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Journal ArticleDOI

A novel green synthesis of silver nanoparticles and their catalytic action in reduction of Methylene Blue dye

01 Sep 2017-Sustainable Environment Research (No longer published by Elsevier)-Vol. 27, Iss: 5, pp 245-250
TL;DR: An eco-friendly and facile method for biogenic synthesis of silver nanoparticles (AgNPs) has been developed using fruit extract of Gmelina arborea, an abundantly available medicinal plant in North Eastern region of India.
About: This article is published in Sustainable Environment Research.The article was published on 2017-09-01 and is currently open access. It has received 192 citations till now. The article focuses on the topics: Silver nanoparticle & Cost effectiveness.
Citations
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Journal ArticleDOI
TL;DR: This review summarizes the current state of knowledge regarding the use ofsilver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.
Abstract: The current scenario of water resources shows the dominance of pollution caused by the draining of industrial effluents. The polluted waters have resulted in severe health and environmental hazards urging for a suitable alternative to resolve the implications. Various physical and chemical treatment steps currently in use for dye effluent treatment are more time consuming, cost-intensive, and less effective. Alternatively, nanoparticles due to their excellent surface properties and chemical reactivity have emerged as a better solution for dye removal and degradation. In this regard, the potential of silver nanoparticles in dye effluent treatment was greatly explored. Efforts were taken to unravel the kinetics and statistical optimization of the treatment conditions for the efficient removal of dyes. In addition, the role of silver nanocomposites has also experimented with colossal success. On the contrary, studies have also recognized the mechanisms of silver nanoparticle-mediated toxicity even at deficient concentrations and their deleterious biological effects when present in treated water. Hence, the fate of the silver nanoparticles released into the treated water and sludge, contaminating the soil, aquatic environment, and underground water is of significant concern. This review summarizes the current state of knowledge regarding the use of silver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.

209 citations

Journal ArticleDOI
TL;DR: The results indicated that LBG-cl-Poly(DMAAm) hydrogel can be used as an alternative and promising adsorbent to be applied in the treatment of effluents containing the BG dye.

164 citations

Journal ArticleDOI
20 Jun 2019-PLOS ONE
TL;DR: Biosynthesized AgNPs showed a broad-spectrum anti-cancer activity with PDT therapy and therefore represent promoting ROS generation by modulating mitochondrial apoptosis induction in MCF7 breast cancer cells.
Abstract: In this study, we report on the synthesis of silver nanoparticles (AgNPs) from the leaf extracts of Cynara scolymus (Artichoke) using microwave irradiation and the evaluation of its anti-cancer potential with photodynamic therapy (PDT). Silver nanoparticles formation was characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Silver nanoparticles formation was also investigated the surface charge, particle size and distribution using zetasizer analysis. The cytotoxic effect of AgNPs and/or PDT was studied by MTT assay and migration by the scratch assay. The apoptotic inducing ability of the AgNPs and/or PDT was investigated by intracellular ROS analysis, antioxidant enzyme levels (SOD, CAT, GPx and GSH), Hoechst staining and Bax/Bcl-2 analysis using western blotting. The mean particle size of produced AgNPs was found 98.47±2.04 nm with low polydispersity (0.301±0.033). Zeta potential values of AgNPs show -32.3± 0.8 mV. These results clearly indicate the successful formation of AgNPs for cellular uptake. Mitochondrial damage and intracellular ROS production were observed upon treatment with AgNPs (10μg/mL) and PDT (0.5 mJ/cm2) showed significant reducing cell migration, expression of Bax and suppression of Bcl-2. Significantly, biosynthesized AgNPs showed a broad-spectrum anti-cancer activity with PDT therapy and therefore represent promoting ROS generation by modulating mitochondrial apoptosis induction in MCF7 breast cancer cells.

156 citations

Journal ArticleDOI
TL;DR: Green synthesis of silver nanoparticles was done using leaf extracts of Azadirachta indica using flavonoids and terpenoids present in the extract, which is a very rapid and cost-effective method for generation ofsilver nanoparticle at room temperature, however, its exact dose in water purification has to be determined.
Abstract: In this study, green synthesis of silver nanoparticles was done using leaf extracts of Azadirachta indica. The flavonoids and terpenoids present in the extract act as both reducing and capping agent. Microbes (Escherichia coli and Gram-positive bacteria) were isolated from borewell water using selective media. The silver nanoparticles showed antimicrobial activities against Gram-positive bacteria and E. coli. However the silver nanoparticles were more effective against E. coli as compared to Gram-positive bacteria. Various techniques were used to characterize synthesized silver nanoparticles such as DLS and UV–visible spectrophotometer. The absorbance peak was in the range of 420–450 nm, that varied depending upon the variation in the concentration of neem extract. This is a very rapid and cost-effective method for generation of silver nanoparticle at room temperature, however, its exact dose in water purification has to be determined.

121 citations


Cites background from "A novel green synthesis of silver n..."

  • ...require high pressure, temperature, energy and toxic chemicals (Saha et al. 2017)....

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  • ...Materials in the nano-dimensions (1–100 nm) have very high surface to volume ratio that gives them certain unique properties that are different from the same material in bulk which are useful in different fields such as electronics, photonics, biomedical, catalysis, etc.(Saha et al. 2017)....

    [...]

  • ...Green synthesis is preferred over conventional synthesis because it is ecofriendly, cost-effective, single-step method that can be easily scaled up for large scale synthesis and does not require high pressure, temperature, energy and toxic chemicals (Saha et al. 2017)....

    [...]

  • ...Materials in the nano-dimensions (1–100 nm) have very high surface to volume ratio that gives them certain unique properties that are different from the same material in bulk which are useful in different fields such as electronics, photonics, biomedical, catalysis, etc.(Saha et al. 2017)....

    [...]

References
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Journal ArticleDOI
TL;DR: A review of gold nanoparticles can be found in this article, where the most stable metal nanoparticles, called gold colloids (AuNPs), have been used for catalysis and biology applications.
Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

11,752 citations

Book
03 Jul 1995
TL;DR: In this paper, the authors developed the theoretical tools of photonics using principles of linear algebra and symmetry, emphasizing analogies with traditional solid-state physics and quantum theory, and investigated the unique phenomena that take place within photonic crystals at defect sites and surfaces, from one to three dimensions.
Abstract: Since it was first published in 1995, Photonic Crystals has remained the definitive text for both undergraduates and researchers on photonic band-gap materials and their use in controlling the propagation of light. This newly expanded and revised edition covers the latest developments in the field, providing the most up-to-date, concise, and comprehensive book available on these novel materials and their applications. Starting from Maxwell's equations and Fourier analysis, the authors develop the theoretical tools of photonics using principles of linear algebra and symmetry, emphasizing analogies with traditional solid-state physics and quantum theory. They then investigate the unique phenomena that take place within photonic crystals at defect sites and surfaces, from one to three dimensions. This new edition includes entirely new chapters describing important hybrid structures that use band gaps or periodicity only in some directions: periodic waveguides, photonic-crystal slabs, and photonic-crystal fibers. The authors demonstrate how the capabilities of photonic crystals to localize light can be put to work in devices such as filters and splitters. A new appendix provides an overview of computational methods for electromagnetism. Existing chapters have been considerably updated and expanded to include many new three-dimensional photonic crystals, an extensive tutorial on device design using temporal coupled-mode theory, discussions of diffraction and refraction at crystal interfaces, and more. Richly illustrated and accessibly written, Photonic Crystals is an indispensable resource for students and researchers.Extensively revised and expanded Features improved graphics throughout Includes new chapters on photonic-crystal fibers and combined index-and band-gap-guiding Provides an introduction to coupled-mode theory as a powerful tool for device design Covers many new topics, including omnidirectional reflection, anomalous refraction and diffraction, computational photonics, and much more.

8,188 citations

Journal ArticleDOI
TL;DR: It is observed that the slow rate of the reaction along with the shape directing effect of the constituents of the extract are responsible for the formation of single crystalline gold nanotriangles.
Abstract: Biogenic gold nanotriangles and spherical silver nanoparticles were synthesized by a simple procedure using Aloe vera leaf extract as the reducing agent. This procedure offers control over the size of the gold nanotriangle and thereby a handle to tune their optical properties, particularly the position of the longitudinal surface plasmon resonance. The kinetics of gold nanotriangle formation was followed by UV-vis-NIR absorption spectroscopy and transmission electron microscopy (TEM). The effect of reducing agent concentration in the reaction mixture on the yield and size of the gold nanotriangles was studied using transmission electron microscopy. Monitoring the formation of gold nanotriangles as a function of time using TEM reveals that multiply twinned particles (MTPs) play an important role in the formation of gold nanotriangles. It is observed that the slow rate of the reaction along with the shape directing effect of the constituents of the extract are responsible for the formation of single crystalline gold nanotriangles. Reduction of silver ions by Aloe vera extract however, led to the formation of spherical silver nanoparticles of 15.2 nm +/- 4.2 nm size.

1,801 citations

Journal ArticleDOI
TL;DR: It may be said that the NiS/Pt/Ti counter electrode is a promising catalytic material to replace the expensive platinum in FDSSCs.
Abstract: A composite film of nickel sulfide/platinum/titanium foil (NiS/Pt/Ti) with low cost and high electrocatalytic activity was synthesized by the use of an in situ electropolymerization route and proposed as a counter electrode (CE) catalyst for flexible dye-sensitized solar cells (FDSSCs). The FDSSC with the NiS/Pt/Ti CE exhibited a comparable power conversion efficiency of 7.20% to the FDSSC with the platinum/titanium (Pt/Ti) CE showing 6.07%. The surface morphology of the NiS/Pt/Ti CE with one-dimensional (1D) structure is characterized by using the scanning electron microscopy (SEM). The NiS/Pt/Ti CE also displayed multiple electrochemical functions of excellent conductivity, great electrocatalytic ability for iodine/triiodine, and low charge transfer resistance of 2.61 ± 0.02 Ω cm2, which were characterized by using the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization plots. The photocurrent-photovoltage (J-V) character curves were further used to calculate the theoretical optical light performance parameters of the FDSSCs. It may be said that the NiS/Pt/Ti counter electrode is a promising catalytic material to replace the expensive platinum in FDSSCs.

1,036 citations

Journal ArticleDOI
TL;DR: In this paper, a review of conjugated polymers with 1D and 2D topological structures is presented, and a design approach for the alternating donor-acceptor (D-A) copolymers is proposed.

668 citations