scholarly journals Synthesis and Plasmonic Chiroptical Studies of Sodium Deoxycholate Modified Silver Nanoparticles

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1291 ◽  
Author(s):  
Jing Wang ◽  
Kai-Xuan Fei ◽  
Xin Yang ◽  
Shuai-Shuai Zhang ◽  
Yin-Xian Peng
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Hot Spots ◽  
Sodium Deoxycholate ◽  
Coulomb Interactions ◽  
Chiral Molecules ◽  
Ag Nps ◽  
Line Shapes ◽  
Visible Wavelength Range ◽  
Distinct Line

Sodium deoxycholate modified silver nanoparticles prepared in the presence of sodium deoxycholate as a chiral inducer exhibit plasmonic circular dichroism (CD) signals. The plasmon-induced chirality arises from the presence of chiral molecules (sodium deoxycholate) on the surface of Ag nanoparticles, which transfer their chiral properties to the visible wavelength range due to the Coulomb interactions between the chiral molecules and plasmonic nanoparticles. The prepared Ag nanoparticles (NPs) exhibit distinct line shapes of plasmonic CD, which can be tailored by varying the pH values of the solutions. A mechanism was proposed to explain the generation of the distinct plasmonic CD shapes, which indicated that the arrangements of chiral molecules in the plasmonic hot spots between Ag NPs are crucial for the induced plasmonic CD.

Optical and Morphological Properties of Silver Nanoparticles Synthesis by Q-Switched Nd-YAG Laser

2021 ◽  
Vol 1039 ◽  
pp. 215-224
Author(s):  
Noor Fakher Khdr ◽  
Bassam G. Rasheed ◽  
Baida M. Ahmed
Keyword(s):  
Surface Roughness ◽  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Laser Energy ◽  
Average Diameter ◽  
Laser Wavelength ◽  
Morphological Properties ◽  
Average Surface Roughness ◽  
Ag Nps ◽  
Average Surface

Abstract. Laser ablation of a silver target immersed in distilled water utilizing Nd: YAG laser with wavelengths of 532nm,1064nm, and 1320nm was carried out to fabricate silver nanoparticles. The synthesis of Ag NPs was carried out using various laser energy (200-1000 mJ) and different pulses (200-1000 pulse). Optical properties for the Ag nanoparticles solution were tested using UV-Visible spectrum, while the morphological properties for the Ag-nanoparticles solution after deposited on glass were tested using the atomic force microscope (AFM). The results showed that the synthesis of the Ag-nanoparticles using pulsed laser ablation in liquid (PLAL) (water) gives nanoparticles with homogeneous grain distribution and uniform surface roughness. It was found that the absorption peaks of Ag NPs increase by increasing the number of pulses shoot for the same laser wavelength and laser energy, and the reported maximum value of absorption peak is 0.363 when using 1000 pulses shoot. AFM results showed that the average diameter of the Ag NPs prepared by PLAL increases with increasing the laser wavelength. However, when using laser wavelengths of 1320nm,1064nm, and 532nm, the resulted average diameter of silver nanoparticles will be 55.38nm, 34.18nm, and 30.3nm, respectively. Finally, the average surface roughness of the Ag NPs prepared by PLAL increased with increasing the laser wavelength. The obtained average surface roughness of silver nanoparticles when using wavelengths of 1320nm,1064nm, and 532nm were 2.75nm, 1.19nm, and1.06nm, respectively.

Tuning the efficiency of CoFe2O4@rGO composite by Encapsulating Ag Nanoparticles for the photocatalytic degradation of Methyl violet dye and Energy storage systems

2021 ◽  
Author(s):  
S. Vijayalakshmi ◽  
Elanthamilan Elaiyappillai ◽  
Princy Merlin Johnson ◽  
Sharmila Lydia I
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Energy Storage ◽  
Ag Nanoparticles ◽  
Storage Systems ◽  
Methyl Violet ◽  
Ag Nps ◽  
Reduced Graphene ◽  
Simple Chemical ◽  
Co Precipitation

In the present work, silver nanoparticles encapsulated CoFe2O4@reduced Graphene oxide composite (Ag NPs/CoFe2O4@rGO) was prepared via a simple chemical co-precipitation technique. The formation of the materials was confirmed by various...

scholarly journals Silver nanoparticles: Green Synthesis and Their Antibacterial efficiency

2021 ◽  
Vol 59 (2) ◽  
pp. 214
Author(s):  
Dung Ngo Thanh ◽  
Nguyet Ha Minh ◽  
Tam Le Thi Thanh ◽  
Lu Le Trong
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Tannic Acid ◽  
Ag Nanoparticles ◽  
Sodium Citrate ◽  
Reducing Agents ◽  
Ag Nps ◽  
Silver Nps

In this study, silver nanoparticles were synthesized from aqueous silver nitrate through a simple and eco-friendly route using a combination of two reducing agents: sodium citrate and tannic acid. By this method, the obtained Ag nanoparticles (NPs) were stable within the studied period of six months. Besides, both TEM images and UV-Vis results showed that the size of silver NPs could be controlled by changing the concentration of tannic acid. The antibacterial ability of Ag NPs with different sizes were also examined. In detail, the smaller the Ag NPs were, the more efficient their antibacterial activity was.

scholarly journals Antibacterial activity of zinc oxide with silver nanoparticles

2018 ◽  
Vol 7 (2) ◽  
pp. 98-107
Author(s):  
Fouzia Bourfaa ◽  
Abderhamane Boutelala ◽  
Mohamed Salah Aida ◽  
Nadir Attaf ◽  
Fateh Merouane
Keyword(s):  
Silver Nanoparticles ◽  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Ag Nanoparticles ◽  
Sol Gel ◽  
Zno Films ◽  
Ag Nps ◽  
Health Related ◽  
Uv Visible ◽  
Absorbance Peak

Nanoscale materials and their unique properties make them attractive for research and health -related applications. Silver nanoparticles were synthesised and incorporated in zinc oxide (ZnO) thin films on glass and tissue, in order to study their effect on antibacterial activity. ZnO films with various contents of Ag nanoparticles were prepared by the sol –gel method. Xray diffraction revealed the polycrystalline structure of the films, scanning electron microscopy exhibited their dense and continuous structure and UV-visible spectroscopy for measurement and transmittance was at more than 87%. The absorbance peak of Ag NPS was centred at 351 nm. The diameter of Ag NPS was analysed by Zeta Sizer and the colloids ranged from 2 to 110 nm. The results indicate that ZnO with Ag NPs on tissue can resist the growth of this kind of bacteria, with the zone of inhibition of the bacteria ATTC 700603 at between 8 and 18 mm .Keywords: Ag nanoparticles, zinc oxide, tissue, antibacterial activity.

scholarly journals A Surface Mediated Supramolecular Chiral Phenomenon for Recognition of l- and d-Cysteine

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1027 ◽  
Author(s):  
Jing Wang ◽  
Shuai-Shuai Zhang ◽  
Xu Xu ◽  
Kai-Xuan Fei ◽  
Yin-Xian Peng
Keyword(s):  
Ag Nanoparticles ◽  
Chiral Recognition ◽  
Colloidal Solution ◽  
Total Surface Area ◽  
Chiral Molecules ◽  
Ag Nps ◽  
Sensing Platform ◽  
Bonding Interaction ◽  
Chiral Sensing ◽  
Uv Range

Chiral recognition is of fundamental importance in chemistry and life sciences and the principle of chiral recognition is instructive in chiral separation and enantioselective catalysis. Non-chiral Ag nanoparticles (NPs) conjugated with chiral cysteine (Cys) molecules demonstrate strong circular dichroism (CD) responses in the UV range. The optical activities of the l-/d-Cys capped Ag NPs are associated with the formation of order arrangements of chiral molecules on the surface of Ag NPs, which are promoted by the electrostatic attraction and hydrogen bonding interaction. The intensity of the chiroptical response is related to the total surface area of Ag NPs in the colloidal solution. The anisotropy factor on the order of 10−2 is acquired for Ag NPs with the size varying from ~2.4 to ~4.5 nm. We demonstrate a simple and effective method for the fabrication of a quantitative chiral sensing platform, in which mesoporous silica coated Ag nanoparticles (Ag@mSiO2) were used as chiral probes for recognition and quantification of Cys enantiomers.

scholarly journals Convenient conversion of hazardous nitrobenzene derivatives to aniline analogues by Ag nanoparticles, stabilized on a naturally magnetic pumice/chitosan substrate

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43670-43681
Author(s):  
Reza Taheri-Ledari ◽  
Seyedeh Shadi Mirmohammadi ◽  
Kobra Valadi ◽  
Ali Maleki ◽  
Ahmed Esmail Shalan
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Reduction Process ◽  
Ag Nps ◽  
Effective Catalyst ◽  
Aniline Derivatives ◽  
Magnetic Substrate

Silver nanoparticles (Ag NPs), as an effective catalyst for the reduction process of nitrobenzene derivatives to non-hazardous and useful aniline derivatives, are conveniently synthesized on an inherently magnetic substrate.

Facile preparation of Ag nanoparticles using uric acid and their applications in colorimetric detection and catalysis

2018 ◽  
Vol 10 (37) ◽  
pp. 4518-4524 ◽  
Author(s):  
Qijun Dai ◽  
Te Wei ◽  
Changli Lv ◽  
Fang Chai
Keyword(s):  
Silver Nanoparticles ◽  
Uric Acid ◽  
Ag Nanoparticles ◽  
Colorimetric Detection ◽  
Cost Effective ◽  
Reducing Agent ◽  
Ag Nps ◽  
Cost Effective Method ◽  
Facile Preparation

In this study, we have reported a facile, cost-effective method for the synthesis of silver nanoparticles (Ag NPs) using uric acid (UA) as the reducing agent.

scholarly journals Laser-Driven Aggregation in Dextran–Graft–PNIPAM/Silver Nanoparticles Hybrid Nanosystem: Plasmonic Effects

2020 ◽  
Vol 65 (3) ◽  
pp. 254
Author(s):  
O. A. Yeshchenko ◽  
A. O. Bartenev ◽  
A. P. Naumenko ◽  
N. V. Kutsevol ◽  
Iu. I. Harahuts ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Laser Wavelength ◽  
Solution Temperature ◽  
Optical Forces ◽  
Ag Nps ◽  
Induced Aggregation ◽  
Conformation Transition ◽  
Hybrid Nanosystem

The laser-induced aggregation in the thermosensitive dextran grafted-poly(N-isopropylacrylamide) copolymer/Ag nanoparticles (D–g–PNIPAM/AgNPs) hybrid nanosystem in water has been observed. The laser-induced plasmonic heating of Ag NPs causes the Lower Critical Solution Temperature (LCST) conformation transition in D–g–PNIPAM/AgNPs macromolecules which shrink during the transition. The shrinking decreases sharply the distance between the silver nanoparticles that launches the aggregation of Ag NPs and the appearance of plasmonic attractive optical forces acting between the nanoparticles. It has been shown that the approach of the laser wavelength to the surface plasmon resonance in Ag nanoparticles leads to a significant strengthening of the observed aggregation, which proves its plasmon nature. The laser-induced transformations in the D–g–PNIPAM/AgNPs nanosystem have been found to be essentially irreversible that differs principally them from the temperature-induced transformations. Such fundamental difference proves the crucial role of the optical forces arising due to the excitation of surface plasmons in Ag NPs.

scholarly journals Single-Step Green Synthesis of Highly Concentrated and Stable Colloidal Dispersion of Core-Shell Silver Nanoparticles and Their Antimicrobial and Ultra-High Catalytic Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1007
Author(s):  
Azam Ali ◽  
Mariyam Sattar ◽  
Fiaz Hussain ◽  
Muhammad Humble Khalid Tareen ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Tannic Acid ◽  
Rate Constant ◽  
Catalytic Properties ◽  
Colloidal Dispersion ◽  
Alkaline Condition ◽  
Core Shell ◽  
Average Particle ◽  
Ag Nps

The versatile one-pot green synthesis of a highly concentrated and stable colloidal dispersion of silver nanoparticles (Ag NPs) was carried out using the self-assembled tannic acid without using any other hazardous chemicals. Tannic acid (Plant-based polyphenol) was used as a reducing and stabilizing agent for silver nitrate in a mild alkaline condition. The synthesized Ag NPs were characterized for their concentration, capping, size distribution, and shape. The experimental results confirmed the successful synthesis of nearly spherical and highly concentrated (2281 ppm) Ag NPs, capped with poly-tannic acid (Ag NPs-PTA). The average particle size of Ag NPs-PTA was found to be 9.90 ± 1.60 nm. The colloidal dispersion of synthesized nanoparticles was observed to be stable for more than 15 months in the ambient environment (25 °C, 65% relative humidity). The synthesized AgNPs-PTA showed an effective antimicrobial activity against Staphylococcus Aureus (ZOI 3.0 mM) and Escherichia coli (ZOI 3.5 mM). Ag NPs-PTA also exhibited enhanced catalytic properties. It reduces 4-nitrophenol into 4-aminophenol in the presence of NaBH4 with a normalized rate constant (Knor = K/m) of 615.04 mL·s−1·mg−1. For comparison, bare Ag NPs show catalytic activity with a normalized rate constant of 139.78 mL·s−1·mg−1. Furthermore, AgNPs-PTA were stable for more than 15 months under ambient conditions. The ultra-high catalytic and good antimicrobial properties can be attributed to the fine size and good aqueous stability of Ag NPs-PTA. The unique core-shell structure and ease of synthesis render the synthesized nanoparticles superior to others, with potential for large-scale applications, especially in the field of catalysis and medical.

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