scholarly journals The Role of Calix[n]arenes and Pillar[n]arenes in the Design of Silver Nanoparticles: Self-Assembly and Application

2020 ◽  
Vol 21 (4) ◽  
pp. 1425 ◽  
Author(s):  
Pavel Padnya ◽  
Vladimir Gorbachuk ◽  
Ivan Stoikov
Keyword(s):  
Gold Nanoparticles ◽  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Self Assembly ◽  
Silver Ions ◽  
Attractive Alternative ◽  
Controlled Synthesis ◽  
Plasmonic Sensors ◽  
Redox Stability

Silver nanoparticles (AgNPs) are an attractive alternative to plasmonic gold nanoparticles. The relative cheapness and redox stability determine the growing interest of researchers in obtaining selective plasmonic and electrochemical (bio)sensors based on silver nanoparticles. The controlled synthesis of metal nanoparticles of a defined morphology is a nontrivial task, important for such fields as biochemistry, catalysis, biosensors and microelectronics. Cyclophanes are well known for their great receptor properties and are of particular interest in the creation of metal nanoparticles due to a variety of cyclophane 3D structures and unique redox abilities. Silver ion-based supramolecular assemblies are attractive due to the possibility of reduction by “soft” reducing agents as well as being accessible precursors for silver nanoparticles of predefined morphology, which are promising for implementation in plasmonic sensors. For this purpose, the chemistry of cyclophanes offers a whole arsenal of approaches: exocyclic ion coordination, association, stabilization of the growth centers of metal nanoparticles, as well as in reduction of silver ions. Thus, this review presents the recent advances in the synthesis and stabilization of Ag (0) nanoparticles based on self-assembly of associates with Ag (I) ions with the participation of bulk platforms of cyclophanes (resorcin[4]arenes, (thia)calix[n]arenes, pillar[n]arenes).

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.

Green Synthesis of silver, copper, gold nanoparticles using Terminalia arjuna bark and their effect on seed germination

2020 ◽  
Vol 10 ◽  
Author(s):  
Rama Sharma ◽  
Hariom Gupta
Keyword(s):  
Gold Nanoparticles ◽  
Silver Nanoparticles ◽  
Seed Germination ◽  
Metal Nanoparticles ◽  
Vigna Unguiculata ◽  
Terminalia Arjuna ◽  
Biological Applications ◽  
Scattering Technique ◽  
Copper Gold ◽  
Light Scattering Technique

Background: Terminalia arjuna has many biological applications and their metal nanoparticles have no hazardous effect on the environment. We have demonstrated that Terminalia arjuna bark mediated metal nanoparticles can be used to enhance the germination of seeds. Methods: To evaluate the effect on germination we treated Vigna unguiculata (black eyed peas) seeds with copper, silver and gold nanoparticles synthesized by Terminalia arjuna bark. The synthesized metal nanoparticles were characterized by UVspectroscopy and size was confirmed by diffraction light scattering technique. Results: After incubation of 48 hours, the effects were observed. It was observed that Vigna unguiculata (black eyed peas) seed showed 30% germination in silver nanoparticles solution and 70% in copper nanoparticles, 0% was observed in gold nanoparticles. Conclusions: The results obtained in the study showed the relevance of nanobiotechnology in agriculture to boost the production of crops.

scholarly journals Silver nanoparticles – wolves in sheep's clothing?

2015 ◽  
Vol 4 (3) ◽  
pp. 563-575 ◽  
Author(s):  
Rasmus Foldbjerg ◽  
Xiumei Jiang ◽  
Teodora Miclăuş ◽  
Chunying Chen ◽  
Herman Autrup ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Molecular Mechanisms ◽  
Silver Ions ◽  
Nanoparticle Toxicity ◽  
Intracellular Fate

We review the cellular and molecular mechanisms behind silver nanoparticle toxicity and their intracellular fate. In addition, the role of silver ions in the toxicity of silver nanoparticles is discussed.

scholarly journals The role of ligands in coinage-metal nanoparticles for electronics

2017 ◽  
Vol 8 ◽  
pp. 2625-2639 ◽  
Author(s):  
Ioannis Kanelidis ◽  
Tobias Kraus
Keyword(s):  
Metal Nanoparticles ◽  
Self Assembly ◽  
Colloidal Stability ◽  
Chemical Nature ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Coinage Metal ◽  
Conductive Composites ◽  
Particle Shapes

Coinage-metal nanoparticles are key components of many printable electronic inks. They can be combined with polymers to form conductive composites and have been used as the basis of molecular electronic devices. This review summarizes the multidimensional role of surface ligands that cover their metal cores. Ligands not only passivate crystal facets and determine growth rates and shapes; they also affect size and colloidal stability. Particle shapes can be tuned via the ligand choice while ligand length, size, ω-functionalities, and chemical nature influence shelf-life and stability of nanoparticles in dispersions. When particles are deposited, ligands affect the electrical properties of the resulting film, the morphology of particle films, and the nature of the interfaces. The effects of the ligands on sintering, cross-linking, and self-assembly of particles in electronic materials are discussed.

Effect of silver nanoparticles on biofilms of microorganisms (review)

10.12737/8117 ◽  
2015 ◽  
Vol 9 (1) ◽  
pp. 0-0
Author(s):  
Гладких ◽  
P. Gladkikh
Keyword(s):  
Silver Nanoparticles ◽  
High Efficiency ◽  
Antibacterial Properties ◽  
Silver Ions ◽  
Experimental Models ◽  
Human Pathogens ◽  
Antibiotic Resistant ◽  
Medical Supplies ◽  
Antibiotic Drugs

Nanotechnology enter in all spheres of human activity, particularly in medicine. Using nanoprogress allows the use of various nanostructures in the traditional methods therapy of various pathologies. The growing resistance to antibiotic drugs among human pathogens strains of microorganisms requires the development of alternatives. Silver nanoparticles are current contenders for the role of an alternative to modern antibiotics. They are able to transfer therapeutic agents, act on the membrane of microbial cells, disrupting their livelihoods and leading to death, as they are less toxic than silver ions. The use of nanoparticles is an effective tool in combating formed biofilms on medical supplies, and prevent to their education. Nanoparticles have proved positively against many antibiotic-resistant strains of microorganisms, including planktonic phase P. aureginosa. Synergistic effect observed while using of nanoparticles and various antibiotics. Antibacterial properties studied in experimental models of peritonitis and meningoencephalitis. In case of peritonitis high efficiency.

scholarly journals Hydrothermal Assisted Biogenic Synthesis of Silver Nanoparticles And Their Anticandidal Activity On Virulent Candida Isolates From COVID-19 Patients

2021 ◽  
Author(s):  
Fatma O Khalil ◽  
Enas M. Ghonaim ◽  
Shimaa Abed El-sattar ◽  
Sally W. Elkhadry ◽  
Hala El-Refai ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Fourier Transforms ◽  
Silver Ions ◽  
Thymus Vulgaris ◽  
Remarkable Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Anticandidal Activity

Abstract Till now the exact mechanism and effect of biogenic silver nanoparticles on fungus is an indefinable question. To focus on this issue, we prepared hydrothermal assisted thyme coated silver nanoparticles (T/AgNPs) and their toxic effect on Candida isolates is described. The role of thyme (Thymus Vulgaris) in the reduction of silver ions and stabilization of T/AgNPs are estimated by Fourier transforms infrared spectroscopy, structure and size of present silver nanoparticles were detected via atomic force microscopy as well as high-resolution transmission electron microscopy. The biological activity of T/AgNPs was observed against Candida isolates from COVID-19 Patients. Testing of virulence of Candida species using Multiplex PCR. T/AgNPs proved highly effective against Candida albicans, Candida kruzei, Candida glabrata and MIC values ranging from 156.25 to 1,250 µg/mL and MFC values ranging from 312.5 to 5,000 µg/mL. The structural and morphological modifications due to T/AgNPs on Candida albicans were detected by TEM. It was highly observed that when Candida albicans cells were subjected to 50 and 100 µg/mL T/AgNPs, a remarkable change in the cell wall and cell membrane was observed.

scholarly journals Coordination cage hosting ultrafine and highly catalytically active gold nanoparticles

2021 ◽  
Author(s):  
Xinxin Hang ◽  
Shentang Wang ◽  
Huan Pang ◽  
Qiang Xu
Keyword(s):  
Gold Nanoparticles ◽  
Metal Nanoparticles ◽  
Controlled Synthesis ◽  
Au Nps ◽  
Ultrafine Metal ◽  
Catalytically Active ◽  
Size Controlled

Ultrafine metal nanoparticles (MNPs) with size <2 nm are of great interest due to their superior catalytic capabilities. Herein, we report the size-controlled synthesis of gold nanoparticles (Au NPs) by...

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