Synthesis of Biocompatible Silver Nanoparticles and Nanotoxicity in Aquatic Ecosystems

MRS Advances ◽  
2020 ◽  
Vol 5 (16) ◽  
pp. 805-813
Author(s):  
Jousen A. Merced-Colón ◽  
David Medina-Suarez ◽  
Gabriela M. Mercado-Guzmán ◽  
Sonia J. Bailón
Keyword(s):  
Silver Nanoparticles ◽  
Aquatic Ecosystems ◽  
Negative Refraction ◽  
High Surface ◽  
Volume Ratio ◽  
Aquatic Organisms ◽  
Artemia Salina ◽  
Ag Nps ◽  
Spherical Form ◽  
Vis Spectroscopy

ABSTRACTSilver nanoparticles (Ag NPs) have unique optical, electrical, and thermal properties and are being incorporated into products that range from photovoltaics to biological and chemical sensors. The production of silver nanoparticles has been increasing worldwide in the nanotechnology industry due to the variety of applications and are very likely to reach aquatic ecosystems damaging them. Due to their small size and high surface area to volume ratio of NPs, they can strongly interact with life cells and cause damage to tested animals. Based on the mentioned previously, it is necessary to evaluate the silver nanoparticle nanotoxicity in aquatic ecosystems to prevent possible ingestion or transfer to humans. Also, the research will benefit aquatic systems due to less pollution around aquatic organisms. The objectives of this research included: i) production and characterization of stable silver nanoparticles in water, ii) characterizing the optical properties by UV-Vis spectroscopy and morphology by HR-TEM and; iii) evaluate the toxicity of silver nanoparticles in aquatic organisms, i.e Artemia salina. Results obtained evidenced that Ag NPs showed an intense absorption peak at 448 nm. This broad peak is due to the phenomenon called surface plasmon resonance (SPR) that is responsible for a variety of phenomena, including nanoscale optical focusing, negative refraction, and surface-enhanced Raman scattering. HR-TEM measurements evidenced the spherical form of the nanoparticles and its small size at around 12-20 nm. In addition, Electron Diffraction analyses suggested the composition of the nanoparticle, which contained only Ag0. The toxicity assays were evaluated using different concentrations of purified Ag NPs. During the cytotoxicity assay, it was demonstrated that Ag NPs were not toxic to Artemia salina after 24 and 48 hours of exposure. However, silver (as silver nitrate) evidenced high toxicity to Artemia salina at larval stage.

Biosynthesis of silver nanoparticles by natural precursor from clove and their antimicrobial activity

Biologia ◽  
2013 ◽  
Vol 68 (6) ◽  
Author(s):  
Harpreet Kaur ◽  
Simerjit Kaur ◽  
Minni Singh
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
High Surface ◽  
Scale Up ◽  
High Surface Area ◽  
Volume Ratio ◽  
Syzygium Aromaticum ◽  
Extracellular Biosynthesis ◽  
Vis Spectroscopy ◽  
Average Size

AbstractSilver nanoparticles (AgNPs) have attracted the attention of researchers because of their unique properties and applications in various fields, such as medicine, catalysis, textile engineering, and pollution treatment. The green synthesis of AgNPs has many advantages, such as less time requirement, highly stable AgNPs, better control over crystal growth, morphology, ease for scale up, and economic viability. Syzygium aromaticum (clove) was used for the extracellular biosynthesis of AgNPs. Eugenols are the active biomolecules present in clove, responsible for the bioreduction of AgNO3 (Ag+) leading to the formation and capping of AgNPs (Ag0). One molecule of eugenol releases two electrons and these two electrons will be taken by 2 Ag+ ions and these will get reduced to 2 Ag0. The synthesis of AgNPs was confirmed by the appearance of brown colour. The synthesized AgNPs were characterised by various techniques, such as UV-VIS spectroscopy, transmission electron microscopy, X-ray diffraction and Fourier transformed infrared spectroscopy. The synthesised AgNPs have λ max of 440 nm. It was evaluated that the AgNPs were biphasic in nature (cubic + hexagonal) with an average size of 50.0 nm. The synthesized AgNPs showed significant antimicrobial activity against Bacillus cereus NCDC 240 as they are nano-sized and have high surface area to volume ratio. AgNPs inhibit the growth of bacteria by various ways, such as by disrupting the cell membrane of bacteria, uncoupling the oxidative phosphorylation, inhibiting the DNA replication, forming free radicals and affecting the cellular signalling of bacteria leading to cell death.

scholarly journals Green synthesis of silver nanoparticles: Characterization and its potential biomedical applications

2021 ◽  
Vol 10 (1) ◽  
pp. 412-420
Author(s):  
Mona S. Alwhibi ◽  
Dina A. Soliman ◽  
Manal A. Awad ◽  
Asma B. Alangery ◽  
Horiah Al Dehaish ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Aloe Vera ◽  
Inhibition Zone ◽  
Biologically Active ◽  
Noble Metal Nanoparticles ◽  
Biological Synthesis ◽  
Ag Nps ◽  
Mouse Melanoma ◽  
Therapeutic Benefits ◽  
Vis Spectroscopy

Abstract In recent times, research on the synthesis of noble metal nanoparticles (NPs) has developed rapidly and attracted considerable attention. The use of plant extracts is the preferred mode for the biological synthesis of NPs due to the presence of biologically active constituents. Aloe vera is a plant endowed with therapeutic benefits especially in skincare due to its unique curative properties. The present study focused on an environmental friendly and rapid method of phytosynthesis of silver nanoparticles (Ag-NPs) using A. vera gel extract as a reductant. The synthesized Ag-NPs were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier transform infrared (FTIR), and dynamic light scattering (DLS). TEM micrographs showed spherical-shaped synthesized Ag-NPs with a diameter of 50–100 nm. The UV-Vis spectrum displayed a broad absorption peak of surface plasmon resonance (SPR) at 450 nm. The mean size and size distribution of the formed Ag-NPs were investigated using the DLS technique. Antibacterial studies revealed zones of inhibition by Ag-NPs of A. vera (9 and 7 mm) against Pseudomonas aeruginosa and Escherichia coli, respectively. Furthermore, the antifungal activity was screened, based on the diameter of the growth inhibition zone using the synthesized Ag-NPs for different fungal strains. Anticancer activity of the synthesized Ag-NPs against the mouse melanoma F10B16 cell line revealed 100% inhibition with Ag-NPs at a concentration of 100 µg mL−1. The phytosynthesized Ag-NPs demonstrated a marked antimicrobial activity and also exhibited a potent cytotoxic effect against mouse melanoma F10B16 cells. The key findings of this study indicate that synthesized Ag-NPs exhibit profound therapeutic activity and could be potentially ideal alternatives in medicinal applications.

scholarly journals Nanocatalytic Activity of Silver Nanoparticles (Ag-Nps) Fabricated using Camellia sinensis (Linn) Tender Leaf Extract and their Characterization

2020 ◽  
Vol 2 (1) ◽  
pp. 24
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pancreatic Enzyme ◽  
Alpha Amylase ◽  
Assay Method ◽  
Ag Nps ◽  
Visible Absorption ◽  
Biological Reduction ◽  
Vis Spectroscopy ◽  
Uv Visible

Silver nanoparticles (Ag-NPs) were prepared by the biological reduction method. Green tea extract was taken as a reducing and stabilizing agent and silver nitrate as the metal precursor for nanoparticle synthesis. The formation of the silver nanoparticles was monitored visually and using UV-Visible absorption spectroscopy. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, FTIR, Zeta sizer, Zeta potential, and antimicrobial studies. Silver nanoparticles were also subjected to investigate nanocatalytic activity with standard pancreatic alpha-amylase and bacterial amylase enzyme by the DNS assay method. UV-Vis spectroscopy revealed the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 430 nm. Four major functional groups of bio-molecules such as phenol, carboxylic acid, protein, and alkyl group were recorded in FTIR spectra. The size of the nanoparticles ranges between 5nm and 150nm. The average size and size distribution of silver nanoparticles is 59.66nm. The zeta potential of the silver nanoparticle is negatively charged and rendered as a sharp peak at -31.7mV. Antimicrobial activity of silver nanoparticles exhibited the highest inhibition against Gram-negative bacteria than Gram-positive bacteria and yeast pathogens. Starch hydrolysis of Ag-NPs was studied with pancreatic alpha-amylase (tailor made), crude and purified bacterial amylase enzyme. The formation of reducing sugar was increased about 40-fold for a purified enzyme, 11-fold for the pancreatic enzyme, and 6-fold for crude bacterial enzyme incorporated with Ag-NPs over control. The present studies recommended that Ag-NPs have a significant role in the degradation of starch into reducing sugars by acting as a nanocatalyst.

scholarly journals Microwave-Assisted Green Synthesis of Silver Nanoparticles Using Juglans regia Leaf Extract and Evaluation of Their Physico-Chemical and Antibacterial Properties

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Mahsa Eshghi ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Mohammad Najian ◽  
Hoda Jafarizadeh-Malmiri ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Juglans Regia ◽  
Antibacterial Properties ◽  
Infrared Analysis ◽  
Ag Nps ◽  
Stabilizing Agents ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.

scholarly journals Biogenic silver nanoparticles from Trichodesma indicum aqueous leaf extract against Mythimna separata and evaluation of its larvicidal efficacy

2017 ◽  
Vol 57 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Abdul A. Buhroo ◽  
Gousul Nisa ◽  
Syed Asrafuzzaman ◽  
Ram Prasad ◽  
Razia Rasheed ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Average Particle ◽  
Particle Sizes ◽  
Mythimna Separata ◽  
Ag Nps ◽  
Leaf Extracts ◽  
Tem Analysis ◽  
Vis Spectroscopy ◽  
Aqueous Leaf Extract

AbstractThe present exploration is focused on the bio-fabrication of silver nanoparticles (Ag NPs) usingTrichodesma indicumaqueous leaf extract as a reducing agent. The synthesized Ag NPs were productively characterized by UV-vis spectroscopy, XRD, and TEM studies. The photosynthesis of Ag NPs was done at room temperature for 24 h and at 60°C. The green synthesis of spherical-shaped Ag NPs bio-fabricated fromT. indicumwith a face centred cubic structure showed average particle sizes of 20–50 nm, which is inconsistent with the particle size calculated by the XRD Scherer equation and TEM analysis. We further explored the larvicidal efficacy of biosynthesized Ag NPs with leaf extracts ofT. indicumagainstMythimna separata. The results showed that Ag NPs (20–50 nm) ofT. indicumpossess good larvicidal activity againstM. separatawith an LC50of 500 ppm. Thus, we can advocate that Ag NPs of 20–50 nm size extracted fromT. indicummay be considered in the pest management programme ofM. separatain future.

scholarly journals Green Synthesis of Silver Nanoparticles in the Presence of Polysaccharide: Optimization and Characterization

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Margarita I. Skiba ◽  
Victoria I. Vorobyova ◽  
Alexander Pivovarov ◽  
Natalya P. Makarshenko
Keyword(s):  
Silver Nanoparticles ◽  
Sodium Alginate ◽  
Xrd Analysis ◽  
Face Centered Cubic ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Sem Images ◽  
Spherical Powder ◽  
Stabilizing Agent ◽  
Vis Spectroscopy

The process of obtaining aqueous solutions of silver nanoparticles with the use of a low-temperature nonequilibrium contact plasma and stabilizing agent—polysaccharide (sodium alginate)—has been examined. The synthesized Ag NPs were characterized by using UV-Vis spectroscopy, dynamic light scattering (DLS), scanning electron microscope (SEM), and XRD analysis. The effect of concentration of Ag+, sodium alginate, duration of processing by plasma discharge, and pH of liquid on the production of silver nanoparticles has been studied. The results demonstrated that synthesis provides the formation of silver nanoparticles for investigated concentrations of Ag+ (0.3-3.0 mmol/l) and 5.0 g/l Na-Alg (pH=7–10) within 1–5 minutes. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles have a face-centered cubic crystal structure. Zeta potential of plasma-chemically obtained colloidal solutions at various concentrations of Ag+ ions and stabilizing agent varies from −32.8 to −39.3 mV, indicating the moderate stability of synthesized nanoparticles.

scholarly journals Silver Nanoparticles: Biosynthesis Using an ATCC Reference Strain ofPseudomonas aeruginosaand Activity as Broad Spectrum Clinical Antibacterial Agents

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Melisa A. Quinteros ◽  
Ivana M. Aiassa Martínez ◽  
Pablo R. Dalmasso ◽  
Paulina L. Páez
Keyword(s):  
Silver Nanoparticles ◽  
Broad Spectrum ◽  
Nitrate Solution ◽  
Human Neutrophils ◽  
Resistant Bacteria ◽  
Klebsiella Pneumonia ◽  
Bacterial Strains ◽  
Ag Nps ◽  
Tem Analysis ◽  
Vis Spectroscopy

Currently, the biosynthesis of silver-based nanomaterials attracts enormous attention owing to the documented antimicrobial properties of these ones. This study reports the extracellular biosynthesis of silver nanoparticles (Ag-NPs) using aPseudomonas aeruginosastrain from a reference culture collection. A greenish culture supernatant ofP. aeruginosaincubated at 37°C with a silver nitrate solution for 24 h changed to a yellowish brown color, indicating the formation of Ag-NPs, which was confirmed by UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. TEM analysis showed spherical and pseudospherical nanoparticles with a distributed size mainly between 25 and 45 nm, and the XRD pattern revealed the crystalline nature of Ag-NPs. Also it provides an evaluation of the antimicrobial activity of the biosynthesized Ag-NPs against human pathogenic and opportunistic microorganisms, namely,Staphylococcus aureus,Staphylococcus epidermidis,Enterococcus faecalis,Proteus mirabilis,Acinetobacter baumannii,Escherichia coli,P. aeruginosa, andKlebsiella pneumonia. Ag-NPs were found to be bioactive at picomolar concentration levels showing bactericidal effects against both Gram-positive and Gram-negative bacterial strains. This work demonstrates the first helpful use of biosynthesized Ag-NPs as broad spectrum bactericidal agents for clinical strains of pathogenic multidrug-resistant bacteria such as methicillin-resistantS. aureus,A. baumannii, andE. coli. In addition, these Ag-NPs showed negligible cytotoxic effect in human neutrophils suggesting low toxicity to the host.

Cascade catalysis of highly active bimetallic Au/Pd nanoclusters: structure–function relationship investigation using anomalous small-angle X-ray scattering and UV–Vis spectroscopy

2013 ◽  
Vol 46 (5) ◽  
pp. 1353-1360 ◽  
Author(s):  
Sylvio Haas ◽  
Robert Fenger ◽  
Edoardo Fertitta ◽  
Klaus Rademann
Keyword(s):  
Catalytic Activity ◽  
Structural Characteristics ◽  
High Surface ◽  
Volume Ratio ◽  
Single Type ◽  
High Catalytic Activity ◽  
Highly Active ◽  
Bimetallic Nanoclusters ◽  
Vis Spectroscopy ◽  
Cascade Catalysis

Recently, a so-called `crown-jewel' concept of preparation of Au/Pd-based colloidal nanoclusters has been reported [Zhang, Watanabe, Okumura, Haruta & Toshima (2011).Nat. Mater.11, 49–52]. Here, a different way of preparing highly active Au/Pd-based nanoclusters is presented. The origin of the increased activity of Au/Pd-based colloidal bimetallic nanoclusters was unclear up to now. However, it is, in general, accepted that in the nanometre range (1–100 nm) the cluster size, shape and composition affect the structural characteristics (e.g.lattice symmetry, unit cell), electronic properties (e.g.band gap) and chemical properties (e.g.catalytic activity) of a material. Hence, a detailed study of the relationship between the nanostructure of nanoclusters and their catalytic activity is presented here. The results indicate that a high surface-to-volume ratio of the nanoclusters combined with the presence of `both' Au and Pd isolated regions at the surface are crucial to achieve a high catalytic activity. A detailed structure elucidation directly leads to a mechanistic proposal, which indeed explains the higher catalytic activity of Au/Pd-based catalysts compared with pure metallic Au or Pd. The mechanism is based on cascade catalysis induced by a single type of nanoparticle with an intermixed surface of Au and Pd.

scholarly journals Photocatalytic Activity of Revolutionary Galaxaura elongata, Turbinaria ornata, and Enteromorpha flexuosa’s Bio-Capped Silver Nanoparticles for Industrial Wastewater Treatment

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3241
Author(s):  
Manal N. Abdel Azeem ◽  
Safwat Hassaballa ◽  
Osama M. Ahmed ◽  
Khaled N. M. Elsayed ◽  
Mohamed Shaban
Keyword(s):  
Silver Nanoparticles ◽  
Wastewater Treatment ◽  
Organic Dyes ◽  
Exposure Period ◽  
Marine Macroalgae ◽  
Ag Nps ◽  
Turbinaria Ornata ◽  
Vis Spectroscopy ◽  
Safranine O ◽  
The Impact

More suitable wastewater treatment schemes need to be developed to get rid of harmful dyes and pigments before they are discharged, primarily from apparel and textile factories, into water bodies. Silver nanoparticles (Ag-NPs) are very effective, reductive nanocatalysts that can degrade many organic dyes. In this study, Ag-NPs are stabilized and capped with bioactive compounds such as Galaxaura elongata, Turbinaria ornata, and Enteromorpha flexuosa from marine macroalgae extracts to produce Ag[GE], Ag[TE], and Ag[EE] NPs. The reduction of Ag ions and the production of Ag[GE], Ag[TE], and Ag[EE] NPs have been substantiated by UV–Vis spectroscopy, SEM, EDX, and XRD tests. The NPs are sphere and crystalline shaped in nature with dimensions ranging from 20 to 25 nm. The biosynthesized Ag[GE], Ag[TE], Ag[EE] NPs were applied to photodegrade hazardous pigments such as methylene blue, Congo red, safranine O, and crystal violet under sunlight irradiation. In addition to the stability analysis, various experimental parameters, including dye concentration, exposure period, photocatalyst dose, and temperature, were optimized to achieve 100% photodegradation of the dyes. Moreover, the thermodynamic and kinetic parameters were calculated and the impact of scavengers on the photocatalytic mechanism was also investigated.

scholarly journals Diatom Mediated Production of Fluorescent Flower Shaped Silver-Silica Nanohybrid

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7284
Author(s):  
Piya Roychoudhury ◽  
Aleksandra Golubeva ◽  
Przemysław Dąbek ◽  
Michał Gloc ◽  
Renata Dobrucka ◽  
...  
Keyword(s):  
High Surface ◽  
Nitrate Solution ◽  
Volume Ratio ◽  
Cost Effective ◽  
Silver Nitrate Solution ◽  
Hybrid Nanoparticles ◽  
Sem Images ◽  
Light Region ◽  
Vis Spectroscopy ◽  
Sio2 Particles

Fabrication of flower-like nanostructures are gaining attention because of their high surface/volume ratio and extensive adsorption capacity. In the present investigation, flower-shaped, autofluorescent silver-silica (Ag-SiO2) hybrid nanoparticles have been fabricated exploiting diatoms as a source of nanosilica. Two different species of Gedaniella including G. flavovirens and G. mutabilis showed their efficacy in synthesizing fluorescent Ag-SiO2 nanoflowers (NFs) and nanospheres (NSs) against 9 mM silver nitrate solution, respectively. The biogenic nanoconjugate (Ag-SiO2) was characterized by Uv-vis spectroscopy, energy dispersive X-ray spectroscopy (EDS), scanning (SEM) and transmission (TEM) electron microscopy. Production of Ag-SiO2 hybrid nanoparticle was confirmed by observing both Ag and Si signals from a single nanoparticle in an EDS study. The broad and single absorption band at ~420 nm in Uv-vis spectroscopy confirmed proper miscibility and production of hybrid nanoparticles. The Ag-SiO2 nanohybrids revealed autofluorescent property under the blue light region (excitation ~450–490 nm). SEM images of particles synthesized by G. flavovirens revealed the production of microscopic flower shaped Ag-SiO2 particles with several layers of petals. A TEM study confirmed that the synthesized Ag-SiO2 NFs are variable in size with 100–500 nm in diameter. Decolorization of methylene blue after exposure to Ag-SiO2 particles confirmed catalytic activity of synthesized nanostructures. This eco-friendly method provides a new dimension in nanobiotechnology for biogenesis of such hierarchical nanostructure in a cost-effective way.

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