scholarly journals Study of Role of Silver Nanoparticles on Spectroscopic Properties of a KetocyanineDye

2016 ◽  
Vol 15 (1) ◽  
pp. 1-16
Author(s):  
Thipperudrappa J
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Spectroscopic Properties ◽  
Chemical Reduction Method ◽  
Quenching Rate ◽  
Number Of Binding Sites ◽  
Volmer Plot ◽  
Quenching Mechanisms ◽  
Static Part

The role of silver nanoparticles on spectroscopic properties of the ketocyaninedye 2,5-di[(E)-1-(4- dimethylaminophenyl) methylidine]-1-cyclopentanone (2,5-DMAPMC) has been investigated using absorption and fluorescence spectroscopy. Silver nanoparticles are synthesized by chemical reduction method and estimated size from SEM measurements is 22 nm. The changes in absorption spectrum of dye in the presence of silver nanoparticles suggest the possible interaction with silver nanoparticles. The Stern-Volmer plot of fluorescence quenching is found to be nonlinear showing positive deviation. The magnitude of quenching rate parameter and fluorescence lifetime measurements indicates the presence of both collisional and static quenching mechanisms. The binding constant and number of binding sites for static part of the quenching have been

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

Modification of Spectral Behavior of Ketocyanine Dyes by Silver Nanoparticles of Different Sizes

2019 ◽  
Vol 18 (02) ◽  
pp. 1850022
Author(s):  
J. Thipperudrappa ◽  
U. P. Raghavendra ◽  
H. R. Deepa ◽  
Mahantesha Basanagouda
Keyword(s):  
Silver Nanoparticles ◽  
Fluorescence Quenching ◽  
Dye Molecules ◽  
Rate Parameter ◽  
Quenching Rate ◽  
Spectral Behavior ◽  
Spectral Changes ◽  
Increase With Increase ◽  
Quenching Mechanisms ◽  
Ketocyanine Dyes

The spectral behavior of two ketocyanine dyes 2,5-di[(E)-1-(4-dimethylaminophenyl) methylidine]-1-cyclopentanone(2,5-DMAPMC) and 2,5-di[(E)-1-(4-diethylaminophenyl) methylidine]-1-cyclopentanone (2,5-DEAPMC) is investigated in the presence of silver nanoparticles (AgNPs) of sizes 32[Formula: see text]nm, 52[Formula: see text]nm and 60[Formula: see text]nm using absorption and fluorescence spectroscopy. The absorption spectral changes of dyes with the addition of AgNPs of different sizes suggest their possible interaction with AgNPs. Fluorescence quenching has been observed for both the dyes with the addition of AgNPs of all the sizes. The possible quenching mechanisms including energy transfer and electron transfer are discussed. The fluorescence quenching rate parameter is found to increase with increase in the size of AgNPs and is explained based on the varying ability of silver AgNPs of different sizes to accommodate dye molecules. The effect of functional groups on quenching rate parameters is also discussed.

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.

Electrical Properties of Silver Paste Prepared from Nanoparticles and Lead-Free Frit

2007 ◽  
Vol 7 (11) ◽  
pp. 3917-3919 ◽  
Author(s):  
Sung Hyun Park ◽  
Dong Seok Seo ◽  
Jong Kook Lee
Keyword(s):  
Silver Nanoparticles ◽  
Electrical Properties ◽  
Screen Printing ◽  
Chemical Reduction ◽  
Silver Powder ◽  
Average Particle Size ◽  
Average Particle ◽  
Chemical Reduction Method ◽  
Silver Paste ◽  
Thermal And Electrical Properties

Recently, PbO containing glass systems in commercial silver paste have been used due to their low glass transition temperature, good thermal and electrical properties. However, PbO is a hazardous material to both health and the environment. In this study, Pb-free silver paste was prepared by mixing commercial silver powder and silver nanoparticles. The commercial powder has an average particle size of 1.6 μm. The silver nanoparticles with particles size of 20–50 nm were synthesized by a chemical reduction method using surfactant. Pb-free frit was added into the mixed silver powder as the amounts of 3, 6 and 9 wt%. Using the obtained paste, thick films were fabricated by a screen printing on alumina substrate and the films were fired at temperature from 400 to 550 °C. The films had thickness of 6–11 μm and sheet resistivity of about 4–11 μΩ cm.

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.

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.

Nanoscale water soluble self-assembled zero-valent iron: role of stabilizers in their morphology

RSC Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 7267-7278 ◽  
Author(s):  
Zaheer Khan ◽  
Shaeel Ahmed AL-Thabaiti ◽  
Shokit Hussain
Keyword(s):  
Aqueous Solution ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Zero Valent Iron ◽  
Nano Composites ◽  
Chemical Reduction Method ◽  
One Pot ◽  
Self Assembled

Self-assembled water soluble sheet-like zero-valent iron nano-composites were prepared using a simple one-pot chemical reduction method in an aqueous solution of FeCl3and NaBH4both with and without CTAB and SDS.

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