Nanotechnology is the field of study of materials at nanoscale. It involves the production, manipulation, and use of materials ranging in size from less than one micron to that of individual atoms from not only chemical approaches but also biological materials. Silver, Copper and Zinc nanoparticles were successfully synthesised from Silver nitrate, Copper sulphate and Zinc sulphate respectively through a simple green and natural route using latex of 5 different plant taxa. Nanoparticle formation was proved by UV-vis spectroscopy. The antimicrobial well diffusion method used was give information about the antibacterial activity of latex nanoparticles towards 5 different bacterial species by measuring the zone of inhibition. The use of two dilutions of latex solution was used for the comparative study of zone of inhibition. As nanoparticles have great application in medical world like gene therapy, cancer therapy, drug delivery, etc. So medical world also accept the plant world for nanoparticle synthesis and mainly welcome the angiosperms for their potentiality of synthesis of non-polluted, environmentally acceptable, safety for human health nanoparticles.

Nanotechnology is an emerging field of science. It has increased applications in diverse area for the development of new materials at nanoscale levels. Synthesis of nanoparticles using biological methods is referred as greener synthesis of nanoparticles. Seed extracts of papaya (Carica papaya), Mullatha (Annona muricata), Passion fruit (Passiflora edulis), Eenth (Cycas circinalis), Egg fruit (Pouteria campechiana) are used for the synthesis of silver, copper, and zinc nanoparticles. These plants have medicinal as well as antibacterial activity. Nanoparticles prepared from these seed extracts have antibacterial activity. Synthesized nanoparticles were characterized by UV-VIS Spectrophotometry. Silver nanoparticles shows maximum peak at 385 nm. Copper nanoparticles shows maximum peak at 680 nm. Zinc nanoparticles shows maximum peak at 350 nm. Synthesized silver, copper and zinc nanoparticles shows antibacterial activity against Salmonella species, Pseudomonas species, Staphylococcus species, E. coli and Klebsiella species. Antimicrobial assay was performed by agar well diffusion method using Muller Hinton agar media. when antibacterial activity of silver, copper and zinc nanoparticles from 3 different concentrations were observed, nanoparticles have 60 µl concentration shows maximum activity against these microbes. Silver nanoparticles shows greater antibacterial activity compared to silver nitrate and seed extract. Copper nanoparticles shows greater antibacterial activity compared to copper Sulphate and seed extract. Zinc nanoparticles shows greater antibacterial activity compared to zinc Sulphate and seed extract. Maximum zone of inhibition was at 60 µl for all the bacterial cultures. This green synthesis method is alternative to chemical method, since it is cheap, pollutant free and eco-friendly.

Nanoparticles are particles with dimension on the range 10-9 and 10-10. Green synthesis is the new method developed for the synthesis of nanoparticles which is small in size, large surface area and eco-friendly. In India plant and tree leafs are used as medicine for the treatment of various diseases. They are rich source of antimicrobial agents. Silver, copper and zinc nanoparticles are synthesised from the leaf extract of different plants. Leaf extracts of Glycosmis pentaphylla (Pannal), Macaranga peltata (Vatta), Emilia sonchifolia (Muyal cheviyan), Tabernaemontana divericata (Nandhiar vattam) and Clerodendrum infortunatum (Peravam) are used for the synthesis of nanoparticles. Leaf extract is added to the prepared stock solution of1mM silver nitrate, 100mM copper sulphate and100mM zinc sulphate. Synthesised nanoparticles were characterized by UV-VIS spectrophotometry to confirm the formation of nanoparticles. Anti-bacterial are used to treats bacterial infections. The leaf extract and silver nitrate, copper sulphate, zinc sulphate has antibacterial activity. The antibacterial activity of synthesised nanoparticle is determined using agar well diffusion method. The synthesised nanoparticles exhibit anti- bacterial activity by inhibiting the growth of gram negative and gram positive bacteria.

Soil borne diseases which are caused to various plants include a wide variety of soil microbes like fungi and bacteria, among which Fusarium wilt is one such disease caused by Fusarium oxysporum cubense in banana plants. Wilt disease or the panama disease of plant is among the most destructive disease of banana in the tropics and even the control methods like field sanitation, soil treatments and crop rotations have not been a long term control for this disease. An alternative method of treating Fusarium oxysporum was adopted by using various banana parts mainly its peel, pulp sap and its latex of varieties such as Robusta (B1) Musa acuminate Colla (AAA), Etha (B2) Musa x paradisiaca (AAB), Poovan (B3) Musa x paradisiaca (AAB), Sundari (B4) Musa acuminate Colla (AA), Njalipoovan (B5) Musa acuminate Colla (AB), Palayamkodan (B6) Musa x paradisiaca (AAB), Kannan (B8) Musa acuminate Colla (AAA), Pachakadali (B9) Musa acuminate Colla (AAA). Nanoparticles are small particles with a dimension of 10-9 and 10-10. Green synthesis is a new method developed for the synthesis of nanoparticles which is small in size, large surface area and eco- friendly. Leaf extracts of these plants were used for synthesis of copper and zinc nanoparticles, as nanoparticles are powerful antimicrobial agents. The results shows that dry skin and fruit extracts of Palemkodan, Njalipoovan, Etha, Pachakhadali with solvents, propane, ethanol, methanol and acetone and the fresh extract latex and sap of Palemkodan and Poovan with solvents isoproponol, ethanol, methanol with 1/10 and 1/50 dilution are used for the synthesis of copper and zinc nanoparticles. Copper and zinc nanoparticle shows greater antifungal activity than copper sulphate and zinc sulphate, respectively and dry extract. The maximum zone of inhibition was at 50 and 100 µl for all the test plates. This indicates that the zone of inhibition increases with as the concentration of nanoparticles increased. An overall result showed that ethanol, methanol and isoropane could be used as a good solvents and skin of Njalipoovan and Etha could be used for controlling the Fusarium oxysporum cubense under invitro conditions.

Soil borne diseases which are caused to various plants include a wide variety of soil microbes like fungi and bacteria, among which Fusarium wilt is one such disease caused by Fusarium oxysporum cubense in banana plants. Wilt disease or the panama disease of plant is among the most destructive disease of banana in the tropics and even the control methods like field sanitation, soil treatments and crop rotations have not been a long term control for this disease. An alternative method of treating Fusarium oxysporum was adopted by using various natural plant leaves of Chromolaena odorata, Justicia adhatoda, Glycosmis pentaphylla, Azadirachta indica, Gliricidia sepium, Piper nigrum, Ocimum tenuiflorum and Tabernaemontana divaricate. Nanoparticles are small particles with a dimension of 10-9 and 10-10. Green synthesis is a new method developed for the synthesis of nanoparticles which is small in size, large surface area and eco- friendly. Leaf extracts of these plants were used for synthesis of copper and zinc nanoparticles, as nanoparticles are powerful antimicrobial agents. The extract is prepared with a stock solution of 100mM copper sulphate and 100mM zinc sulphate. The leaf extracts were prepared with 5 solvents (Distilled water, Propane, Hexane, Acetone and Methanol). The action of plant leaves were observed by the zone of inhibition obtained with a concentration of 50, 100 and 150µl respectively. The result was more in copper nanoparticles of leaf extract as compared to the zinc nanoparticles of particular leaf extracts but the zinc particles with methanol and propane showed good result with particular leaves. In dried condition of leaves copper nanoparticles with propane as solvent exhibited a greater zone of inhibition. Moreover the solvent, methanol showed good results with both zinc and copper nanoparticles. The synthesized nanoparticle were characterized by UV-VIS spectrophotometry to confirm the formation of nanoparticles. Green synthesis is used namely because of low cost, simple, use of less toxic materials, most important is eco-friendly.