keyword
MENU ▼
Read by QxMD icon Read
search

Colloidal silver

keyword
https://www.readbyqxmd.com/read/28415554/phytosynthesis-of-silver-nanoparticles-using-aqueous-leaf-extracts-of-lippia-citriodora-antimicrobial-larvicidal-and-photocatalytic-evaluations
#1
Elias E Elemike, Damian C Onwudiwe, Anthony C Ekennia, Richard C Ehiri, Nnaemeka J Nnaji
Nanoscience and nanotechnology represent new and enabling platforms that promise to provide broad range of novel and improved technologies for environmental, biological and other scientific applications. This study reports the synthesis of silver nanoparticles mediated by aqueous leaf extract of Lippia citriodora at two different temperatures of 50°C and 90°C. The synthesis of colloidal silver nanoparticles (AgNPs) was monitored by the use of UV-visible spectroscopy at different temperatures and time intervals...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28409425/instant-green-synthesis-of-silver-based-herbo-metallic-colloidal-nanosuspension-in-terminalia-bellirica-fruit-aqueous-extract-for-catalytic-and-antibacterial-applications
#2
Sandeep Patil, Gunjan Chaudhari, Jayasinh Paradeshi, Raghunath Mahajan, Bhushan L Chaudhari
In the present study, microwave-assisted, optimized, instant, Terminalia bellirica fruit extract-mediated green synthesis of colloidal silver nanoparticles (AgNPs) has been reported. The synthesized AgNPs were characterized by UV-Vis spectroscopy, FTIR, Zetasizer, FESEM, EDX and XRD. The characteristic surface plasmon peak of reaction mixture at 406 nm confirmed the synthesis of AgNPs. The FTIR studies confirmed phytoconstituents were responsible for the synthesis and stability of AgNPs. The FESEM, EDX and XRD analysis revealed the presence of spherical silver nanoparticles of mean diameter ≤20...
May 2017: 3 Biotech
https://www.readbyqxmd.com/read/28408822/negatively-charged-silver-nanoparticles-with-potent-antibacterial-activity-and-reduced-toxicity-for-pharmaceutical-preparations
#3
Lucia Salvioni, Elisabetta Galbiati, Veronica Collico, Giulia Alessio, Svetlana Avvakumova, Fabio Corsi, Paolo Tortora, Davide Prosperi, Miriam Colombo
BACKGROUND: The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens) and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs) are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases. METHODS: Water-soluble, negatively charged silver nanoparticles (AgNPs) were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet-visible spectroscopy...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28383922/surface-enhanced-resonance-hyper-raman-scattering-elucidates-the-molecular-orientation-of-rhodamine-6g-on-silver-colloids
#4
Hubert K Turley, Zhongwei Hu, Lasse Jensen, Jon P Camden
Herein, we utilize surface-enhanced hyper-Raman scattering (SEHRS) under resonance conditions to probe the adsorbate geometry of rhodamine 6G (R6G) on silver colloids. Our results show resonance SEHRS is highly sensitive to molecular orientation due to non-Condon effects, which do not appear in its linear counterpart surface-enhanced Raman scattering. Comparisons between simulated and measured SEHRS spectra reveal R6G adsorbs mostly perpendicular to the nanoparticle surface along the ethylamine groups with the xanthene ring oriented edgewise...
April 20, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28381077/the-effect-of-silver-and-copper-nanoparticles-on-the-wheat-pseudocercosporella-herpotrichoides-pathosystem
#5
V N Belava, O O Panyuta, G M Yakovleva, Y M Pysmenna, M V Volkogon
The paper covers the study of the effects of silver (Ag) and copper (Cu) nanoparticles on wheat-Pseudocercosporella herpotrichoides pathosystem in general and, separately, on their interaction both with the plant and with the pathogen. Plants, treated with nonionic colloidal solutions of biogenic metal nanoparticles of Ag and Cu, have taken seed treatment as stress and have demonstrated the same changes in the dynamic patterns of thiobarbituric acid reactive substances (TBARS) content as a seedling infection or in its combination with a nanoparticle treatment...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28379105/the-ability-of-a-colloidal-silver-gel-wound-dressing-to-kill-bacteria-in-vitro-and-in-vivo
#6
P L Tran, E Huynh, A N Hamood, A de Souza, D Mehta, K W Moeller, C D Moeller, M Morgan, T W Reid
OBJECTIVE: Inhibiting bacterial biofilms is of major significance for proper wound healing. The choice of the dressing material plays a key role, as bacteria can live in dressings and keep reinfecting the wound. This study examines the effectiveness of a colloidal silver gel (Ag-gel) wound dressing in inhibiting the growth of bacteria in a mouse wound model. METHOD: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and two different meticillin-resistant Staphylococcus aureus (MRSA) strains were examined...
April 1, 2017: Journal of Wound Care
https://www.readbyqxmd.com/read/28335201/size-and-shape-dependent-antibacterial-studies-of-silver-nanoparticles-synthesized-by-wet-chemical-routes
#7
Muhammad Akram Raza, Zakia Kanwal, Anum Rauf, Anjum Nasim Sabri, Saira Riaz, Shahzad Naseem
Silver nanoparticles (AgNPs) of different shapes and sizes were prepared by solution-based chemical reduction routes. Silver nitrate was used as a precursor, tri-sodium citrate (TSC) and sodium borohydride as reducing agents, while polyvinylpyrrolidone (PVP) was used as a stabilizing agent. The morphology, size, and structural properties of obtained nanoparticles were characterized by scanning electron microscopy (SEM), UV-visible spectroscopy (UV-VIS), and X-ray diffraction (XRD) techniques. Spherical AgNPs, as depicted by SEM, were found to have diameters in the range of 15 to 90 nm while lengths of the edges of the triangular particles were about 150 nm...
April 15, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28329568/localized-cutaneous-argyria-report-of-two-patients-and-literature-review
#8
Bryce David Beutler, Robert A Lee, Philip R Cohen
BackgroundLocalized cutaneous argyria is a rare skin condition caused by direct contact with silver or silver particles. It presents as asymptomatic gray or blue-gray macules that appear similar to blue nevi. Histologic features include brown-colored or black-colored silver granules in the basement membrane and dermis, most commonly surrounding eccrine glands, elastic fibers, and collagen fibrils. The condition is most frequently observed in individuals who are regularly exposed to small silver particles, such as silversmiths and welders...
November 15, 2016: Dermatology Online Journal
https://www.readbyqxmd.com/read/28235364/synthesis-and-examination-of-nanocomposites-based-on-poly-2-hydroxyethyl-methacrylate-for-medicinal-use
#9
Olena S Kukolevska, Igor I Gerashchenko, Mykola V Borysenko, Evgenii M Pakhlov, Michal Machovsky, Tetyana I Yushchenko
Preparation of poly(2-hydroxyethyl methacrylate) (PHEMA) based nanocomposites using different approaches such as synthesis with water as the porogen, filling of polymer matrix by silica and formation of interpenetrating polymer networks with polyurethane was demonstrated. Incorporation of various biologically active compounds (BAC) such as metronidazole, decamethoxin, zinc sulphate, silver nitrate or amino acids glycine and tryptophan into nanocomposites was achieved. BAC were introduced into the polymer matrix either (1) directly, or (2) with a solution of colloidal silica, or (3) through immobilization on silica (sol-densil)...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28217797/poly-vinyl-alcohol-as-a-water-protecting-agent-for-silver-nanoparticles-the-role-of-polymer-size-and-structure
#10
Alexander Kyrychenko, Dmitry A Pasko, Oleg N Kalugin
Chemical modification of silver nanoparticles (AgNPs) with a stabilizing agent, such as poly(vinyl alcohol) (PVA), plays an important role in shape-controlled seeded-growth and colloidal stability. However, theoretical aspects of the stabilizing mechanism of PVA are still poorly understood. To gain a better understanding of the role of PVA in water protecting effects for silver nanoparticles, we developed an atomistic model of a AgNP grafted with single-chain PVA of various lengths. Our model, designed for classical molecular dynamics (MD) simulations, approximates the AgNP as a quasi-spherical silver nanocrystal with 3...
February 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28199144/attachment-of-13-types-of-foodborne-bacteria-to-jalape%C3%A3-o-and-serrano-peppers-and-antibacterial-effect-of-roselle-calyx-extracts-sodium-hypochlorite-colloidal-silver-and-acetic-acid-against-these-foodborne-bacteria-on-peppers
#11
Esmeralda Rangel-Vargas, Carlos A Gómez-Aldapa, Reyna N Falfan-Cortes, María L Rodríguez-Marín, Angélica Godínez-Oviedo, Otilio A Acevedo-Sandoval, Javier Castro-Rosas
Chili peppers are a very important crop in Mexico. However, these peppers have been associated with Salmonella infection outbreaks in the United States, and Salmonella and diarrheagenic Escherichia coli pathotypes have been isolated from jalapeño and serrano peppers in Mexico. To decrease microbial contamination of fruits and vegetables, chemical agents are commonly used; however, chemical agents used to eliminate pathogenic bacteria on vegetables have a limited antimicrobial effect. Roselle ( Hibiscus sabdariffa ) calyces have been reported to have an antimicrobial effect on pathogenic bacteria...
February 15, 2017: Journal of Food Protection
https://www.readbyqxmd.com/read/28198355/in-situ-spectroscopy-of-ligand-exchange-reactions-at-the-surface-of-colloidal-gold-and-silver-nanoparticles
#12
Rebecca Dinkel, Wolfgang Peukert, Björn Braunschweig
Gold and silver nanoparticles with their tunable optical and electronic properties are of great interest for a wide range of applications. Often the ligands at the surface of the nanoparticles have to be exchanged in a second step after particle formation in order to obtain a desired surface functionalization. For many techniques, this process is not accessible in situ. In this review, we present second-harmonic scattering (SHS) as an inherently surface sensitive and label-free optical technique to probe the ligand exchange at the surface of colloidal gold and silver nanoparticles in situ and in real time...
February 15, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28192905/extracting-metallic-nanoparticles-from-soils-for-quantitative-analysis-method-development-using-engineered-silver-nanoparticles-and-sp-icp-ms
#13
D M Schwertfeger, Jessica R Velicogna, Alexander H Jesmer, Selin Saatcioglu, Heather McShane, Richard P Scroggins, Juliska I Princz
The lack of an efficient and standardized method to disperse soil particles and quantitatively subsample the nanoparticulate fraction for characterization analyses is hindering progress in assessing the fate and toxicity of metallic engineered nanomaterials in the soil environment. This study investigates various soil extraction and extract preparation techniques for their ability to remove nanoparticulate Ag from a field soil amended with biosolids contaminated with engineered silver nanoparticles (AgNPs), while presenting a suitable suspension for quantitative single-particle inductively coupled plasma mass spectroscopy (SP-ICP-MS) analysis...
January 30, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28191921/design-of-hybrid-nanostructural-arrays-to-manipulate-sers-active-substrates-by-nanosphere-lithography
#14
Xiaoyu Zhao, Jiahong Wen, Mengning Zhang, Dunhui Wang, Yaxin Wang, Lei Chen, Yongjun Zhang, Jinghai Yang, Youwei Du
An easy-handling and low-cost method is utilized to controllably fabricate nanopattern arrays as the surface-enhanced Raman scattering (SERS) active substrates with high density of SERS-active areas (hot spots). A hybrid silver array of nanocaps and nanotriangles are prepared by combining magnetron sputtering and plasma etching. By adjusting the etching time of polystyrene (PS) colloid spheres array in silver nanobowls, the morphology of the arrays can be easily manipulated to control the formation and distribution of hot spots...
March 1, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28186767/size-control-of-silver-core-silica-shell-nanoparticles-fabricated-by-laser-ablation-assisted-chemical-reduction
#15
Victor A Ermakov, Ernesto Jimenez-Villar, José Maria Clemente da Silva Filho, Emre Yassitepe, Naga Vishnu Vardhan Mogili, Fernando Iikawa, Gilberto Fernandes de Sá, Carlos Lenz Cesar, Francisco Chagas Marques
Aqueous colloidal silver nanoparticles have substantial potential in biological application as markers and antibacterial agents and in surface-enhanced Raman spectroscopy applications. A simple method of fabrication and encapsulation into an inert shell is of great importance today to make their use ubiquitous. Here we show that colloids of silver-core/silica-shell nanoparticles can be easily fabricated by a laser-ablation-assisted chemical reduction method and their sizes can be tuned in the range of 2.5 to 6...
February 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28177604/green-in-situ-synthesis-of-clean-3d-chestnutlike-ag-wo3-x-nanostructures-for-highly-efficient-recyclable-and-sensitive-sers-sensing
#16
Jian Huang, Dayan Ma, Feng Chen, Dongzhen Chen, Min Bai, Kewei Xu, Yongxi Zhao
Surface-enhanced Raman scattering (SERS) has proven to be an effective technique for identifying and providing fingerprint structural information on various analytes in low concentration. However, this analytical technique has been plagued by the ubiquitous presence of organic contaminants on roughened SERS substrate surfaces, which not only often result in poorer detection sensitivity but also significantly affect the reproducibility and accuracy of SERS analysis. Herein, we developed a clean, stable, and recyclable three-dimensional (3D) chestnutlike Ag/WO3-x (0 < x < 0...
March 1, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28177254/experimental-and-numerical-investigations-of-silver-nanoparticle-transport-under-variable-flow-and-ionic-strength-in-soil
#17
Joanna Makselon, Dan Zhou, Irina Engelhardt, Diederik Jacques, Erwin Klumpp
Unsaturated column experiments were conducted with an undisturbed loamy sand soil to investigate the influence of flow interruption (FI) and ionic strength (IS) on the transport and retention of surfactant-stabilized silver nanoparticles (AgNP) and the results were compared to those obtained under continuous flow conditions. AgNP concentrations for breakthrough curves (BTCs) and retention profiles (RPs) were analyzed by ICP-MS. Experimental results were simulated by the numerical code HP1 (Hydrus-PhreeqC) with the DLVO theory, extended colloid filtration theory and colloid release model...
February 8, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28159292/determination-of-histamine-in-fish-by-surface-enhanced-raman-spectroscopy-using-silver-colloid-sers-substrates
#18
Tibor Janči, Davor Valinger, Jasenka Gajdoš Kljusurić, Lara Mikac, Sanja Vidaček, Mile Ivanda
This study was focused on development of a rapid and sensitive method for histamine determination in fish based on Surface Enhanced Raman Spectroscopy (SERS) using simple and widely available silver colloid SERS substrate. Extraction of histamine with 0.4M perchloric acid and purification with 1-butanol significantly shortened sample preparation (30min) and provided clear SERS spectra with characteristic Raman bands of histamine. Principal component analysis effectively distinguished SERS spectra of fish samples with different histamine content...
June 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28159107/chlorine-triggered-de-alloying-of-auag-carbon-nanodots-towards-fabrication-of-a-dual-signalling-assay-combining-the-plasmonic-property-of-bimetallic-alloy-nanoparticles-and-photoluminescence-of-carbon-nanodots
#19
Zahra Mohammadpour, Afsaneh Safavi, Seyyed Hossein Abdollahi
Integration of Au-Ag alloy and fluorescent carbon nanodots (C-dots) into a single platform resulted in a new dual sensing assay for chlorine. Selective etching of Ag from AuAg@C-dots was transformed into: (i) colorimetric signal by surface plasmon resonance (SPR) tuning of the alloy and (ii) fluorimetric signal by perturbation of fluorescence energy transfer between C-dots and alloy nanoparticles. Fast oxidizing of silver atoms incorporated in the bimetallic structure induced by chlorine resulted in selective de-alloying of bimetallic hybrid nanoparticles and an intense visible change of the colloidal dispersion color...
March 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28126610/vortex-assisted-layer-by-layer-assembly-of-silver-nanowire-thin-films-for-flexible-and-transparent-conductive-electrodes
#20
Changho Kim, Hyojin An, Arum Jung, Bongjun Yeom
Silver nanowires (AgNWs) have drawn much attention as potential candidates to replace conventional transparent conductive materials such as indium tin oxide (ITO). AgNWs have advantages over ITO with respect to cost and ease of fabrication, and can be used in flexible electrodes. However, the preparation of homogeneous films from the AgNW colloidal suspension is still a challenge mainly because of the coagulation and sedimentation of AgNWs in aqueous media. In this study, uniform transparent conductive films were prepared by using AgNWs paired with poly(allylamine hydrochloride) (PAH) via the vortex-assisted layer-by-layer (VA-LbL) assembly method...
January 17, 2017: Journal of Colloid and Interface Science
keyword
keyword
77920
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"