scholarly journals Nanosilver against fungi. Silver nanoparticles as an effective biocidal factor.

1970 ◽  
Vol 60 (4) ◽  
Author(s):  
Jolanta Pulit ◽  
Marcin Banach ◽  
Renata Szczygłowska ◽  
Mirosław Bryk
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Reduction Method ◽  
Ph Value ◽  
Chemical Reduction ◽  
Silver Ions ◽  
Chemical Reduction Method ◽  
Stabilizing Agents ◽  
Independent Variables

The work presents a method of obtaining an aqueous raspberry extract as well as its physicochemical and analytical characteristics. The paper also contains a description of the method of preparation of nanosilver suspensions based on this extract. The raspberry extract served as a source of phenolic compounds which acted as both reducing and stabilizing agents. Suspensions of silver nanoparticles were obtained with the use of chemical reduction method. The silver ions concentration, pH value and temperature of samples incubation were independent variables. The next step of the research was to measure the antifungal activity of the received silver nanoparticles as well as to perform a mycological efficacy resistance analysis of the tested preparations in relation to different concentrations of nanostructured silver. Tests were conducted in compliance with the Eucast guidelines. The results of microbiological study of (the samples') biocidal effect against Cladosporium cladosporoides and Aspergillus niger are described. It was found that using nanosilver suspension at the concentration of 50 ppm inhibited the growth of Cladosporium cladosporoides and Aspergillus niger by 90% and 70%, respectively.

scholarly journals Synthesis of Highly Concentrated Suspensions of Silver Nanoparticles by Two Versions of the Chemical Reduction Method

2018 ◽  
Vol 2 (1) ◽  
pp. 3 ◽  
Author(s):  
Miguel Gakiya-Teruya ◽  
Luis Palomino-Marcelo ◽  
Juan Rodriguez-Reyes
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Silver Ions ◽  
Chemical Reduction Method ◽  
Concentrated Suspensions ◽  
Regular Method ◽  
Alternative Method ◽  
Study Protocols

In spite of the widespread use of the chemical reduction method to obtain silver nanoparticles, the nanoparticle yield is often low due to a required addition of small volumes of diluted metal ions to a solution containing a reducer. Higher yields can be obtained following an alternative method, in which the reducer is added to a greater volume of silver ions in the solution. In this study, protocols for both methods are detailed and compared, using characterization tools such as UV-vis spectrometry, dynamic light scattering (DLS), and zeta potential measurements. By using this alternative method, the amount of silver in the solution is three times greater, and nanoparticles with a narrower size distribution are formed (between 6 and 70 nm in size). In contrast, the regular method produces particles of 3 and 100 nm. Zeta potential measurements indicate that the nanoparticles synthesized with the alternative method will be more stable than those from the regular method.

scholarly journals Raspberry Extract as Both a Stabilizer and a Reducing Agent in Environmentally Friendly Process of Receiving Colloidal Silver

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Jolanta Pulit ◽  
Marcin Banach ◽  
Michał Zielina ◽  
Barbara Laskowska ◽  
Kamil Kurleto
Keyword(s):  
Reduction Method ◽  
Chemical Reduction ◽  
Silver Ions ◽  
Aqueous Environment ◽  
Suspension Stability ◽  
Chemical Reduction Method ◽  
Stabilizing Agents ◽  
Dynamic Light Scattering Technique ◽  
Environmentally Friendly Process ◽  
Light Scattering Technique

An ecofriendly method of nanosilver obtaining has been studied. The process involves the chemical reduction method carried out in aqueous environment. Silver nitrate (V) was applied as a silver ions source. Raspberry extract was used as a natural source of both reducing and stabilizing agents. The total amount of phenolic compounds was determined by the Folin-Ciocalteu method. Obtained nanoparticles were analyzed by the dynamic light scattering technique so as to determine the particles size and suspension stability which was characterized by an electrokinetic potential. The results confirmed that the size of some nanoparticles was under 100 nm.

Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

2011 ◽  
Vol 4 (3) ◽  
pp. 1491-1496
Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Therapeutic Potential ◽  
Chemical Reduction ◽  
Ultrasonic Field ◽  
Great Promise ◽  
Chemical Reduction Method ◽  
E Coli

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles. 

scholarly journals Using a non-reducing sugar in the green synthesis of gold and silver nanoparticles by the chemical reduction method

DYNA ◽  
2018 ◽  
Vol 85 (206) ◽  
pp. 69-78 ◽  
Author(s):  
Wilson Agudelo ◽  
Yuliet Montoya ◽  
John Bustamante
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Reducing Sugar ◽  
Chemical Reduction Method ◽  
Gold And Silver Nanoparticles ◽  
Uv Visible

El uso de compuestos químicos más biocompatibles y renovables para la obtención de nanopartículas metálicas con propiedades y características deseadas, se convierte en una ruta alternativa para la reducción de riesgos ambientales y del grado de incompatibilidad de estas estructuras al interactuar con modelos biológicos para su posible aplicación en el área de la salud. El propósito de este trabajo se centró en el uso de sacarosa, como agente reductor de nanopartículas de oro y plata al emplear diferentes volúmenes de hidróxido de sodio. Las nanopartículas obtenidas fueron caracterizadas mediante espectrometría UV-visible, microscopía electrónica de transmisión TEM y espectroscopia infrarroja por transformada de Fourier FTIR, la cual permitió determinar los plasmones de resonancia superficial, tamaños de partícula experimentales y teóricos, morfología y cambios estructurales en el agente reductor, así como la influencia del hidróxido de sodio en el proceso de síntesis. Los resultados obtenidos confirman la formación de nanopartículas de oro y plata mediante la previa formación de azúcares reductores. Así mismo, la oxidación del grupo funcional de la glucosa a sales de ácido carboxílico.

Preparation and characterization of silver nanoparticles by chemical reduction method

2011 ◽  
Vol 82 (2) ◽  
pp. 513-517 ◽  
Author(s):  
Zaheer Khan ◽  
Shaeel Ahmed Al-Thabaiti ◽  
Abdullah Yousif Obaid ◽  
A.O. Al-Youbi
Keyword(s):  
Silver Nanoparticles ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Chemical Reduction Method

scholarly journals Interaction of Pulses of Different Duration with Chemically Prepared Silver Nanoparticles: Analysis of Optical Nonlinearities

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ke Zhang ◽  
Rashid A. Ganeev ◽  
Konda Srinivasa Rao ◽  
Sandeep Kumar Maurya ◽  
Ganjaboy S. Boltaev ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Nonlinear Refraction ◽  
Optical Nonlinearities ◽  
Chemical Reduction Method ◽  
Ag Nps ◽  
Picosecond Pulses

The nonlinear optical properties of the aqueous solutions of silver nanoparticles (Ag NPs) prepared by chemical reduction method are analyzed using femtosecond and picosecond pulses at different wavelengths. In the case of 800 and 400 nm, the growths of nonlinear absorption and nonlinear refraction with the increase of Ag NP concentration, as well as a change at the signs of nonlinear optical processes, are determined. The nonlinear absorption coefficient and nonlinear refractive index of Ag NP solutions measured using picosecond pulses were a few orders of magnitude larger than those in the case of femtosecond probe pulses. We also demonstrate the optical limiting properties of Ag NPs using 800 nm, 60 fs pulses.

Effect of Surfactant on the Morphology of Silver Nanoparticles

2007 ◽  
Vol 124-126 ◽  
pp. 1205-1208 ◽  
Author(s):  
Keun Ju Park ◽  
Dong Seok Seo ◽  
Woo Yang Jang ◽  
Jong Kook Lee
Keyword(s):  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Low Temperature ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Sodium Dodecyl ◽  
Capping Agent ◽  
Silver Particles ◽  
Chemical Reduction Method ◽  
20 Nm

Nano-sized silver particles are considered to apply a silver paste for electrode because of its high conductivity on sintering at low temperature. In this study, silver nanoparticles as seeds were prepared by chemical reduction method with capping agent. Silver particles were prepared using SDS (Sodium dodecyl sulfate) as a surfactant and silver nanoparticles as seeds and reacted with ascorbic acid as a reduction agent. The silver seeds with 10-20 nm in size with uniform distribution were formed and the size and shape of silver particles were strongly dependent on the concentration of surfactant.

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