarins are all found in the root extract.To make 10 to 15 nm and spherical AgNPs, researchers employed Alpinia calcarata root extract.The adsorbed components on the surface of NPs were predominantly flavonoid in nature, according to NP analysis.Furthermore, NPs were tested for cytotoxicity against a variety of cancer cell lines and NPs containing 0.2 to 12 g/mL demonstrated excellent toxicity.The IC50 values of NPs against MCF-7 and U-87 cell lines were 4.91 and 8.23 g/mL, respectively (Mittal et al., 2015).Berberis asiatica root extract contains phytoconstituents which were used to make 9.8 nm AgNPs with antibacterial activity against K. pneumoniae, E. coli, S. aureus and S. typhimurium, as well as synergistic activity against K. pneumoniae and are used to treat a variety of illnesses.It's also been demonstrated in animal experiments to be a hepatoprotective, anti-diabetic, antiinflammatory and antibacterial agent (Muddassir et al., 2017).Pugazhendhi et al. 2015 used aqueous root extract of Alpinia calcarataas a reducing and stabilizing agent.The morphologies of AgNPs were studied using high-resolution transmission electron microscopy (HRTEM).The components found in the A. calcarata extract were identified using inductively coupled plasma-optical emission spectrometry (ICP-OES) and Fourier transform infrared spectroscopy.Antimicrobial activity was also tested, with the results confirmed using the resazurin dye reduction assay method (Pugazhendhi et al., 2015).Erythrina indica is being used to make AgNPs that is spherical in form and has a size range of 20-118 nm.In addition, biologically generated Ag NPs showed strong antibacterial activity against Gram positive and Gram-negative bacteria, as well as a strong cytotoxic effect on breast and lung cancer cell lines (Rathi et al., 2015).In another study, Asparagus racemosus was shown to be useful in Indian traditional medicine for enhancing overall health and treating stress-related immunological diseases.In order to make 10-17 nm AgNPs, methanol and aqueous extracts of these plants' tuberous roots were used.However, the AgNPs showed antibacterial effect against E. coli, S. aureus, B. subtilis, K. pneumonia, P. fluorescence, A. hydrophila,E. tarda,F. branchiophilum,Y. ruckeri (Table 4).

From Fruits
A flowering plant's matured ovary, which contains the seeds and fruits, is mostly made up of carbohydrates, dietary fiber, enzymes, protein, fat, minerals, vitamins, phenolic acids and carotenoids.Fruit NPs have been demonstrated to exhibit antibacterial, catalytic, anticancer and antioxidant capabilities, among other biological activities.Carotenoids are plant pigments that give fruits their attractive red, yellow and orange hues; around 600 fruit carotenoids have been discovered thus far.Orange-colored foods, which are known for having the highest provitamin a activity, are the main source of -carotene.Flavonoids are phenolic compounds that comprise anthocyanins, flavanones, catechins, flavanols, flavones, and isoflavones.So far, almost 4000 fruit flavonoids have been found.The primary and secondary metabolites found in fruits are also retained.In the realm of green NPsproduction, plant fruit extract is commonly employed.There is numerous literature available on the green synthesis of AgNPs employing fruit extracts Helicteres lsora (Ramesh et al., 2015), Emblica nline at: le o b ila Ava -1415 -officinalis (Ramesh et al., 2015) and Solanum trilobatum (Ramar et al., 2015). S.aureus, B. subtilis, E. coli, K. pneumonia, S. mutans, B. cereus and S. typhi were effectively investigated using fruit extract for bio-genic NPs manufacturing.It has been shown that when the concentrations of the fruit extract increases, the size of the AgNPs reduces, and antibacterial activity increases (Masum, Siddiqa et al., 2019).Gnanajobitha et al., 2013 explained V. vinifera fruit-mediated synthesis of AgNPs of 30-40nm average mean sizes with spherical shape, also the inhibition zone was observed against B. subtilis and K. planticola.Aqueous silver nitrate was used to make AgNPs with Tamarindus indica fruit extract as a reducing and stabilizing agent.UV-VIS spectrophotometry was used to monitor the generation of AgNPs and XRD and FTIR were used to compute the mean particle diameter of silver NPs (Renuka et al., 2017).Various fruit extract used for the green synthesis of MNPs and their applications are listed in table 5.

From Gum
Gum is a sticky sap or other substance that is generally polysaccharide-based and is most commonly associated with woody plants, notably under the bark or as a seed covering.Plant gums are complex carbohydrate polymers that may additionally contain hydroxyproline-rich proteins, resins, or other components.They can be soluble, partially soluble or insoluble.Gum is secreted in response to insect or other herbivore damage and radiation damage.Also, plant resins have antimicrobial, antioxidant, antispasmodic, arrhythmia, especially tachycardic activities and used in traditional medicine.Gum extracts from a variety of plants have long been used as a bio-reducing and stabilizing agent in the green production of MNPs, as shown in table 6. Kora et al., 2012 employed gum ghatti (Anogeissus latifolia) as a reducing and stabilizing agent for 5.7 0.2 nm spherical AgNPs.They investigated the effects of gum concentration and reaction duration on NPs production.Alharbi et al. 2016 synthesized AuNPs with a spherical shape using Terminalia arjuna gum extract as a source of reducing and stabilizing compounds, with fabrication confirmed by UV-Vis, XRD and TEM and it was discovered that synthesize AuNPs significantly induced both mitotic division and pollen germination.An catalyst (GNiOc) for reduction of nitroarenes with sodium borohydride is being reported by Baranwalwt et al., 2018 synthesis of GNiOc was carried out by utilizing guar gum (GG) and the nanostructures have been characterized using UV-vis, FTIR, BET, XRD, SEM,TEM, TGA and DTA analysis.Similarly, the bactericidal activity of several more NPs from gum extract such as Salmaliamalabarica, (Murali Krishna et al., 2016) Styrax benzoin (Du et al., 2016) and Anacardium occidentale L. (Oliveira et al., 2019) displayed prominent cell damage against both Gram-positive and Gram-negative bacteria.

From Stem
The stem is the plant's stalk that rises above ground and has a variety of purposes, including support, conveying water, storing water, providing food, and aiding asexual reproduction.It also includes primary secondary metabolites and many functional groups.Particularly interesting are the carboxyl, amine, and phenolic compounds involved in the reduction of metal ions during NPsformation.Primary and secondary metabolites are constantly involved in the redox process in order to synthesize environmentally acceptable nanosized particles.Biosynthesized NPs have been proven in several studies to efficiently manage oxidative stress, genotoxicity and apoptosis-related changes.Methanolic extract of Callicarpa maingayi stems was used to manufacture AgNPs (Shameli et al. 2012).The conversion of silver ions to metallic AgNPs is aided by the aldehyde group in the plant extract.Amide I polypeptides, which play a role in the capping of ionic compounds into MtNPs, are denoted by the different functional groups -C=0, C=N (Shameli et al., 2012).Paulkumar et al. 2014 green manufacture AgNPs with diameters ranging from 7-50nm and 9-30nm from Piper nigrum leaves and stems, respectively, and investigate their antibacterial efficacy against agricultural plant diseases.As a reducing agent, Garcinia mangostana stem aqueous extract was used to make AgNPs.Surface plasmon resonance as evaluated by UV-visible spectra at 430nm verified the creation of AgNPs and morphology as determined by SEM, XRD, EDX, and UV-vis validated the reduction of silver ions to AgNPs with the aforesaid characteristics.Also, AgNP found effective against E. coli and B. subtilis bacterial strains (Karthiga, 2018).Dawodu et al. 2019 utilize Vigna unguiculata stem extract in preparation of 10-200nm AgNPs for remediation malachite green dye.Similarly, Kiran et al. 2020 prepare NiNPs by utilizing Citrullus colocynthis stem extract for remediation of Reactive Yellow 160 dye.Various stem extract used for the green synthesis of MNPs and their applications are listed in table 7.

From Bark
The outermost layers of stems and roots of woody plants are known as bark.The bark acts as a water barrier, keeping water inside the plant.Furthermore, many bioactive chemicals including as polyphenols, alkaloids, terpenoids, carbohydrates, proteins, saponins, and vitamins protect the deepest Available online at: https://jazindia.com-1416 -region of the stem.Many plants barks are used as spices and as medicine for their antioxidant properties, similarly bark based NPs also known for their medicinal properties.Yugandhar et al., 2015 prepare silver NPs using aromatic and spice plant Syzygium alternifolium, bark is utilized for synthesis of4-48nm spherical shaped NPs. S. alternifolium has antioxidant and anti-inflammatory activity, also used as anticancer medicine and very popular in tribals for ethical medicinal purpose.Similarly, Afzeliaquanzensis bark extract was used in the green production of AgNPs with diameters ranging from 10-80nm, and the generated AgNPs were found to have substantial antibacterial action against E. coli and S. aureus (Moyo et al., 2015).Furthermore, AgNPs mediated by Solanum trilobatum bark have been demonstrated to be compatible with good antibacterial properties (Ramanathan et al., 2018).Various bark extract used for the green synthesis of MNPs and their applications are listed in table 8.

From Rhizome
The rhizome is a subterranean stem that produces lateral branches and adventitious roots at regular intervals.Usually, rhizome is a modification of roots and is modified for food storage, at the same time it contains biological active compounds which promotes its medicinal properties.Curcuma longa is well known for its medicinal properties it contains a biological active compound named curcumin stored in its rhizomes, it also helps in reduction and stabilizing process during NPssynthesis and also provide NPs special properties because of its biological active compound.Hettiarachchi et al., 2021 prepared curcumin-based AgNPs and named it nanocucumin.The prepared 123.5nmZnO NPs were used to analysis of cytotoxicity (Kolahalam et al., 2021).Bergenia ciliata (BC) used for production of AgNPs is carried out using rhizomes, as evidenced by UV-vis, FTIR, SEM and other methods.Standard methods were used to test antibacterial and cytotoxic properties in vitro (Phull et al., 2016).Similarly, different rhizome extracts, such as Dryopteris crassirhizoma, were used to bio-synthesis spherical AgNPs (Lok et al., 2006).The synthesized AgNPs was utilized investigate antimicrobial activity against various bacterial strains and found excellent cell disruption of the bacteria.Various variety of LED light source such as red, blue, green light have been used toexamined bactericidal activity of NP.The zone of inhibition against B. cereus is greatest in green light mediated AgNPs, according to the scientists (Lok et al., 2006).Various rhizome extract used for the green synthesis of metal NPs and their applications are listed in table 9.

From Peels
Fruit and vegetable peels are considered agrowaste and are thrown into the environment instead of being used as a source of antimicrobial agents.Several researches on peels have revealed the presence of essential elements that can be utilized in pharmacological or medicinal applications.The use of peel extract as a reducing agent in the green production of nanoparticles has recently gained significant attention.Peel extract of Musa paradisiacal (Ibrahim, 2019),Carica papaya (Balavijayalakshmi et al., 2019) and Citrus sinensis (de Barros et al., 2018)were used for preparation of AgNPs, and also tested against various microbial strains to investigate its bactericidal activity and fungicidal activity and displayed great cell disruption.Similarly, Sengupta et al. 2012 used banana (Musa paradisiaca) to make 168.7nmAgNPs and investigated their antibacterial efficacy against E. coli, B.subtilis, S.aureus and Klebsiella sp., as well as dye degradation in wastewater.Various peel extract used for the green synthesis of MNPs and their applications are listed in table10.
From Bulb, Tuber, Latex, Pod Onion (Allium cepa) extract was recently employed as a reducing and capping agent in the biosynthesis of spherical AgNPs with diameters ranging from 10-23nm.The AgNPs exhibit good antibacterial action against B. subtilis, B. cereus, B. licheniformis, S. aureus, S. mutans, E. coli, K. pneumoniae, S. typhimurium, P. aeruginosa, P. vulgaris, S. marcescens and C. albicans, according to the authors (Gomaa, 2017).For the green synthesis of AgNPs, a variety of tube/bulb extracts were used, including Dioscoreaalata (Pugazhendhi et al., 2016) and Crocus haussknechtiiBois (Mosaviniya et al., 2019) as well as Gram-positive and Gram-negative bacterial strains were used to assess the NPs' bactericidal efficacy.Spherical AgNPs with diameters ranging from 10-25nm were generated using 20mM AgNO3, 0.5mL Crocus haussknechtiiBois extract at pH 7 and 75°C.Many more listed in table 11.

From Whole Plant
Plant extracts are used in the production of NPs, which is an important in nanobiotechnology.To date, there are several publications on the green synthesis of NPs employing entire plant extracts, herbs, and cryptogams such as bryophyte, pteridophyte whole plan is used, Sargassum muticum (Rajesh et al., 2014), Brassica oleracea L. (Kuppusamy et al., 2015), Sida acuta (Idrees et al., 2018)

Conclusion Future prospective of plant derived nanoparticles
Metal NPs biosynthesis utilizing plant derivatives has received a lot of attention in the recent two decades.Plant metabolites promote the environmentally beneficial creation of metallic NPs.The environmentally friendly synthesis of NPs utilizing plant crude extracts and purified metabolites might be potential substrates for large-scale manufacturing in the future.Plant-mediated NPs might be employed in a variety of industries, including medications, treatments, sustainable and renewable energy, and other commercial items.Plant-derived MNPs are expected to have a positive influence on the diagnosis and treatment of a variety of ailments; with minimal side effects.Plants have a bright future in the production of MNPs for use in healthcare and commercial applications.Despite the fact that there are two reasons to investigate in the biological generation of NPs: i.To determine which phytochemical substances (active metabolites) are partially or completely engaged in the reduction reaction?
ii. Laboratory-scale synthesis of MNPs to the point of large-scale manufacturing, as well as the necessity to understand their anti-pathogenic mechanism.

Fig 2 :Fig 3 :
Fig 2: Various steps of green synthesis of NPs.

Table 4 : Synthesis of NPs by Root
Harnessing Nature's Green Potential: Nanotechnology Driven Fabrication of Plant-Derived Nanoparticles Available online at: https://jazindia.com

Table 12 : Synthesis of NPs by Whole Plants
and many more listed in table 12.