Green Synthesis of Biopolymer-Silver Nanocomposites for Gas Sensing

2016 ◽  
Vol 99 ◽  
pp. 54-60 ◽  
Author(s):  
Shilpa A. Pande
Keyword(s):  
Silver Nanoparticles ◽  
Optical Sensors ◽  
Gas Sensing ◽  
Low Cost ◽  
Research Work ◽  
Trisodium Citrate ◽  
Nanocomposite Films ◽  
Sem Images ◽  
Natural Polysaccharide ◽  
Vis Spectroscopy

In this research work, a very simple, low cost eco-friendly method is presented for the synthesis of silver nanoparticles to be used in colorimetric optical sensors based on localized SPR (LSPR) measurement for gas ammonia. Silver nitrate salts are reduced using gaur gum which acts as a capping and reducing agent. Commonly used reducing agents such as trisodium citrate or sodium borohydride are replaced by a more environmental friendly natural polysaccharide. Nanocomposite films of ~ 1.5 μm thicknesses were fabricated using Gaur Gum and silver nanoparticles. The uniformity of nanoparticles size was measured by SEM and TEM, while face centred cubic structure of crystalline silver nanoparticles was characterized using the X-ray diffraction technique. The optical properties of the composite film were tested by UV-VIS Spectroscopy. The formation of Gaur Gum/silver nanocomposite films was confirmed using SEM images. Also the resistivity of nanocomposite thin film was measured which could be then used for gas sensing application.

Refractive Index Tailoring of Poly(methylmethacrylate) Thin Films by Embedding Silver Nanoparticles

2012 ◽  
Vol 585 ◽  
pp. 134-138 ◽  
Author(s):  
Alisha Goyal ◽  
Jyoti Rozra ◽  
Isha Saini ◽  
Pawan K. Sharma ◽  
Annu Sharma
Keyword(s):  
Thin Films ◽  
Silver Nanoparticles ◽  
Refractive Index ◽  
Band Gap ◽  
Ag Nanoparticles ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Plasmon Resonance Peak ◽  
Pmma Matrix ◽  
Vis Spectroscopy

Nanocomposite films of Poly (methylmethacrylate) with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag-PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. Thin solid films were structurally characterized using UV-VIS spectroscopy and TEM. The appearance of surface plasmon resonance peak, characteristic of silver nanoparticles at 420 nm in UV-VIS absorption spectra of Ag-PMMA films confirms the formation of Ag-PMMA nanocomposite. TEM showed Ag nanoparticles of average size 8 nm embedded in PMMA matrix. Analysis of absorption and reflection data indicates towards the reduction in optical band gap and increase in refractive index of the resulting nanocomposite. The synthesized Ag-PMMA nanocomposite has been found to be more conducting than PMMA as ascertained using I-V studies. The decrease in band gap and increase in conductivity can be correlated due to the formation of localized electronic states in PMMA matrix due to insertion of Ag nanoparticles. The PMMA thin films with dispersed silver nanoparticles may be useful for nanophotonic devices.

Photocatalytic Comparative Study of TiO2, ZnO, Ag-G-ZnO and Ag-G-TiO2 Nanocomposite Films

2017 ◽  
Vol 751 ◽  
pp. 825-830 ◽  
Author(s):  
Phuri Kalnaowakul ◽  
Tonghathai Phairatana ◽  
Aphichart Rodchanarowan
Keyword(s):  
Colloidal Solution ◽  
Nanocomposite Films ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Photocatalytic Activities ◽  
Xrd Patterns

In this study, the photocatalytic properties and morphology of TiO2, ZnO, Ag-graphene-zinc oxide (Ag-G-ZnO) and Ag-graphene-titanium dioxide (Ag-G-TiO2) nanocomposite were compared. The Ag-G-ZnO and Ag-G-TiO2 nanocomposite were successfully prepared by thermal decomposition of colloidal solution. These prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and photocatalytic activities. The results from XRD patterns show that Ag-G-TiO2 composites and the Ag-G-ZnO nanocomposites were in the form of fcc and hcp crystal structure, respectively. The SEM images show that at calcination of 500 °C for 3 h, the composite thin film of Ag-G-ZnO and Ag-G-TiO2 were homogenous. In the case of the photocatalytic experiments using methylene blue dye (MB) under UV irradiation, the order of the photocatalytic activities from high to low performances are Ag-G-ZnO, Ag-G-TiO2, ZnO and TiO2, respectively.

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 Study of Antibacterial Properties of Ziziphus mauritiana based Green Synthesized Silver Nanoparticles against Various Bacterial Strains

2020 ◽  
Vol 12 (4) ◽  
pp. 1484 ◽  
Author(s):  
M. Asimuddin ◽  
Mohammed Rafi Shaik ◽  
Neeshat Fathima ◽  
M. Shaistha Afreen ◽  
Syed Farooq Adil ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Low Cost ◽  
Preliminary Investigation ◽  
Antibacterial Properties ◽  
Silver Ions ◽  
Ziziphus Mauritiana ◽  
Bacterial Strains ◽  
Vis Spectroscopy ◽  
Ft Ir

Due to their low cost and environmentally friendly nature, plant extracts based methods have gained significant popularity among researchers for the synthesis of metallic nanoparticles. Herein, green synthesis of silver nanoparticles was performed using the aqueous solution of Ziziphus mauritiana leaves extract (ZM-LE) as a bio-reducing agent. The as-obtained silver nanoparticles were characterized by using UV-Vis spectroscopy, XRD (X-ray diffraction), TEM (transmission electron microscopy), and FT-IR (Fourier-transform infrared spectroscopy). In addition, the effects of the concentrations of the leaves extract, silver nitrate, and the temperature on the preparation of nanoparticles were also investigated. In order to determine the nature of secondary metabolites present in leaves extract, a preliminary investigation of phytoconstituents was carried out using different methods including Folin-Ciocalteu and AlCl3 methods. The results have indicated the presence of a considerable amount of phenolic and flavonoid contents in the leaves extract, which are believed to be responsible for the reduction of silver ions and stabilization of resulting nanoparticles. Indeed, the FT-IR spectrum of silver nanoparticles also confirmed the presence of residual phytomolecules of leaves extract as stabilizing ligands on the surface of nanoparticles. The antibacterial properties of as-obtained silver nanoparticles were tested against various bacterial strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis. The nanoparticles strongly inhibited the growth of S. aureus with a minimum inhibitory concentration (MIC) of 2.5 μg/ml and moderately inhibited the growth of E. coli with a MIC of 5 μg/ml.

scholarly journals One-Pot Facile Green Synthesis of Silver Nanoparticles Using Seed Extract of Phoenix dactylifera and Their Bactericidal Potential against MRSA

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Mohammad Azam Ansari ◽  
Mohammad A. Alzohairy
Keyword(s):  
Silver Nanoparticles ◽  
Cell Wall ◽  
Phoenix Dactylifera ◽  
Antibacterial Activities ◽  
Complete Separation ◽  
Sem Images ◽  
One Pot ◽  
Tem Analysis ◽  
Stabilizing Agents ◽  
Vis Spectroscopy

Due to the great economic, health, and medicinal importance, Phoenix dactylifera seeds were chosen for the synthesis of silver nanoparticles (AgNPs) because of their ecofriendly, nonhazardous, cost effectiveness advancement over physical and chemical methods, as green methods are safe, one step, and simple and did not require any chemical reducing and stabilizing agents. The green synthesized AgNPs were characterized by UV-Vis spectroscopy, SEM, HR-TEM, and DLS. Further, the bactericidal activity of synthesized AgNPs against Methicillin-resistant Staphylococcus aureus (MRSA) was investigated by determining MIC/MBC, agar diffusion methods, and electron microscopy. TEM images of the so-formed AgNPs revealed that the NPs were spherical in shape, with a size range of 14–30 nm. The MIC and MBC of AgNPs for MRSA were found to be 10.67±0.94 and 17.33±1.89 μg/ml, respectively. The antibacterial activities were found to be increased with the increasing concentration of AgNPs. The zone of inhibition was greater (24mm) at highest concentrations (500μg/ml) of AgNPs, while smaller (11mm) at lowest concentrations (7.8μg/ml). The SEM images of treated MRSA cells showed wrinkled and damaged cell wall, indicating the disruption and disorganization of membrane. HR-TEM analysis exhibits extensive injury and complete disintegration of cell wall and membrane. Large translucent zones have been seen in the cytoplasm, due to either localized or complete separation of the cell membrane from the cell wall. Overall, these results indicate that green synthesized AgNPs should be considered as an effective treatment and prevention option for the medical devises related infections caused by deadly MRSA and other drug resistant pathogens.

Synthesis and characterization of silver nanoparticles using as a reducing agent plant extract of Dandelion (Taraxacun officianale)

2019 ◽  
pp. 11-17
Author(s):  
Lidia Meléndez-Balbuena ◽  
Eric Reyes-Cervantes ◽  
Blanca Martha Cabrera-Vivas ◽  
Maribel Arroyo
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extract ◽  
Plant Extracts ◽  
Low Cost ◽  
Coli Strain ◽  
Reducing Agent ◽  
Force Microscopy ◽  
Yellow Color ◽  
Golden Yellow ◽  
Vis Spectroscopy

The objective of this work was to synthesize the synthesis of silver nanoparticles using as a reducing agent of ionic silver the plant extract of Dandelion (Taraxacun officianale), vegetable of high availability and low cost, as an alternative to the processes conventional, based on the antioxidant capacity of plant extracts that reduce metals in solution. The nanoparticles prepared by this method were characterized by the golden yellow color characteristic of silver nanoparticle solutions. Measurements with UV-Vis spectroscopy of aqueous solutions of Ag1 + ions after coming into contact with plant extracts of Dandelion at different pHs showed an intense absorption band around 400-450 nm, characteristic of the resonance of the Plasmon of silver nanoparticles. Through the scanning of the samples by means of AFM (atomic force microscopy), morphological information of the nanoparticles is obtained, from 3D topographic images of them, such as distribution, size and shape of the silver nanoparticles. Finally, its antibacterial activity was tested against the Escherichia coli strain.

scholarly journals Immobilization of Lipase on Silver Nanoparticles via Adhesive Polydopamine for Biodiesel Production

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Kanchana Dumri ◽  
Dau Hung Anh
Keyword(s):  
Silver Nanoparticles ◽  
Soybean Oil ◽  
Low Cost ◽  
Immobilized Lipase ◽  
Complex Surface ◽  
Biodiesel Production ◽  
Alternative Source ◽  
Covalent Bonds ◽  
Chromatography Analysis ◽  
Vis Spectroscopy

Biodiesel production technology is competitive in terms of low cost and alternative source of energy which should be not only sustainable but also environmentally friendly. Designing of the lipase immobilization for biodiesel production has a remarkable impact and is still challenging. In this work, biodiesel production from soybean oil was enhanced and facilitated by using a novel biocatalyst consisting of commercial lipase (EC 3.1.1.3), silver nanoparticles, and polydopamine. Silver nanoparticles (AgNPs) were synthesized with a size range of 10–20 nm. Polydopamine (PD) was delivered by the self-polymerization of dopamine in 10 mM Tris-HCl pH 8.5 and simultaneously coated the AgNPs to form a PD/AgNPs complex. Lipase was immobilized on the PD/AgNPs complex surface via covalent bonds to form a tailor-made biocatalyst consisting of immobilized lipase/PD/AgNPs complex (LPA). The formation and morphology of each composition were characterized by UV-Vis spectroscopy and scanning electron microscope (SEM). Significantly, gas chromatography analysis showed a remarkable biodiesel production yield of 95% by using the LPA complex at 40°C for 6-hours reaction time, whereas the yield was 86% when using free lyophilized lipase. The LPA complex was apparently reusable after 7 batches and the latter conversion rate of soybean oil was decreased by only 27%.

Synthesis and Characterization of Metal Nanoparticles and the Formation of Metal-Polymer Nanocomposites

2002 ◽  
Vol 740 ◽  
Author(s):  
Anshu A. Pradhan ◽  
S. Ismat Shah ◽  
Lisa Pakstis
Keyword(s):  
Thermal Conductivity ◽  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
High Surface ◽  
Average Particle Size ◽  
Nanocomposite Films ◽  
Process Conditions ◽  
Average Particle ◽  
Sem Images ◽  
Cytotoxicity Studies

ABSTRACTMetal nanoparticles are highly prone to oxidation due to their high surface energy and affinity for oxygen which can lead to the complete oxidation of the particles. Studying and utilizing the unique properties of metal nanoparticles requires minimizing their interaction with the atmosphere. We have used the co-condensation technique to synthesize suspensions of metal nanoparticles in isopropanol. The solvent protects the nanoparticles from the atmosphere and minimizes agglomeration of the nanoparticles. The particles showed a lognormal distribution and the average particle size was below 20nm. Polymer-metal nanocomposites were made by dispersing the metal nanoparticles in PMMA matrix by spin coating and solution casting. Adherent films, fibers and free standing films could be obtained by varying the process conditions. The SEM images show that the nanoparticles in the spun coated films were non-agglomerated and well dispersed over a wide area. Morphology of the spun coated films was different from the solution cast films. Electrically conducting films having interconnected silver particle network could be obtained. Cytotoxicity studies show that the silver nanoparticles and the PMMA-Ag nanocomposite films are antibacterial in nature. We have also dispersed the nanoparticle into pump oil and measured the thermal conductivity of the resultant mixture. The thermal conductivity of the oil could be increased by over 50% by adding an extremely small fraction of the silver nanoparticles.

scholarly journals ANTIMICROBIAL AND ANTICANCER ACTIVITY OF SILVER NANOPARTICLES FROM EDIBLE MUSHROOM: A REVIEW

2017 ◽  
Vol 10 (3) ◽  
pp. 37 ◽  
Author(s):  
Priyadarshni Karuppiah Chandran ◽  
Mahalingam Pambayan Ulagan
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Low Cost ◽  
Nanoparticle Synthesis ◽  
Colon Adenocarcinoma ◽  
Breast Adenocarcinoma ◽  
Metallic Silver ◽  
Liver Carcinoma ◽  
X Ray ◽  
Vis Spectroscopy

ABSTRACTBiologically inspired nanoparticle synthesis is currently a rapid expanding area of research in nanotechnology. Nanoparticle synthesis utilizing thebioresources such as plants and microbes appears to be a viable, low-cost, and eco-friendly approach. Especially mushrooms can be used for largescalesynthesis of silver nanoparticles as mushroom produces many proteins that reduce the silver nitrate during the biosynthesis. Silver nanoparticlescan be characterized using ultraviolet-visible (UV-VIS) spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction, scanning electronmicroscopy, energy dispersive X-ray, and transmission electron microscope. Silver nanoparticles possess high antibacterial activity since silver indifferent forms has been extensively used as a medicine for curing diseases and promote wound healing. Silver nanoparticles have high surfacespecific area, which will lead to excellent antimicrobial activity as compared with bulk metallic silver. Further, the silver nanoparticles show anticanceractivity against various cell lines such as human epidermoid larynx carcinoma (HEP-2), colon adenocarcinoma (HCT-116), breast adenocarcinoma(MCF-7), liver carcinoma (Hep-G2), and intestinal adenocarcinoma (Caco2) were well documented. This review intends to present green synthesis ofsilver nanoparticles and their application as antimicrobial and anticancer agents.Keywords: Silver nanoparticles, Bioresources, Mushroom, Antimicrobial activity, Anticancer property.

scholarly journals Comparative Analysis of Nanosilver Particles Synthesized by Different Approaches and Their Antimicrobial Efficacy

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hala M. Abdelmigid ◽  
Maissa M. Morsi ◽  
Nahed Ahmed Hussien ◽  
Amal Ahmed Alyamani ◽  
Noha Moslah Al Sufyani
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Fourier Transforms ◽  
Antimicrobial Effect ◽  
Trisodium Citrate ◽  
Biological Synthesis ◽  
Bacterial Strains ◽  
Fruit Peel ◽  
Vis Spectroscopy ◽  
Coffee Ground

Silver nanoparticles (AgNPs) were extensively used in different fields worldwide. There is a continued increase in their productions to fulfill various uses. Biological and chemical AgNP syntheses were the most popular mechanisms in this field. Agrowastes are rich in proteins, phenolics, and flavonoids that could act as bioreductant agents in AgNP biological synthesis. The present study was aimed at synthesizing AgNPs via chemical and biological methods using trisodium citrate, pomegranate fruit peel, and coffee ground waste extracts. Moreover, silver nanoparticles were monitored by UV-vis spectroscopy and characterized using zeta potential, size distribution mean, scanning electron microscope (SEM), X-ray diffractometer (XRD), and Fourier transforms infrared spectroscopy (FTIR). Four pathogenic bacterial strains (Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, and MRSA) were used to assess the antimicrobial effect of the synthesized AgNPs (2, 4, and 8 mg/ml). Results report the successful formation of silver nanoparticles chemically (AgNPs_Chem) and biologically by using pomegranate peel extract (AgNPs_PPE) and coffee ground waste extract (AgNPs_CE) due to the change of color to dark brown that is confirmed by UV-vis sharp absorption spectra at specific wavelengths. Characterization using SEM and XRD revealed their crystalline shape with a mean size of AgNPs _ Chem = 62.75 , AgNPs _ CE = 273.7   nm , and AgNPs _ PPE = 591.9   nm . AgNPs_Chem show higher negativity of zeta potential (−46.7 mV) than AgNPs_CE (−12.6 mV), followed by AgNPs_PPE (−7.98 mV), which had the least stability. All the synthesized AgNPs show antimicrobial potential on all selected strains. However, 8 mg/ml shows the most effective concentration and has more efficiency on K. pneumoniae than others. Overall, the results highlight that the use of agrowastes could be an ecofriendly way to synthesize AgNPs biologically that have the same antimicrobial effect as the chemically synthesized AgNPs.

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