scholarly journals Effect of Silver Nanoparticles on Fluorescence Intensity of Fluoreseina Dye Mixed in One Solution

2021 ◽  
Vol 19 (51) ◽  
pp. 54-63
Author(s):  
Ruwaida Tahseen Shbeeb ◽  
Sarmed S. Mahdi ◽  
Sabreen A. Khalaf
Keyword(s):  
Silver Nanoparticles ◽  
Fluorescence Intensity ◽  
Chemical Reduction ◽  
Metal Nanoparticle ◽  
Metal Nanostructures ◽  
Enhanced Fluorescence ◽  
Ag Nps ◽  
Study Results ◽  
Layer Coating ◽  
Dye Solutions

Metal enhanced fluorescence (MEF) is an unequaled phenomenon of metal nanoparticle surface plasmons, when light interacts with the metal nanostructures (silver nanoparticles) which result electromagnetic fields to promote the sensitivity of fluorescence. This work endeavor to study the influence of silver nanoparticles on fluorescence intensity of Fluoreseina dye by employment mixture solution with different mixing ratio. Silver nanoparticles had been manufactured by the chemical reduction method so that Ag NP layer coating had been done by hot rotation liquid method. The optical properties of the prepared samples (mixture solution of Fluoreseina dye solutions and colloidal solution with 5 minutes prepared of Ag NPs) tested by using UV-VIS absorption and Fluorescence spectrophotometer. by using AFM, SEM testes, the structure of silver nanoparticles had been estimated. the result of this work showed that adding Ag NPs colloidal to Fluoreseina dye solution help get a significant increase in the fluorescence intensity of this dye. this study results show that its significant to recent related studies in MEF.

scholarly journals Enhanced fluorescence properties of terbium complex/poly-l-lactic acid superfine fibers sensitized by the LSPR effect of silver nanoparticles

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19808-19814 ◽  
Author(s):  
Shipeng Wen ◽  
Guiming Zhang ◽  
Rong Zhang ◽  
Liqun Zhang ◽  
Li Liu
Keyword(s):  
Silver Nanoparticles ◽  
Lactic Acid ◽  
Quantum Efficiency ◽  
Fluorescence Intensity ◽  
Fluorescence Properties ◽  
Composite Fibers ◽  
Enhanced Fluorescence ◽  
Terbium Complex ◽  
Ag Nps ◽  
Lspr Effect

Due to the LSPR effect of Ag-NPs, the fluorescence intensity, quantum efficiency of Tb-complex in the composite fibers were improved.

scholarly journals Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi
Keyword(s):  
Silver Nanoparticles ◽  
Irradiation Time ◽  
Chemical Reduction ◽  
Size Control ◽  
Reduction Process ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Transmission Electron ◽  
Origanum Majorana

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

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.

A nano silver-xerogel (Ag nps@modified TEOS) as a newly developed nanocatalyst in the synthesis of benzopyranopyrimidines (with secondary and primary amines) and gem-bisamides

2017 ◽  
Vol 46 (21) ◽  
pp. 7039-7050 ◽  
Author(s):  
Gurpreet Kour ◽  
Monika Gupta
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Primary Amines ◽  
Ag Nps ◽  
Nano Silver ◽  
Reduction Approach

Silver nanoparticles have been prepared from a chemical reduction approach and supported on modified TEOS (tetraethylorthosilicate) xerogel to be studied as a nanocatalyst.

scholarly journals Fabrication, Characterization, and Antibacterial Properties of Electrospun Membrane Composed of Gum Karaya, Polyvinyl Alcohol, and Silver Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Vinod Vellora Thekkae Padil ◽  
Nhung H. A. Nguyen ◽  
Alena Ševců ◽  
Miroslav Černík
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Food Packaging ◽  
Chemical Reduction ◽  
Antibacterial Properties ◽  
Hydroxyl Groups ◽  
Ag Nps ◽  
Gum Karaya ◽  
Nanofiber Membranes

Gum karaya (GK), a natural hydrocolloid, was mixed with polyvinyl alcohol (PVA) at different weight ratios and electrospun to produce PVA/GK nanofibers. An 80 : 20 PVA/GK ratio produced the most suitable nanofiber for further testing. Silver nanoparticles (Ag-NPs) were synthesised through chemical reduction of AgNO3(at different concentrations) in the PVA/GK solution, the GK hydroxyl groups being oxidised to carbonyl groups, and Ag+cations reduced to metallic Ag-NPs. These PVA/GK/Ag solutions were then electrospun to produce nanofiber membranes containing Ag-NPs (Ag-MEMs). Membrane morphology and other characteristics were analysed using scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, and UV-Vis and ATR-FTIR spectroscopy. The antibacterial activity of the Ag-NP solution and Ag-MEM was then investigated against Gram-negativeEscherichia coliandPseudomonas aeruginosaand Gram-positiveStaphylococcus aureus. Our results show that electrospun nanofiber membranes based on natural hydrocolloid, synthetic polymer, and Ag-NPs have many potential uses in medical applications, food packaging, and water treatment.

scholarly journals Subinhibitory concentrations of silver nanoparticles and silver nitrate on the adaptative and cross-resistance to antibiotics on bovine mastitis pathogens

2021 ◽  
Vol 51 (12) ◽  
Author(s):  
Patrícia Érica Fernandes ◽  
Roberta Barbosa Teodoro Alves ◽  
Natan de Jesus Pimentel-Filho ◽  
João Paulo Natalino de Sá ◽  
Hilário Cuquetto Mantovani ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Chemical Reduction ◽  
Bovine Mastitis ◽  
Cross Resistance ◽  
Ag Nps ◽  
Adaptive Resistance ◽  
Subinhibitory Concentrations ◽  
Mastitis Pathogens ◽  
Sensitivity Profile

ABSTRACT: Biocides and/or antibiotics used in subinhibitory concentrations can promote the development of adaptive resistance or even cross-resistance in microorganisms. However, studies on these responses following silver treatments are scarce in the literature. Silver-based compounds, including silver nanoparticles (Ag-NPs), can be an alternative in the prevention and treatment of bovine mastitis. Thus, this research evaluated the effect of subinhibitory dosages of Ag-NPs and Ag+ ions from silver nitrate (AgNO3) on Staphylococcus aureus and Escherichia coli isolated from milk of cows with mastitis. Ag-NPs were synthesized by chemical reduction using AgNO3 and sodium citrate and the minimum inhibitory concentration (MIC) of Ag-NPs and Ag+ ions on the mastitis pathogens were determined. Isolates were exposed to subinhibitory concentrations of Ag-NPs or AgNO3 for 10 consecutive days to verify the development of adaptive resistance evaluated by changes in the MIC values. The development of cross-resistance with antibiotics was also studied, being verified by comparing the sensitivity profile of treated cells with non-treated cells. AgNO3 was more effective against all isolates. There was no change in the MIC values or in the antibiotic sensitivity profile for both bacteria following consecutive exposure to subinhibitory dosages of Ag-NPs or AgNO3, indicating that silver was not able to select adaptive resistance or cross resistance to the tested antibiotics. The potential of silver presented by these results is favorable to the continuity of studies aiming to elaborate silver-based therapies for the treatment of bovine mastitis.

scholarly journals Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5168
Author(s):  
Elżbieta Szczepańska ◽  
Anna Synak ◽  
Piotr Bojarski ◽  
Paweł Niedziałkowski ◽  
Anna Wcisło ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Fluorescence Intensity ◽  
Control Sample ◽  
Core Shell ◽  
Enhanced Fluorescence ◽  
Shell Nanostructures ◽  
Dansyl Group ◽  
Transmission Electron ◽  
Silver Mirror ◽  
Water Wettability

The present work describes synthesis, characterization, and use of a new dansyl-labelled Ag@SiO2 nanocomposite as an element of a new plasmonic platform to enhance the fluorescence intensity. Keeping in mind that typical surface plasmon resonance (SPR) characteristics of silver nanoparticles coincide well enough with the absorption of dansyl molecules, we used them to build the core of the nanocomposite. Moreover, we utilized 10 nm amino-functionalized silica shell as a separator between silver nanoparticles and the dansyl dye to prevent the dye-to-metal energy transfer. The dansyl group was incorporated into Ag@SiO2 core-shell nanostructures by the reaction of aminopropyltrimethoxysilane with dansyl chloride and we characterized the new dansyl-labelled Ag@SiO2 nanocomposite using transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). Additionally, water wettability measurements (WWM) were carried out to assess the hydrophobicity and hydrophilicity of the studied surface. We found that the nanocomposite deposited on a semitransparent silver mirror strongly increased the fluorescence intensity of dansyl dye (about 87-fold) compared with the control sample on the glass, proving that the system is a perfect candidate for a sensitive plasmonic platform.

scholarly journals Photo-induced chemical reduction of silver bromide to silver nanoparticles

2011 ◽  
Vol 9 (6) ◽  
pp. 982-989 ◽  
Author(s):  
Agnieszka Król-Gracz ◽  
Ewa Michalak ◽  
Piotr Nowak ◽  
Agnieszka Dyonizy
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Silver Bromide ◽  
Molar Ratio ◽  
Efficient Production ◽  
Ag Nps ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Nanoparticle Suspensions ◽  
Actinic Radiation

AbstractThis paper discusses the experimental results of the production of nanocolloidal silver using photoreduction method. Ultrafine crystalline gelatine-stabilised aqueous suspensions of silver bromide were used as a substrate for the synthesis of silver nanoparticles (Ag NPs). The influences of the reductant to substrate molar ratio, the medium’s pH, the type of the source of actinic radiation and the time of exposure to the efficient production of the Ag NPs were studied. A typical reaction was suggested, which involves the photo-induced reduction of silver bromide nanocrystals in the presence of ascorbic acid under specified physicochemical conditions. The properties of resultant silver particles were examined using UV-Vis spectroscopy and Dynamic Light Scattering (DLS). In addition, Transmission Electron Microscopy (TEM) was used for imaging the silver nanoparticle suspensions.

Synthesis of Silver Nanoparticles with Potential Antifungical Activity for Bamboo Treatment

2015 ◽  
Vol 668 ◽  
pp. 86-91 ◽  
Author(s):  
Omar Pandoli ◽  
Fatima Ventura Pereira-Meirelles ◽  
Eric Monteiro Lobo Lobo Luz ◽  
Aline Assumpção ◽  
Raquel dos Santos Martins ◽  
...  
Keyword(s):  
Chemical Reduction ◽  
Sol Gel ◽  
Organic Ligand ◽  
Trisodium Citrate ◽  
Metal Nanoparticle ◽  
Flow Mode ◽  
Ag Nps ◽  
Easy Method ◽  
Nanostructural Material ◽  
Potassium Tartrate

To increase the durability of bamboo it is important to find an easy method to fill the micro and meso structure of the biological matrix using a nanostructural material with an anti-fungical activity. A colloidal solution of silver nanoparticle (Ag-NPs) is a dispersion of metal nanoparticle in water with a diameter between 5-100 nm. Even if the biological mechanism is not completly understood yet, Ag-NPs show a satisfactory bactericidal and antifungical activity. We present a simple and rapid production of Ag-NPs made by a sol-gel synthesis in flow mode by means of microreactor tecnology through a chemical reduction of AgNO3 with NaBH4 in presence of two different organic ligands: sodium/potassium tartrate and trisodium citrate. The synthesis of Ag-NPs in continuous flow compared to the batch technique allowed to reduce the time of synthesis, facilitating the reproducibility of the process and consequently obtaining NPs with more uniform physical and chemical characteristics. The microorganisms of the genus Aspergillus were used for the microbiological tests. The effect of different Ag-NPs on microbial growth was observed daily. In particular, it was shown that the response of the fungus is inversely proportional to the size of the nanoparticles, cell growth is disrupt depending on the proportion between silver and organic ligand and microbialstatic effect, especially in relation to sporulation stage was also observed.

scholarly journals Artificial Intelligence in Numerical Modeling of Silver Nanoparticles Prepared in Montmorillonite Interlayer Space

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Parvaneh Shabanzadeh ◽  
Norazak Senu ◽  
Kamyar Shameli ◽  
Maryam Mohaghegh Tabar
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Silver Nanoparticles ◽  
Reaction Temperature ◽  
Chemical Reduction ◽  
Size Control ◽  
Design Parameters ◽  
Ag Nps ◽  
Factors Affecting ◽  
Artificial Neural

Artificial neural network (ANN) models have the capacity to eliminate the need for expensive experimental investigation in various areas of manufacturing processes, including the casting methods. An understanding of the interrelationships between input variables is essential for interpreting the sensitivity data and optimizing the design parameters. Silver nanoparticles (Ag-NPs) have attracted considerable attention for chemical, physical, and medical applications due to their exceptional properties. The nanocrystal silver was synthesized into an interlamellar space of montmorillonite by using the chemical reduction technique. The method has an advantage of size control which is essential in nanometals synthesis. Silver nanoparticles with nanosize and devoid of aggregation are favorable for several properties. In this investigation, the accuracy of artificial neural network training algorithm was applied in studying the effects of different parameters on the particles, including the AgNO3concentration, reaction temperature, UV-visible wavelength, and montmorillonite (MMT) d-spacing on the prediction of size of silver nanoparticles. Analysis of the variance showed that the AgNO3concentration and temperature were the most significant factors affecting the size of silver nanoparticles. Using the best performing artificial neural network, the optimum conditions predicted were a concentration of AgNO3of 1.0 (M), MMT d-spacing of 1.27 nm, reaction temperature of 27°C, and wavelength of 397.50 nm.

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