A review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications: A green expertise.

Synthesis of metallic nanoparticles using plant extracts.

Green synthesis of silver nanoparticles using Azadirachta indica aqueous leaf extract

Plant extract mediated synthesis of silver and gold nanoparticles and its antibacterial activity against clinically isolated pathogens.

Silver, known in metallic form since antiquity, has very early been recognized by mankind for its antimicrobial properties, a phenomenon observed, for example, in the context of drinking water (a silver coin in a well), food (silver cutlery, water storage recipients), and medicine (silver skull plates, teeth). Silver compounds were also shown to be useful. For example, dilute solutions of silver nitrate served long, and still do in some countries, as antimicrobial ointment to be instilled into Published in \" \" which should be cited to refer to this work.

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Nanobio Silver: Its Interactions with Peptides and Bacteria, and Its Uses in Medicine

Synthesis of antimicrobial silver nanoparticles by callus and leaf extracts from saltmarsh plant, Sesuvium portulacastrum L.

The present study investigated the extracellular biosynthesis of antimicrobial silver nanoparticles by Escherichia coli AUCAS 112 and Aspergillus niger AUCAS 237 derived from coastal mangrove sediment of southeast India. Both microbial species were able to produce silver nanoparticles, as confirmed by X-ray diffraction spectrum. The nanoparticles synthesized were mostly spherical, ranging in size from 5 to 20 nm for E. coli and from 5 to 35 nm for A. niger, as evident by transmission electron microscopy. Fourier transform spectroscopy revealed prominent peaks corresponding to amides I and II, indicating the presence of a protein for stabilizing the nanoparticles. Electrophoretic analysis revealed the presence of a prominent protein band with a molecular mass of 45 kDa for E. coli and 70 kDa for A. niger. The silver nanoparticles inhibited certain clinical pathogens, with antibacterial activity being more distinct than antifungal activity. The antimicrobial activity of E. coli was more pronounced than that of A. niger and was enhanced with the addition of polyvinyl alcohol as a stabilizing agent. This work highlighted the possibility of using microbes of coastal origin for synthesis of antimicrobial silver nanoparticles.

Analysis of antimicrobial silver nanoparticles synthesized by coastal strains of Escherichia coli and Aspergillus niger.

The present work investigated the effect of leaf extract from coastal plant Prosopis chilensis on synthesis of silver nanoparticles using AgNO3 as a substrate and to find their antibacterial potential on pathogenic Vibrio species in the shrimp, Penaeus monodon. The leaf extract could be able to produce silver nanoparticles, as evident by gradual change in colour of the reaction mixture consisted of the extract and 1 mM AgNO3 to dark brown. The silver nanoparticles exhibited 2θ values corresponding to the presence of silver nanocrystal, as evident by X-ray diffraction spectrum. The peaks corresponding to flavanones and terpenoids were found to be stabilizing agents of the nanoparticles, as revealed by Fourier transform infrared spectroscopy. The size of silver nanoparticles ranged from 5 to 25 nm with an average of 11.3 ± 2.1 nm and was mostly of spherical in shape, as confirmed by transmission electron microscopy. The silver nanoparticles were found to inhibit Vibrio pathogens viz., Vibrio cholerae, V. harveyi, and V. parahaemolyticus and this antibacterial effect was better than that of leaf extract, as proved by disc diffusion assay. The nanoparticles were then tested in the shrimp Penaeus monodon challenged with the four species of Vibrio pathogens for 30 days. The shrimps fed with silver nanoparticles exhibited higher survival, associated with immunomodulation in terms of higher haemocyte counts, phenoloxidase and antibacterial activities of haemolymph of P. monodon which is on par with that of control. Thus, the present study proved the possibility of using silver nanoparticles produced by coastal Prosopis chilensis as antibacterial agent in controlling vibriosis.

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Synthesis of silver nanoparticles by coastal plant Prosopis chilensis (L.) and their efficacy in controlling vibriosis in shrimp Penaeus monodon

A total of 13 leaf extracts of coastal plants were used for the synthesis of silver nanoparticles and to test the antimicrobial potential of nanoparticles. The highest amount of nanoparticles was obtained by Sesuvium portulacastrum followed by Prosopis chilensis, Hibiscus rosasinensis and Clerodendrum inerme. The synthesised nanoparticles were spherical with variable size ranging from 5 to 20 nm, as evident by transmission electron microscopy. The synthesis of silver nanoparticles was confirmed with X-ray diffraction spectrum. Fourier transform infrared spectroscopy identified the presence of amide I, II and III, aromatic rings, geminal methyls and ether linkages indicating the presence of biomolecules responsible for stabilisation of the silver nanoparticles. Protein bands with molecular weight in a range of 35 to 100 kDa were detected. The nanoparticles inhibited clinical strains of bacteria and fungi with more distinct antifungal activity, which was enhanced when polyvinyl alcohol was added as a stabilising agent.

In vitro synthesis of antimicrobial silver nanoparticles by mangroves, saltmarshes and plants of coastal origin

The present study investigated the synthesis of gold nanoparticles (AuNPs) using mangrove plant extract from Avicennia marina as bioreductant for eco-friendly bioremediation of 4-nitrophenol (4-NP). The AuNPs synthesised were confirmed by UV spectrum, transmission electron microscopy (TEM), X-ray diffraction, Fourier transmission infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential. The AuNPs were found to be spherical in shape with size ranging from 4 to 13 nm, as evident by TEM and DLS. Further, the AuNPs were encapsulated with sodium alginate in the form of gold nano beads and used as heterogeneous catalyst and degrading agent to reduce 4-NP. This reduction in 4-NP into 4-aminophenol was confirmed by UV and FTIR. The aqueous solution of 4-NP peaked its absorbance at 320 nm, and shifted to 400 nm, with an intense yellow colour, appeared due to formation of 4-nitrophenolate ion. After the addition of AuNps, the 4-NP solution became colourless and peaked at 400 nm and reduced to 290 nm corresponding to the formation of 4-aminophenol. Hence, the present work suggested the AuNPs as the potent, eco-friendly bionanocomposite catalyst for bioremediation of 4-NP.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-nbt.2017.0210

Asmathunisha Nabikhan

Papers

Synthesis of antimicrobial silver nanoparticles by callus and leaf extracts from saltmarsh plant, Sesuvium portulacastrum L.

Analysis of antimicrobial silver nanoparticles synthesized by coastal strains of Escherichia coli and Aspergillus niger.

Synthesis of silver nanoparticles by coastal plant Prosopis chilensis (L.) and their efficacy in controlling vibriosis in shrimp Penaeus monodon

In vitro synthesis of antimicrobial silver nanoparticles by mangroves, saltmarshes and plants of coastal origin

Biogenic gold nanoparticles for reduction of 4-nitrophenol to 4-aminophenol: an eco-friendly bioremediation