Polyhedral borane-capped coinage metal nanoparticles as high-performing catalysts for 4-nitrophenol reduction

2019 ◽  
Vol 55 (55) ◽  
pp. 7990-7993 ◽  
Author(s):  
Nathaniel E. Larm ◽  
Dronareddy Madugula ◽  
Mark W. Lee ◽  
Gary A. Baker
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Gold And Silver Nanoparticles ◽  
Coinage Metal ◽  
Stabilizing Agent ◽  
Boron Cluster ◽  
High Performing ◽  
Nitrophenol Reduction

Small (<5 nm) gold and silver nanoparticles and their bimetallic counterparts were prepared using the fundamental boron cluster [closo-B10H10]2− as the reducing and stabilizing agent.

scholarly journals Green ultrasonic synthesis, Characterization and Antibacterial activity of Silver and Gold Nanoparticles mediated by Ganoderma lucidum extract

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Gold Nanoparticles ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Metal Nanoparticles ◽  
Cytotoxic Activities ◽  
Gold And Silver Nanoparticles ◽  
Silver And Gold Nanoparticles ◽  
E Coli ◽  
Inhibition Zones

Metal nanoparticles possess an extensive scientific and technological significance due to their unique physiochemical properties and their potential applications in different fields like medicine. Silver and gold nanoparticles have shown to have antibacterial and cytotoxic activities. Conventional methods used in the synthesis of the metal nanoparticles involve use of toxic chemicals making them unsuitable for use in medical field. In our continued effort to explore for simple and eco-friendly methods to synthesize the metal nanoparticles, we here describe synthesis and characterization of gold and silver nanoparticles using Gonaderma lucidum, wild non-edible medicinal mushroom. G. lucidum mushroom contain bioactive compounds which can be involved in the reduction, capping and stabilization of the nanoparticles. Antibacterial activity analysis was done on E. coli and S. aureus. The synthesis was done on ultrasonic bath. Characterization of the metal nanoparticles was done by UV-VIS., High Resolution Transmission Electron Microscope (HRTEM) and FTIR. HRTEM analysis showed that both silver and gold nanoparticles were spherical in shape with an average size of 15.82±3.69 nm for silver and 24.73±5.124nm for gold nanoparticles (AuNPs). FTIR analysis showed OH and -C=C- stretching vibrations, an indication of presence of functional groups of biomolecules capping both gold and silver nanoparticles. AgNPs showed inhibition zones of 15.5±0.09mm and 13.3±0.14mm while AuNPs had inhibition zones of 14.510±0.35 and 13.3±0.50mm on E. coli and S. aureus respectively. The findings indicate the potential use of AgNPs and AuNPs in development of drugs in management of pathogenic bacteria.

Water-based synthesis of gold and silver nanoparticles with cuboidal and spherical shapes using luteolin tetraphosphate at room temperature

2018 ◽  
Vol 5 (4) ◽  
pp. 917-932 ◽  
Author(s):  
Francis J. Osonga ◽  
Phuong Le ◽  
David Luther ◽  
Laura Sakhaee ◽  
Omowunmi A. Sadik
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Room Temperature ◽  
Synthetic Methods ◽  
Gold And Silver Nanoparticles ◽  
Water Based

The demand for eco-friendly synthetic methods of metal nanoparticles is on the rise.

scholarly journals Light harvesting enhancement using metal nanoparticles

2021 ◽  
Vol 2 (5 (110)) ◽  
Author(s):  
Mohammad Tariq Yaseen
Keyword(s):  
Silver Nanoparticles ◽  
Optical Properties ◽  
Metal Nanoparticles ◽  
Light Harvesting ◽  
Field Enhancement ◽  
Optical Response ◽  
Resonance Wavelength ◽  
Optical Field ◽  
Localized Surface Plasmon ◽  
Gold And Silver Nanoparticles

Metal nanoparticles are very important for their optical properties when they interact with light. Metal nanoparticles have the ability to confine the collective oscillation of electrons, which is called localized surface plasmon resonance (LSPR). In this work, silver nanoparticles have been proposed to enhance light harvesting, which could be useful for different applications. Metal nanoparticles such as gold and silver nanoparticles have the ability to concentrate field in a very small space. In this study, gold and silver nanoparticles optical response was investigated using frequency domain simulation. The resonance wavelength of gold and silver nanoparticles was about 550 nm and 400 nm, respectively. Silver nanoparticles showed better LSPR performance than gold nanoparticles. Therefore, silver nanoparticles were chosen for optical field enhancement. Here silver nanoparticles were placed on a silicon substrate for optical field enhancement. To study the effect of size on the optical response of silver nanoparticles, the optical properties of this structure with different silver nanoparticles diameter values were investigated. Silver nanoparticles with 40 nm diameters showed a better optical response. To study the effect of the distance between silver nanoparticles on the optical response, different gap values were put between silver nanoparticles. The gap value of 4 nm showed a better optical response. The obtained results showed that the localized field is strongly dependent on the metal type, size, and space between nanoparticles. In addition, the optical field concentration can be controlled by tuning the size and space between silver nanoparticles. This will support localized field enhancement. The enhanced localized field will increase the field absorption near the surface, which can be beneficial for energy harvesting applications such as solar cells and detectors

scholarly journals One-step synthesis of gold and silver non-spherical nanoparticles mediated by Eosin Methylene Blue agar

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Diego Alberto Lomelí-Rosales ◽  
Adalberto Zamudio-Ojeda ◽  
Sara Angélica Cortes-Llamas ◽  
Gilberto Velázquez-Juárez
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Methylene Blue ◽  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Reduction Process ◽  
Gold And Silver Nanoparticles ◽  
Transmission Electron ◽  
One Step ◽  
Conventional Plate

AbstractNowadays, there are several approaches reported to accomplish the green synthesis of metal nanoparticles by using bacterial and fungi supernatants or by-products generated by these microorganisms. Therefore, agars as solely reductive regents have started to be used in order to obtain metal nanoparticles. This paper shows the results of the synthesis of gold and silver nanoparticles with different morphology, mainly triangular and truncated triangular, using Eosin Methylene Blue (EMB) agar as reducing agent. To control the reaction process, the necessary activation energy for the reducer was provided by three different techniques: microwave radiation, using a domestic microwave oven, ultraviolet radiation, and heating on a conventional plate. The evolution of the reduction process and stability of the samples was performed by ultraviolet visible spectroscopy. Morphology was carefully analyzed using high-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM). A one step synthesis for gold and silver nanoparticles was optimized with an eco-friendly and economic process.

scholarly journals Silver and gold nanoparticles as an integral part of nanooncology: current state of the problem

2021 ◽  
pp. 89-100 ◽  
Author(s):  
M.A. Osadchuk ◽  
N.V. Kireeva ◽  
N.P. Korzhenkov ◽  
M.V. Trushi
Keyword(s):  
Drug Delivery ◽  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Targeted Drug Delivery ◽  
Colloidal Stability ◽  
Multiple Use ◽  
High Permeability ◽  
Gold And Silver Nanoparticles ◽  
Current State ◽  
Potential Tool

Gold and silver nanoparticles are easily synthesized and the most effective nanostructures in clinical practice. Their optical properties, ease of synthesis, colloidal stability and the ability to form any surface for easier conjugation with biological particles, the ability to individual multiple use, make them especially important in oncology. Gold and silver nanoparticles are capable of providing targeted drug delivery, which depends on the photothermal, photodynamic, and antiangiogenic properties of the metal. Due to their exceptional properties, these nanoparticles are considered as a potential tool for the diagnosis of various types of cancer and drug delivery. The non-toxic and non-immunogenic nature of gold and silver nanoparticles, as well as their high permeability and retention effect, provide additional advantages, allowing drugs to easily penetrate and accumulate at tumor sites. The effectiveness of precious metal nanoparticles as radiosensitizers, dose enhancers and contrast agents is gaining increasing recognition. An important problem associated with the use of biogenic metal nanoparticles is the study of their genotoxicity, since they play an important role in the initiation and progression of abnormalities, including genetic ones.

Larvicidal activity of green synthesized silver nanoparticles and chitosan nanoparticles encapsulated Aloe vera gel extract against Musca domestica (Diptera: Muscidae)

2021 ◽  
Vol 14 ◽  
Author(s):  
Olfat M. El-Monairy ◽  
Ahmed A. El-Sayed ◽  
Manar M. Emara ◽  
Abla D. Abdel-Meguid
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Musca Domestica ◽  
Insecticidal Activity ◽  
Crude Extract ◽  
Chitosan Nanoparticles ◽  
Aloe Vera ◽  
Cost Effective ◽  
House Fly ◽  
Stabilizing Agent

Background: Metal nanoparticles synthesized by various chemical reactions have significantly gained worldwide interest for their use in biomedical applications. These processes exhibit a broad range of toxicity in none target organisms. To avoid the chemical toxicity, green synthesis of metal nanoparticles is proposed as a cost-effective and eco-friendly alternative. Aloe vera (A. vera) leaf extract is a medicinal agent with multiple properties including antibacterial effect. Its constituents include lignin, pectin and hemicellulose which can be used in the reduction of silver ions to produce silver nanoparticles (AgNPs). Objective: The aim of this article is to study the use of naturally occurring compounds as a reducing and stabilizing agent for the biosynthesis of nanoparticles and to investigate the insecticidal activity of these compounds against Musca domestica (M. domestica) larvae. Methods: Phytochemical analysis of A. vera gel extract was performed and the phytochemical components identified by Gas chromatography–mass spectrometry (GC-MS) analysis. AgNPs and encapsulated chitosan nanoparticles (CsNPs) were prepared by an eco-friendly method using A. vera gel extract as a reducing and stabilizing agent. A. vera-AgNPs and A. vera encapsulated CsNPs were characterized using Ultraviolet-visible spectrophotometer (UV–vis spectrum), Transmission Electron Microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Then, the insecticidal activity of these compounds was investigated against late second instar larvae of house fly. Results: : The most active ingredients identified by GC-MS analysis were Terpene and Sesquiterpens hydrocarbons. The synthesized AgNPs were spherical with average size about 12-75 nm as revealed by TEM. While encapsulated CsNPs were ranged between 34-75 nm and the shape seems spherical with dark parts confirmed the capsulated plant extract. FTIR and XRD confirmed the successful encapsulation of the gel extract within the chitosan nanoparticles. Results proved the insecticidal potential of the tested compounds against M. domestica larvae and the relative potency of encapsulated CsNPs was nearly 148.51 times more potent than A. vera crude extract whereas, AgNPs was nearly 40.65 times more potent than A. vera crude extract. Furthermore, a prolongation of larval duration and reduction in the percentage pupation and adult emergence were observed. Conclusion: Overall, green-synthesized silver and chitosan nanoparticles are used as a biopesticide for house fly control through safer and cost-effective approach.

Hydrazine Based Facile Synthesis and Ordered Assembly of Metal Nanoparticles (Au, Ag) on a Bacterial Surface Layer Protein Template

2008 ◽  
Vol 8 (7) ◽  
pp. 3565-3569 ◽  
Author(s):  
Sarang S. Puranik ◽  
Hrushikesh M. Joshi ◽  
S. B. Ogale ◽  
K. M. Paknikar
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Metal Salt ◽  
Chemical Reduction ◽  
Average Diameter ◽  
Protein Array ◽  
Gold And Silver Nanoparticles ◽  
Bacterial Surface ◽  
Transmission Electron ◽  
Ordered Assembly

An efficient and facile procedure is developed for concurrent in situ synthesis and ordered assembly of metal nanoparticles on a periodic two dimensional protein array. The S-layer protein of Bacillus subtilis exhibiting uniform pore size is used as template. Synthesis of gold and silver nanoparticles anchoring on the pores of S-layer is achieved by chemical reduction of respective metal salt laden protein template. Transmission electron microscopy reveals formation of well ordered and separated gold and silver nanoparticles with an average diameter of 6 ± 1 nm and 4 ± 1 nm, respectively. The periodic arrangement of nanoparticles is dictated by the native structure of S-layer protein array as the nanoparticle locations are found to be correlated to the nanosized pores of the crystalline S-layer array.

scholarly journals Complex coloration and antibacterial functionalization of silk fabrics based on noble metal nanoparticles

2019 ◽  
Vol 14 ◽  
pp. 155892501986694 ◽  
Author(s):  
Zhanyu Zhang ◽  
Xiaodan Lv ◽  
Qidan Chen ◽  
Jing An
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Fiber Surface ◽  
Noble Metal Nanoparticles ◽  
Localized Surface Plasmon ◽  
Color Strength ◽  
Gold And Silver Nanoparticles ◽  
Silk Fabrics

Noble metal nanoparticles and traditional dyes jointly colorate silk fabrics. Gold and silver nanoparticles were in situ synthesized on silk fabrics, and the complex coloration was realized by the integration of traditional dyes into the treated silk. The localized surface plasmon resonance properties of gold and silver nanoparticles were not affected by the coloration of dyed-on silk fabrics. The combined optical properties of nanoparticles and dyes extended the color range and enhanced the color strength (K/S) of silk fabrics. Ultraviolet–visible diffuse absorption spectroscopy and scanning electron microscopy demonstrated the in situ synthesis of gold and silver nanoparticles on silk fabrics. The coloration of traditional dyes influenced the morphologies of gold and silver nanoparticles on fiber surface slightly. The silk fabrics with complex coloration showed significant antibacterial property. The complex coloration based on particular nanoparticles and dyes provides a promising strategy to develop multifunctional textiles.

Procaine Detection Using Hybrids of Cobalt-Metalloporphyrin with Gold and Silver Nanoparticles

2019 ◽  
Vol 41 (1) ◽  
pp. 43-43
Author(s):  
Anca Lascu Anca Lascu ◽  
Anca Palade Anca Palade ◽  
Mihaela Birdeanu and Eugenia Fagadar Cosma Mihaela Birdeanu and Eugenia Fagadar Cosma
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Hybrid Materials ◽  
Noble Metal Nanoparticles ◽  
Silver Colloid ◽  
Gold And Silver Nanoparticles ◽  
Coexisting Forms ◽  
Vis Spectroscopy ◽  
Inorganic Nanomaterials ◽  
Two Hybrid

Two organic-inorganic nanomaterials derived from Co(II)-tetra(3-hydroxyphenyl)porphyrin (Co-3OHPP) and noble metal nanoparticles, namely: Co-porphyrin-nanoAu (Co-3OHPP/nAu) and Co-porphyrin-nanoAg (Co-3OHPP/nAg) were obtained and tested for their capacity to detect procaine. Both hybrids present changes in UV-vis spectroscopy after interaction with procaine, in the same range of procaine concentration. The silver colloid is more easily obtainable and more economically affordable and its hybrid has a wider range of procaine detection from 5.39 x 10-5 mol l-1 to 28.04 x 10-5 mol l-1 concentration, thus being useful for the monitoring of the anesthesic remanence in patients’ plasma. Besides, the plasmonic band of the hybrid is more clearly defined. AFM studies were performed to compare the morphology of the two hybrid materials, Co-3OHPP/nAu and Co-3OHPP/nAg after being exposed to procaine. Both materials display triangular geometries that in case of Co-3OHPP/nAg are not very well defined taking also the form of kvatarons and these two coexisting forms generate pyramidal architectures.

Sign in / Sign up

Export Citation Format

Share Document