Search

The impressive role of silver nanoparticles (AgNPs) is well identified for cancer therapy. However, safety concerns have been raised about the adverse effects of high-doses of chemically-synthesized-AgNPs that release many hazardous residues and in turn diminish the anticancer property of AgNPs. Hence, to overcome these side effects and to maintain the anticancer effectiveness of AgNPs at relatively low-doses, the present study utilizes a natural antitumor product Ferula asafoetida (FA) in the preparation of green synthesis of AgNPs and further focuses on its cytotoxic effects, against Lung and Cervical cancer cells. The successful green-synthesis of FA-AgNPs was confirmed via UV–Vis-spectroscopy, TEM, DLS, FTIR and IR. Based on cytotoxicity assay, the average low (6.25 µl) and high (25 µl) doses of FA-AgNPs were observed to cause severe cytotoxic effects on studied cancer cells. Furthermore, our study was also directed to check any possible antitumorigenic-modulatory-effects of low and high doses of FA-AgNPs on the expression of four oncogenes (PIK3CA, KRAS, EGFR and ERBB3). In RT-qPCR analysis, the low and high doses of FA-AgNPs caused significant(p < 0.01) downregulation effects on the expression of PIK3CA and KRAS oncogenes, in treated-cancer cells. This is the first-report on the role of FA-AgNPs that induce strong cytotoxicity with its low-doses. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles were synthesized by a novel, environmentally friendly method using low-pressure cold plasma in different ways: for chemical and green synthesis. The "traditional" Ag NP capping agents (sodium citrate, sodium alginate, poly(vinyl alcohol), polyvinylpyrrolidone, Tween-80, sodium carboxymethyl cellulose, and "green" stabilizers (grape and orange pomace) were used in the researched synthesis methods. The synthesized Ag NPs were characterized through different techniques such as UV–Vis, DLS-method, SEM HR-TEM for morphology parameter investigation. It was established that the manifestation of antiradical activity (DPPH method) (30–80% in concentrations of 0.1–1.5 mg/mL) is ensured only when using "green" types of stabilizers, and in this case, the method of synthesis and characteristics of NPs are not of decisive importance. Experimental data and theoretical quantum-chemical calculations have shown that the intensity of the antiradical effect of "green" stabilizers (grape and orange pomace) is largely determined by the content of phenolic and polyphenolic compounds (LC–MS method). The type of stabilizer, which determines the size of the NPs and the zeta potential, has a decisive influence on the intensity of the manifestation of antimicrobial properties. The latter determines the rate of release of silver ions and the intensity of antimicrobial action. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been widely studied due to their interesting physicochemical properties and remarkable antibacterial properties. Chemical synthesis methods, including green chemistry, have achieved 0D nanostructures. However, ecological methods have little studied self-assembling Ag nanostructures, such as flowers or dendrites. In this work, Ag dendrites and Ag flower-like morphologies have been successfully synthesized using a one-step green method employing Arctostaphylos pungens Kunth fruit extract at room temperature. The antibacterial properties of both nanostructures were evaluated against Gram-positive Escherichia coli and Gram-negative Staphylococcus aureus bacteria. Scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), and infrared spectroscopy (IR) characterized the synthesized products. The morphological changes of the nanostructures come from the variation in the concentration of the precursor salt, silver nitrate (AgNO3). A growth mechanism is proposed that includes the formation of nanospheres and their subsequent transformation into Ag dendrites. Both nanostructures show good antibacterial activity against the tested microorganisms. The Ag dendritic nanostructures presented inhibition zones of 11 mm and 10.7 mm against Escherichia coli and Staphylococcus aureus bacteria. However, the flower-like structure was slightly less effective, presenting 11 and 9.5 mm inhibition zones against the same microorganisms, respectively. [ABSTRACT FROM AUTHOR]

Pollution of water by leaking industrial dyes has become a major problem for aquatic organisms and human-being. Polluted water treatment methods need efficient alternatives to conventional dye removing techniques. In this study, the catalytic activity of cellulose based silver nanocomposite against the pollutant methylene blue dye was searched. Cellulose based silver nanocomposite was synthesized by using in situ green synthesis method with Laurus nobilis extract. UV–VIS, FTIR, SEM, TEM, EDS, XRD, BET analyses were used to characterization of synthesized nanocomposite. Electron microscopy results confirmed that 25 nm diameter silver nanoparticles were supporting the 25 nm width cellulose nanofibers. Elemental composition of confirmed by UV–VIS, FTIR, XRD and EDS results which including silver and cellulose specific peaks. BET results showed that nanocomposite have 11.1 nm pore size with 199,8508 m2/g specific surface area. Catalytic activity of nanocomposite was performed against methylene blue in the presence of NaBH4. Catalytic activity was traced for up to 120 min and complete removal of methylene blue dye was estimated as 1 h. Moreover, the recycled nanocomposite was found reusable without activity loss for three times. These results offer an easy, eco-friendly and reusable dye removing material for wastewaters which were polluted by industrial dyes. [ABSTRACT FROM AUTHOR]

Gastric cancer is a major human health threat and finding novel and effective anticancer compounds against it is crucially important. Silver nanoparticles (NPs) have promising anticancer potential with minimal side effects. Functionalization of Ag NPs with magnetic compounds could provide novel features, including targeted drug delivery and photothermal therapy. In this work, green synthesis and characterization of MgFe2O4@Ag nanocomposite were performed. The anticancer potential of the nanocomposite against adenocarcinoma gastric (AGS) cells was investigated using MTT, flow cytometry, Hoechst staining, and caspase-3 activation assays. Also, the relative expression of the Bax and Bcl-2 genes in nanocomposite treated cells was investigated. Proper synthesis and crystallinity of the MgFe2O4@Ag NPs were confirmed by the Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. Scanning and transmission electron microscopy indicated the spherical shape of the NPs with the size range of 23–53 nm. Lack of elemental impurities and good stability of the NPs was confirmed by energy dispersive X-ray (EDX) mapping and measuring zeta potential (− 35.5 mv), respectively. The MgFe2O4@Ag NPs showed a significantly higher antiproliferative potential against AGS cells (IC50 = 43 µg/mL), than human embryonic kidney cells (HEK293) cells (IC50 = 158 µg/mL). Moreover, flow cytometry and Hoechst staining confirmed apoptosis induction in treated AGS cells. Also, the activity of the caspase-3 protein and expression of the Bax gene among MgFe2O4@Ag treated cells was significantly increased to 1.8 and 1.21 folds, respectively, while the Bcl-2 gene was down-regulated to 0.68 folds. This study revealed the promising anticancer potential of MgFe2O4@Ag NPs to be used for gastric cancer treatment after further characterization using in-vitro and in-vivo assays. [ABSTRACT FROM AUTHOR]

In order to investigate the physicochemical properties and bioactivities of AgNPs prepared using green and chemical approaches and further explore the related antibacterial mechanism, one kind of chemical AgNPs (C-AgNPs) and three kinds of green AgNPs (G-AgNPs) mediated with aqueous extracts of Morus alba L. were prepared and characterized. All G-AgNPs displayed higher antioxidant activities in DPPH radical scavenging, reducing power and total antioxidant assays than C-AgNPs and extracts. Meanwhile, all G-AgNPs exerted significantly (P < 0.05) enhanced antimicrobial activities against various pathogens compared with C-AgNPs and extracts. Among prepared AgNPs, ML-AgNPs mediated with aqueous extract of Morus alba L. leaves exhibited the most powerful antibacterial effect with the largest inhibition zones (13.11 ± 0.76 mm for S. aureus, 13.27 ± 0.22 mm for E. coli) and the lowest minimum inhibition concentrations against S. aureus (6.125 μg/ml) and E. coli (3.125 μg/ml). ML-AgNPs could inhibit the growths of S. aureus and E. coli in time- and dose-dependent modes, and even could disrupt the bacterial structure integrality resulting in the leakage of intracellular contents. G-AgNPs, especially ML-AgNPs, with remarkable bioactivities could replace C-AgNPs as related agents applied in agriculture and medicine. [ABSTRACT FROM AUTHOR]

Delonix regia has bioactive phytochemicals present in leaves, seeds, roots, and flowers. Considering that these compounds are common in extracts used for silver nanoparticles (AgNPs) biosynthesis, this study investigated the potential of D. regia seeds aqueous extract (DRE) in different concentrations to produce AgNPs (DRE-AgNPs). DRE composition was investigated by qualitative assays, and physico-chemical/structural characterization of AgNPs was performed by UV–Visible spectroscopy, dynamic light scattering (DLS), Zeta potential, and atomic force microscopy (AFM). Antibacterial effect of DRE-AgNPs was evaluated against Escherichia coli and Staphylococcus aureus. DRE presented mainly tannins and saponins. Additionally, the absorbance of each DRE-AgNPs was positively correlated to DRE concentration. At higher DRE concentrations, AgNPs were larger, regarding Z average; tended to monodispersity; and presented more negative Zeta potentials. Hydrodynamic diameters of DRE-AgNPs were measured by number distribution and only AgNPs synthesized with DRE 2 mg ml−1 (DRE-AgNPs 2) presented a single population of particles. Thus, DRE-AgNP 2 was analyzed by AFM and exhibited a spherical shape and an average height of 18.39 ± 1.59 nm. Most of DRE-AgNPs presented antibacterial effects against E. coli and S. aureus at 128 or 256 µmol l−1. In conclusion, different DRE concentrations modulated physico-chemical characteristics of AgNPs with antibacterial activity. [ABSTRACT FROM AUTHOR]

The green synthesized silver nanoparticles get much attention because of less toxicity, friendly environmental method, and their potential properties in various applications. Herein, the silver nanoparticles named as P.Gua-AgNPs or T.Ind-AgNPs are respectively fabricated by the oxidation–reduction reactions between silver ion and Psidium guajava or Tamarindus indica leaf extract. The Ultraviolet–visible spectrum of P.Gua-AgNPs appears the 429-nm peak while the peak of T.Ind-AgNPs is at 491 nm. The transmission electron microscopy and scanning electron microscope images show the P.Gua-AgNPs are spherical, triangular and plate-like polyshaped morphology in 5–53 nm, the T.Ind-AgNPs have spherical shape in 12–91 nm. The Fourier transform infrared spectra reveal that the particle surface contains the organic functional groups that is consisted with the elemental analysis from the energy dispersive X-ray analysis indicating the presence of C, O and Ag. So the Psidium guajava leaf extract containing abundant polyphenols, polyols, aldehyde content, and sulfur compounds creates the P.Gua-AgNPs with smaller size, narrower distribution, more diversified morphology than T.Ind-AgNPs fabricated from Tamarindus indica leaf extract being rich of organic acid and vitamin C. In addition, T.Ind-AgNPs and P.Gua-AgNPs show the highly antifungal ability against Fusarium oxysporum, Aspergillus niger, and Aspergillus flavus. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were decorated onto functionalized carbon nanotubes (Ag/f-MWCNTs) using a green method under sunlight conditions. The as-synthesized composite was characterized by UV–vis spectroscopy, XRD, FTIR, SEM, and TEM microscopy. In Ag/f-MWCNTs composite, synthesized NPs were spherically shaped, with particle size ranging from 17.1 to 30.5 nm. The photocatalytic degradation activity of Ag/f-MWCNTs composite was evaluated for the degradation of the cationic methylene blue (MB) dye solution. The rate constants for photocatalytic dye degradation were 0.012 and 0.051 min−1 for f-MWCNT and Ag/f-MWCNTs respectively. Compared with that of f-MWCNTs, Ag/f-MWCNTs composite showed high dye degradation activity after irradiation for 60 min. In addition, photocatalytic bacterial inhibition was studied for the gram-negative bacterium Escherichia coli at different time intervals under visible light irradiation. Ag/f-MWCNTs exhibited maximum photocatalytic bacteria inactivation after 120 min. Based on the obtained results, Ag/f-MWCNTs are a tremendously efficient photocatalyst for the degradation of toxic dyes and bacteria inactivation, and the synthesized material serves as an efficient component for wastewater treatment. [ABSTRACT FROM AUTHOR]

A simple and easy green synthesis of silver nanoparticles (Ag NPs) was prepared using Sapindus emarginatus stem bark extract and anchored over graphitic carbon nitride (g-C3N4) surface. The synthesized materials characterized by UV–Visible, XRD, FESEM, FETEM, FT-IR and Raman spectroscopy ensured the development of Ag NPs anchored over the g-C3N4 surface. The prepared catalyst was utilized for Methylene Blue (MB) dye degradation through visible light photocatalysis. The optimization of operational parameters, like the effect of catalyst dosage, H2O2 concentration and slurry pH, was performed. The results exhibited that compared to pristine g-C3N4, photocatalytic efficacy was enhanced two-fold in Ag@g-C3N4. Also, the prepared Ag@g-C3N4 showed a faster catalytic MB dye reduction (25 s) in the presence of NaBH4. The catalyst was recovered from the reaction solution by centrifugation and reused for five consecutive cycles. The results showed that there was no significant loss in the efficiency of the catalyst. These results confirmed that the green synthesized Ag@g-C3N4 is likely advantageous for organic pollutants degradation. [ABSTRACT FROM AUTHOR]

The synthesis of nanoparticles by biological routes may leads to the development of clean, non-toxic and environmentally acceptable green chemistry procedures. In this context, the present study was aimed to synthesize silver nanoparticles (AgNPs) using the leaf extract of Parthenium hysterophorus and to evaluate its antibacterial and anticancer activity. The synthesized AgNPs were characterized by UV–Vis, FTIR, XRD and TEM. The AgNPs were tested against clinical pathogens viz. Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and Enterococcus faecalis with the maximum zone of inhibition 18, 19, 13, 17 and 12 mm, respectively at 80 µg/ml concentration. The cytotoxic assay (MTT) of synthesized AgNPs against HepG2 liver cancer cells showed significant inhibition by reducing cell viability below 50% at 53 μg/ml concentration promising the anticancer effect. The wound healing assay was performed to confirm the proliferation of HepG2 cells and the inhibition of growth observed at 50 µg/ml concentration in the 24 h treatment of AgNPs when compared with control. It was eventually concluded that the synthesized AgNPs showed promising antibacterial and anticancer activity against HepG2 liver cancer cells by promoting the inhibition of cell proliferation and migration on very low concentration. [ABSTRACT FROM AUTHOR]

In the present work, AgNPs have been prepared using an extract of Exserohilum rostrata, an endophyte fungus isolated from Ocimum tenuiflorum leaf and characterized using TEM, SEM, DLS, XRD, FT-IR, etc. The FT-IR analysis confirmed the capping of AgNPs with bioactive molecules of endophyte extract, thereby importing addition or enhancing inherent AgNPs therapeutic properties. Both endophyte extract and AgNPs offered significant inhibition in Gram-positive and Gram-negative bacteria. Further, we also demonstrated its ability to inhibit bacterial biofilm formation of P. aeruginosa and S. aureus. Furthermore, we also demontrated excellent antioxidant and anti-inflammatory activity of both endophyte extract and AgNPs. Moreover, we observed ehanced antibacterial, anti-inflammatory, and antioxidant activity of AgNPs which is due to the synergistic effect of the bioactive agent forming the corona of AgNPs and with inhabitant activity of AgNPs. We also demonstrated the antimitotic activity in A. cepa and antiproliferative activity in breast cancer cells. AgNPs have also found to be excellent compatibility with healthy human keratinocyte cells and RBC cells. Hence, we might say that biogenically synthesized AgNPs using endophyte extract possess anti-bacterial, anti-inflammatory, and anti-oxidant ability as well as antiproliferative activity in breast cancer cells and thus possible found its application in the biomedical industry due to it's eco-friendly and cost-effectiveness. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticle was green synthesized using the leaf extract of Solanum nigrum (Sn-AgNPs) and bio-physically characterized by UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), High resolution transmission electron microscopy (HR-TEM), Zeta potential analysis and Energy dispersive X-ray (EDX) analysis. The ecotoxicity of silver nanoparticle (Sn-AgNPs) were tested against both invertebrate (Ceriodaphnia cornuta and Paramecium sp.) and vertebrate aquatic animal models (Guppy fish, Poecilia reticulata) in comparison with bare silver nitrate. Sn-AgNPs were observed to be less toxic than ionic silver (silver nitrate). The ecotoxicity levels of Sn-AgNPs were found to be varied between tested organisms. Sn-AgNPs caused 100% mortality of freshwater crustacean, C. cornuta at 50 µg mL−1. At concentration below 50 µg mL−1 (10–30 µg mL−1), abnormality in the swimming behavior of C. cornuta was noticed. The ingestion and accumulation of Sn-AgNPs in the intestine of C. cornuta neonates were visualized under light and confocal laser scanning microscopic images. The ecotoxicity of Sn-AgNPs to the freshwater protozoan ciliate, Paramecium sp. showed that 30 µg mL−1 were lethal and produced 100% mortality at the same concentration. The study concludes that Sn-AgNPs was less toxic to both invertebrate and vertebrate models compared to ionic silver nitrate. [ABSTRACT FROM AUTHOR]

While manufacturing silver nanoparticles (Ag-NPs) by green chemical rout, here we presented a naive, bottom-up and green rout for the production of Ag-NPs by successfully employed for catalytic degradation of ibuprofen drug. The Cefditoren derived silver nanoparticles were optimized by Ultra Violet–Visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and high-resolution transmission electron microscope analysis. This work has shown that a comprehensive degradation of ibuprofen of about ~ 99.9% was attained in little reaction time (60 s) by nimble Cef-Ag-NPs. The precision was achieved in percent degradation of ibuprofen by altering and adjusting the reaction period, quantity, and concentration of catalyst. The calculated rate constant (K) value for ibuprofen catalytic degradation was attained in 8 × 10−2 S−1 by plotting in concentration (C) versus time (s). The bactericidal potency of fabricated Cef-Ag-NPs was also assessed for the preferred Gram-positive Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogens) and Gram-negative Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium) bacterial species. The outcomes were inveterate that common antibiotic in amalgamation with silver nanoparticles had strong and drastic antibacterial effects as compared to individually treated antibiotic and silver ions. On behalf of these consequences, it was realized that concerning Cef-Ag-NPs would serve as fast, economic, and less conventional candidates for other harmful and antibiotic-resistant pathogens. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag NPs) were profitably synthesized from aqueous Amorphophallus paeoniifolius leaf extract at room temperature, using one step and eco-friend green synthesis. The leaf extract acts as reducing agent to the formation of Ag NPs from Ag+ ions. The development of Ag NPs through aqueous medium was confirmed by UV–Vis spectroscopy and the spectra show characteristic surface plasmon resonance of Ag NPs at 428 nm. Crystalline nature of the synthesized samples was affirmed by the XRD studies. The particles are predominantly grown via (111) plane of Ag crystal and the particles size was fall in the range of 20–26 nm calculated by Scheerrer's formula. Size and shape of Ag NPs were observed from the SEM and TEM characterization. The samples are almost having spherical shape particles and the size of the particles is lies between 20 and 30 nm. The energy peak at 3 keV in the EDS spectrum strongly supported that the synthesized sample is Ag. FTIR spectra exhibit the leaf extract containing various characteristic functional groups which should responsible for the reduction of Ag+ ions. Synthesized Ag NPs displayed as potential antibacterial candidate against both gram positive and gram negative bacterial. [ABSTRACT FROM AUTHOR]

In the present study one-pot green fabrication of silver nanoparticles (Ag NPs) with aqueous leaf extract of Lilium lancifolium. Synthesized Ag NPs were illustrated by UV–Vis, FT-IR, XRD, AFM and TEM analysis. A surface plasmon resonance peak was noticed at 411 nm in UV–Vis analysis. XRD patterns of Ag NPs showed high crystalline nature with face centered cubic structure. AFM and TEM analysis of Ag NPs exhibit special and anisotropic morphology with accurate particle size about 10–70 nm and average mean value of 45 nm. Ag NPs were tested for antibacterial and anti-biofilm activity against Gram positive and Gram-negative bacterial strains. The exposure to 25 µL exhibited better antibacterial activity and 50 µL significantly control the bacterial biofilm growth. Overall, the proposed green synthesis method of Ag NPs is facile, convenient, less time consuming and environmentally safe. [ABSTRACT FROM AUTHOR]

Breast cancer remains the second common cause of cancer death in United State women in 2018. Consequently, it is of growing need to explore new strategies to treat cancer at various stages of breast cancer. This review discussing the efficacy of biogenic silver nanoparticles (AgNPs) against breast cancer and/or normal cells and its mechanisms of AgNPs toxicity. The research articles were systematically collected through databases including Cochrane, Web of Science, PubMed, Scopus, Science Direct, ProQuest, Google Scholar, and Embase. Significantly, most of the studies were carried out on MCF-7 cancer cell line. Furthermore, the general approach was phyto-fabrication of AgNPs. Specifically, a hefty 71.27% of studies employed plants to bio-fabricate AgNPs. Additionally, fungi with 14.89% of the studies were the second predominant resources conducted for synthesis of AgNPs. Majority of studies bio-fabricated spherical AgNPs with an average diameter of less than 100 nm. Interestingly, the general approach suggested significant toxic effects of biogenic AgNPs with inhibitory concentration of 50% in breast cancer cell lines, while less toxicity was reported in normal cell lines. Regarding the recent advantages in cancer nanomedicine, it is expected that biogenic AgNPs may emerge as potential breast cancer therapeutic agents alone or in combination with FDA-approved anti-cancer drugs in the near future. [ABSTRACT FROM AUTHOR]

The aim was to investigate the inhibitory activities on AGE formation by testing silver nanoparticles fabricated using a methanol extract of Eysenhardtia polystachya (EP-AgNPs) and characterized using various physicochemical techniques. The in vitro glucose-albumin assay was used, and cell viability was carried out in RAW264.7 cells. For In vivo testing, we induced diabetes in adult zebrafish with by providing a high blood glucose concentration. EP-AgNPs showed an absorption peak at 413 nm in the UV-Vis spectrum, indicating surface plasmon resonance of the nanoparticles. TEM indicated that most of the particles were spherical, with a diameter of 10-12 nm, a polydispersity index of 0.197, and a zeta potential of − 32.25 mV, suggesting high stability of the nanoparticles. The biocompatible nature of the EP-AgNPs was demonstrated in RAW264.7 cells. EP-AgNPs markedly reduced the formation of AGEs, Amadorin-product/fructosamine, Nε-(carboxymethyl)-lysine, amyloid cross β-structure, and protein carbonyl content in BSA-glucose system and increased total thiol-group after 4 weeks in hyperglycemic zebrafish, EP-AgNPs provided a protective effect against glycation. Data suggest that the inhibitory activity of EP-AgNPs on formation of AGEs is developed through a multiple-stage mechanism of glycation. EP-AgNPs could therefore be an antiglycation agent for prevention diabetic complications. [ABSTRACT FROM AUTHOR]

Mosquito control is facing a challenge worldwide, due to ineffectiveness of chemical insecticides. Identification of novel and ecofriendly insecticides is the need of the hour. In the present study mosquito control efficacy, antioxidants and anti-cancerous potential of silver nanoparticle conjugated with Carmona retusa (Vahl) Masam nanoparticles. Synthesized nanoparticles had UV absorption maximum at 420 nm, size ranging between 20 and 40 nm based of TEM, has cubic structure, C-H bending and Ag Metal bands. Results show high free radical scavenging ability of C. retusa derived silver nanoparticles as evidenced by DPPH radical and H2O2 radical assay. C. retusa derived nanoparticles produce 80% inhibition in MCF-7 cell line at concentration of 500 μg/ml. High larvicidal activity with LC50 values of 116.681 ppm for Anopheles stephensi, 198.766 ppm for Aedes aegypti, and 83.553 ppm for Culex quinquefasciatus were observed. Based on the findings of the study we suggest that C. retusa plant mediated AgNPs has anticancerous and mosquito larvicidal property and could be bioprospected for drug development and mosquito control. [ABSTRACT FROM AUTHOR]

A straightforward and environmentally benign method for the synthesis of silver nanoparticles (AgNPs) is reported in this paper. A sustainable and nontoxic polysaccharide carboxy methyl cellulose (CMC) was used as both reducing agent and stabilizer in the process of synthesizing AgNPs. By varying the precursor concentration, solution pH value, reaction temperature and duration, the highly stable and smaller sized AgNPs with narrow size distribution were obtained. The as-synthesized AgNPs were characterized using UV-Vis absorption spectroscopy, high resolution transmission electron microscopy, X-ray diffraction and zeta potential and size analyzer. Measurements of optical spectra showed that the surface plasmon resonance was localized around 404 nm. The TEM images showed that the particles are well dispersed and spherical in shape with an average particle diameter of 11.64 ± 2.32 nm which is less than the value (13.12 ± 1.54 nm) measured by dynamic light scattering. The zeta potential value of AgNPs was measured to be − 62.8 mV which indicated that CMC coated on the surface of as-synthesized AgNPs resulting in the negatively charged surface and the stable in nature. The prepared silver nanoparticles are effective in inhibiting the growth of both gram positive Staphylococcus aureus and gram negative Escherichia coli. [ABSTRACT FROM AUTHOR]

A green synthesis of composite based on silver nanoparticles (AgNPs) obtained by Melissa officinalis (MO) extract and supported on diatomaceous earth (DE) was synthesized. Kinetic adsorption models were proposed to describe the sorption mechanism of AgNPs nanoparticles during the impregnation process. Theoretical models as pseudo first order, pseudo-second order, Elovich and intraparticle diffusion were developed to establish accurately the kinetic parameters, such as correlations factors (R2) and maximum Ag nanoparticles sorption capacity of the diatomite. According to the Kinetic adsorption parameters obtained, the pseudo-second order model reveals the best linear fit. Also, four types of pseudo-second order model were performed and analyzed. The proposed models describe with great precision, the adsorption mechanism of Ag nanoparticles during the impregnation process onto DE surface. Complementary, the antibacterial activity of the composite against Staphylococcus aureus and Escherichia coli were evaluated. The green composite (Ag nanoparticles/diatomaceous earth) was characterized by Electron Microscopy, X-Ray Diffraction and Infrared Spectroscopy. [ABSTRACT FROM AUTHOR]

Biosynthesis of silver nanoparticles has received considerable attention due to their cost-effective, eco-friendly and medicinal values. In this study, silver nanoparticles (Ag NPs) were synthesised using the aqueous leaf extracts of Piper nigrum. TEM images revealed that the particle is spherical with 20–50 nm in size. Furthermore, to evaluate the toxicity of synthesized Ag NPs, fish Labeo rohita were exposed to two different concentrations (2.5 µg/L as the treatment I and 5 µg/L as treatment II) for 35 days, and antioxidant parameters and histology of gill, liver and kidney were examined. A biphasic response in the activity of glutathione S-transferases (GST) was observed in gill and liver of fish. GST activity in the kidney of fish was significantly increased when compared to control group. Glutathione reductase (GR) activity in organs/tissue of fish were found to be increased while peroxidase (POD) activity was significantly decreased. Histopathological changes such as hyperplasia, proliferation of epithelial cells and fusion of lamellae were observed in both the concentrations. In liver, necrosis, nuclear degeneration and dilation of sinusoids were observed. Subsequently, the representative effects of POD activity were assessed based on the Box–Behnken Equation, 3-D contour plot and ANOVA analysis through response surface methodology analysis. [ABSTRACT FROM AUTHOR]

We report a facile, cost effective, and environmentally friendly green chemistry method for preparing silver nanoparticles (AgNPs) using Rubus crataegifolius bge (RCB) fruit extract. The amount of the fruit extract used was found to be important parameters in the growth of AgNPs. In this study, the effect of RCB fruit extract on the synthesis of AgNPs was studied using UV-Vis spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD), and dynamic light scattering analyses were performed to characterize the RCB fruit extract-stabilized AgNPs. The formation of the AgNPs was confirmed by the color change of the reaction medium and the absorbance peak observed at 420 nm. The XRD analysis confirmed the face centered cubic structure of the AgNPs. The catalytic property of the as-synthesized AgNPs was analyzed for the reduction of 4-nitrophenol to 4-aminophenol. [ABSTRACT FROM AUTHOR]

A facile and green route for the synthesis of metallic nanoparticles is of significant intriguing, as it provides simple, rapid, clean, nontoxic, easily available, energy-efficient, cost-effective fabrication method. We reported environmentally benign and unexplored plant Aglaia elaeagnoidea flower extract for the synthesis of spherical and crystalline silver (Ag) and gold (Au) nanoparticles with an excellent robustness against agglomeration. The resultant nanoparticles were characterized using UV-Vis spec., FTIR, XRD, FESEM, EDAX, and TEM techniques. The uniqueness of our method lies in fast synthesis (10 min for Ag NPs) and ultra rapid homogeneous and heterogeneous complete degradation of Methylene Blue and Congo Red within few seconds using the synthesized Ag and Au NPs as the catalyst, respectively. Whereas more than 90% conversion of 4-Nitrophenol to 4-Aminophenol within few minutes for homogenous and few seconds for heterogeneous method using Ag and Au NPs were obtained. Hence, the results of this study demonstrate the possible application of biosynthesized of Ag and Au NPs as nanocatalyst in waste water treatment. [ABSTRACT FROM AUTHOR]

Green synthesis of metal nanoparticles using earth abundant materials in the absence of any toxic solvent, reducing agent and protecting group is one of the emerging areas of research in materials chemistry. Herein, we report a green method for the synthesis of silver nanoparticles (AgNPs) using Actinodaphne madraspatana Bedd leaf extract as reducing as well as stabilizing agent. To our delight, AgNPs of different sizes could be readily synthesized by simply changing the pH of plant extract and the average size of AgNPs were found to be 60, 35 and 20 nm at pH 6, 9 and 12 respectively. The efficacy of prepared AgNPs towards the catalytic reduction of 4-nitrophenol (4-NP) has been investigated and the nanocatalysts have demonstrated excellent catalytic activity as evidenced from the rate constants. The kinetics of reduction reaction follows Langmuir-Hinshelwood mechanism, based on which the rate constant ' k' was calculated. The effect of catalyst dosage, concentration of 4-NP, concentration of NaBH and size of AgNPs towards catalytic reduction of 4-NP has been systematically investigated. It was interesting to notice that the AgNPs have exhibited size dependent catalytic activity towards reduction of 4-NP and the catalytic activity was found to increase with decrease in particle size. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The present study focused on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea (ground nut) root extract for the antibacterial and clinical application. The presence of major phytochemical compounds are found to be 2H-Pyaran,2,5-diethenyltetrahydro, Didodecyl phthalate, Decanoic acid, Tetradecanoic acid, Bis(2-ethylhexyl) phthalate, Dodecanoic acid, Phosphonic acid, 2-(4-Methoxyphenyl)-5-(4-methoxynaphthyl) thiophene and Methyl 2-(N-Benzylimino)-4-chloro-3,3-dimethylbutanoate by GC-MS. Nanoparticles synthesis is confirmed by UV-Vis analysis by observing the maximum absorption spectrum at 450 nm. XRD and SEM-EDX results reveals the synthesized nanoparticles are cubic crystalline with agglomerated particles of silver oxide with biomolecules present around it. TEM images clearly shows that the biosynthesized nanoparticles are mostly spherical and irregular shaped with an average particles size of 30 nm. Highest susceptibility pattern of silver nanoparticle against Enterococcus sp. (35 ± 0.4 mm) which followed by Pseudomonas sp. (33 mm) and Staphylococcus aureus (29 mm). Green synthesized nanoparticles are coated over the commercially available clinical band aid cloth by dip coating method. Silver nanoparticle incorporated band aid cloth showed good antibacterial activity against the harmful bacteria which usually cause infection and interfere during wound healing. Our findings revealed that green nanoparticle has a good antibacterial action against harmful bacteria and showed good response for efficient clinical application. [ABSTRACT FROM AUTHOR]

Compared with cultivated plants, wild weeds are cheaper and wider available for phytogenetic synthesis of nanoparticles. It is very valuable to distinguish the weed species from the local dominant wild plants for both efficient synthesis of nanoparticles and real industrial applications. In this study, a cheap, simple and novel biosynthesis method for silver nanoparticles (AgNPs) using Chenopodium aristatum. L stem extract as reducing and capping agents was developed. The real-time formation of AgNPs was monitored by UV-vis spectroscopy, and the SPR band was located at ~440 nm. The reaction factors including incubation time, AgNO concentration, reaction temperature and pH were discussed and optimized. The synthesized AgNPs were quasi-spherical with the sizes from 3 to 36 nm. HRTEM images and XRD patterns showed that the AgNPs were with the face-centered cubic (fcc) structure. FTIR spectra indicated that some functional groups such like O-H, N-H, C-H, C=O were possibly responsible for reducing silver ions into nanoparticles and acted as capping agents to avoid agglomeration. The synthesized AgNPs exhibited strong catalytic activity in degradation of 4-nitrophenol and good antibacterial activity against E. coli and S. aureus. The proposed phytogenetic synthesis method is economical, simple and feasible. [ABSTRACT FROM AUTHOR]

Mosquitoes are the most critical group of insects in the context of public health, since they transmit key parasites and pathogens, causing millions of deaths annually. Culex tritaeniorhynchus is an important vector of Japanese encephalitis (JE) across urban and semi-urban areas of Asia. In this study, we bio-fabricated silver nanoparticles (Ag NP) using the leaf extract of Bougainvillea glabra as reducing and stabilizing agent. The synthesis of Ag NP was confirmed analyzing the excitation of surface Plasmon resonance using ultraviolet-visible (UV-vis) spectrophotometry. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the clustered and irregular shapes of Ag NP. The presence of silver was determined by energy dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy analysis investigated the identity of secondary metabolites, which may act as Ag NP capping agents. The acute toxicity of B. glabra extract, synthesized Ag NP and a combined treatment testing blends of both mosquitocidals was evaluated against larvae and pupae of Cx. tritaeniorhynchus. B. glabra showed LC of 198.93 (larva I), 234.50 (II), 309.18 (III), 371.69 (IV) and 466.09 (pupa) µg/ml, Ag NP LC ranged from 7.77 (I) to 19.44 µg/ml (pupa). Combined treatments with B. glabra leaf extract plus 5.12.5 µg/ml of Ag NP lowered the botanical LC to 66.09 (I), 76.48 (II), 99.02 (III), 133.43 (IV) and 179.74 µg/ml (IV), respectively. The effectiveness of green-fabricated Ag NP against the JE vector was confirmed in adulticidal tests, as well as evaluating the impact of Ag NP on fecundity and longevity of adult mosquitoes. Lastly, the larvicidal effectiveness of Ag NP was confirmed in the field, treating sewage water bodies. Overall, this study suggests that the green-synthesized Ag NP fabricated using B. glabra can be considered a potential mosquito control device against the JE vector, C. tritaeniorhynchus in Asian regions. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were synthesized using an aqueous Perilla leaf extract and evaluated for anticancer activity. These green -synthesized AgNPs were characterized using UV-Visible absorption spectroscopy, XRD, TEM, and SAED. The synthesized AgNPs were spherical and hexagonal in shape, and the average size of the NPs was ~23 nm. SRB assay investigated the anticancer activity of the AgNPs against human cervical cancer (HeLa) cells. The fluorescence and confocal microscopy studies were confirmed the DNA damage and apoptosis following nanoparticle treatment. Furthermore, the intracellular ROS was also increased after treatment. Taking all these data together, it is suggested that AgNPs may be a potential agent for the inhibition of cervical tumor cells. [ABSTRACT FROM AUTHOR]

Mosquito vector control is a crucial challenge nowadays. Recently, the relevance of screening poorly studied plant products for green synthesis of nanopesticides was highlighted. Different plant products for nanosynthesis led to nano-composites with distinct biophysical features and toxicity. Here we fabricated silver nanoparticles capped with metabolites from Fumaria indica aqueous extract. Several biophysical methods were used to validate nanosynthesis F. indica-synthesized nanomaterial showed high efficacy as pesticide on Anopheles subpictus (LC = 10.34 µg/ml), Aedes albopictus (LC = 11.42 µg/ml) and Culex tritaeniorhynchus (LC = 12.50 µg/ml) larvae, allowing us to propose this easy to obtain nano-material as an effective source of novel mosquito pesticides. [ABSTRACT FROM AUTHOR]

The green synthesis of silver nanoparticles (AgNPs) has been proposed as a simple, eco-friendly and cost effective alternative to chemical and physical methods. The Rhus chinensis plant is one of the well studied medicinal plant and its galls find excellent clinical and therapeutic applications. The present study reports the use of water extract from galls of R. chinensis as a reducing agent and formation of AgNPs from silver nitrate solution by a green synthesis route. The AgNPs formation was observed visually by color change and the absorbance peak at 450 nm was observed by UV-Visible spectrophotometer. The shape, size, and morphology of synthesized AgNPs were monitored by transmission electron microscopy and field-emission scanning electron microscopy. The face centered cubic structure of AgNPs was confirmed by X-ray diffraction pattern and element composition by energy dispersive X-ray analysis. The Fourier transform infrared spectroscopy spectrum revealed that the presence of components acts as a reducing and capping agent. The antibacterial activity was performed using the agar well diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration were determined by broth dilution and spread plate method respectively. Synthesized nanoparticles were spotted as triangular and hexagonal shape and the particle size was around 150 nm. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag-NPs) have been synthesized using extract of Chelidonium majus root in aqueous solution at room temperature. The root extract was able to reduce Ag to Ag and stabilized the nanoparticles Different physico-chemical techniques including UV-Vis spectroscopy, transmission electron microscopy and powder X-ray diffraction (PXRD) were used for the characterization of the biosynthesized Ag-NPs obtained. The surface plasmon resonance band appeared at 431 nm is an evidence for formation of Ag-NPs. TEM imaging revealed that the synthesized Ag-NPs have an average diameter of around 15 nm and with spherical shape. Moreover the crystalline structure of synthesized nanoparticles was confirmed using XRD pattern. Furthermore antimicrobial activities of synthesized Ag-NPs were evaluated against Escherichia coli -ATCC 25922 and Pseudomonas aeruginosa ATCC 2785 bacteria strain. [ABSTRACT FROM AUTHOR]

In this work we reported an optical sensor for the detection of dissolved ammonia through the green synthesis of silver nanoparticles (AgNPs) using aqueous fruit extract of Terminalia chebula. The formation of AgNPs was monitored by visual observation and the detection of Surface Plasmon Resonance (SPR) peak using UV-Vis spectrophotometer. The naked eye visual inspection revealed the rate of formation of AgNPs in control reaction (absence of ammonia) is slower than that of other ammonia contained solutions which was confirmed from the UV-Vis spectroscopic results. The absorbance intensity of AgNPs was linearly (R = 0.9850) correlated with the concentration of dissolved ammonia from 0 to 100 ppm. The formation of diamine silver complex and ammonium phenolate ion increases the SPR absorbance intensity of AgNPs. The blue shift of SPR peak, while increasing concentration of ammonia is due to the size decreasing of AgNPs, which was confirmed from the HR-TEM analysis. [ABSTRACT FROM AUTHOR]