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 ◽  
...  

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.

Author(s):  
Azam Ali ◽  
Mehrukh Zehravi ◽  
Muhammad Humble Khalid Treen ◽  
Jiri Militky ◽  
Fiaz Hussain ◽  
...  

The versatile one-pot green synthesis of a highly concentrated and stable colloidal dispersion of AgNPs 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 AgNPs 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) AgNPs, capped with poly-tannic acid (AgNPs-PTA). The average particle size of AgNPs-PTA was found 9.90 ± 1.60 nm. The colloidal dispersion of synthesized nanoparticles was observed stable for more than 15 months in the ambient environment (25 oC, 65 % relative humidity). The synthesized AgNPs-PTA showed an effective antimicrobial activity against Staphylococcus Aureus Escherichia coli. Ag-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. Furthermore, AgNPs-PTA were stable for more than 15 months under ambient conditions. 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 biomedical.


2021 ◽  
Vol 59 (2) ◽  
pp. 214
Author(s):  
Dung Ngo Thanh ◽  
Nguyet Ha Minh ◽  
Tam Le Thi Thanh ◽  
Lu Le Trong

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.


Author(s):  
Margarita Skiba ◽  
Viktoria Vorobyova ◽  
Oleksandr Pivovarov

The green synthesis of metallic nanoparticles paved the way to improve and protect the environment bydecreasing the use of toxic chemicals. A simple and eco-friendly method for silver nanoparticles (AgNPs) synthesis employing the aqueous extract obtained from grape pomace by plasma-chemical extraction technique was developed. The reduction of silver ions in solution was monitored using UV–visible absorption spectroscopy. The synthesised nanoparticles were characterised using scaning electron microscopy (SEM) and dynamic light scattering measurement (DLS). The sizes of the spherical silver particles were found to be in the range of 27–33 nm. The effect of silver ions concentrations on the synthesis of silver nanoparticles and average particle size was investigated. As-prepared Ag NPs had an excellent catalytic activity as a catalyst for the degradation of ibuprofen, which was carried out in 50 s. The current findings are equally extendable for safeguarding the aquatic environment against the pollution caused by drugs and microbial activity via a facile, highly economical, rapid and efficient reduction/degradation method based on the catalytic potential of Ag NPs. The report emphasizes the effect of the size of silver nanoparticles on the degradation rate of hazardous dyes - methyl blue by NaBH4..


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.


2016 ◽  
Vol 39 (4) ◽  
pp. 465-473 ◽  
Author(s):  
Tae Yoon Kim ◽  
Song-Hyun Cha ◽  
Seonho Cho ◽  
Youmie Park

RSC Advances ◽  
2017 ◽  
Vol 7 (68) ◽  
pp. 42900-42908 ◽  
Author(s):  
Gulzar Muhammad ◽  
Muhammad Ajaz Hussain ◽  
Muhammad Amin ◽  
Syed Zajif Hussain ◽  
Irshad Hussain ◽  
...  

Hydrogel forming polysaccharides are attracting attention for the design of diverse nature silver nanoparticles (Ag NPs) with potential biological applications.


2014 ◽  
Vol 11 (4) ◽  
pp. 1503-1509
Author(s):  
Baghdad Science Journal

Objective: In this study ,the effects of silver nanoparticles (Ag NPs)were investigated on the liver and kidney tissues. Methodology: The produced nanoparticles have an average particle size of about 30 nm. Eighteen male albino rats were used by dividing them into three groups, each group comprise 6 rats. First group(control group) given food and water like other groups by liberty. Second group was tail injected by (AgNPs) at dose of (0.4 mg/kg. body weight/day). Third group was injected by (AgNPs) at dose of (0.6 mg/kg. body weight/day) for 15 days. All animals were sacrified at the end of experiment. The liver and kidney tissues specimens were fixed in 10% formalin and histological preparations were carried out then stained with H&E. Pathological changes in liver and kidney tissues were showed. Results: Histopathological studies revealed the harmful effect of the silver nanoparticles uses on the liver and kidney rats, second group that treated with Ag NPs (0.4 mg/kg.body.weight/day), kidney sections showed enlargement of collecting tubules, increase in interstitial tissue medulla, necrosis and enlargement in proximal and distal convoluted tubules. Liver showed enlargement of the central vein and degeneration of hepatic cells. Third group that treated with Ag NPs (0.6 mg/kg. body weight/day); kidney sections showed hyperplasia of the interstitial connective tissue of renal medulla with hemorrhages, renal cortex showed, degenerative changes and necrosis of proximal and distal convoluted tubules. Liver section showed congestion and necrosis of hepatic cells. Conclusion: Silver nanoparticles cause damage in liver and kidney tissues. Recommendation: Further study is needed for the effect of Ag NPs on the other tissues.


2017 ◽  
Vol 57 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Abdul A. Buhroo ◽  
Gousul Nisa ◽  
Syed Asrafuzzaman ◽  
Ram Prasad ◽  
Razia Rasheed ◽  
...  

AbstractThe present exploration is focused on the bio-fabrication of silver nanoparticles (Ag NPs) usingTrichodesma indicumaqueous leaf extract as a reducing agent. The synthesized Ag NPs were productively characterized by UV-vis spectroscopy, XRD, and TEM studies. The photosynthesis of Ag NPs was done at room temperature for 24 h and at 60°C. The green synthesis of spherical-shaped Ag NPs bio-fabricated fromT. indicumwith a face centred cubic structure showed average particle sizes of 20–50 nm, which is inconsistent with the particle size calculated by the XRD Scherer equation and TEM analysis. We further explored the larvicidal efficacy of biosynthesized Ag NPs with leaf extracts ofT. indicumagainstMythimna separata. The results showed that Ag NPs (20–50 nm) ofT. indicumpossess good larvicidal activity againstM. separatawith an LC50of 500 ppm. Thus, we can advocate that Ag NPs of 20–50 nm size extracted fromT. indicummay be considered in the pest management programme ofM. separatain future.


2014 ◽  
Vol 13 (01) ◽  
pp. 1450008 ◽  
Author(s):  
R. Soleyman ◽  
A. Pourjavadi ◽  
N. Masoud ◽  
A. Varamesh

In the current study, γ- Fe 2 O 3/ SiO 2/ PCA / Ag -NPs hybrid nanomaterials were successfully synthesized and characterized. At first, prepared γ- Fe 2 O 3 core nanoparticles were modified by SiO 2 layer. Then they were covered by poly citric acid (PCA) via melting esterification method as well. PCA shell acts as an effective linker, and provides vacancies for conveying drugs. Moreover, this shell as an effective capping agent directs synthesis of silver nanoparticles ( Ag -NPs) via in situ photo-reduction of silver ions by sunlight-UV irradiation. This system has several benefits as a suitable cancer therapy nanomaterial. Magnetic nanoparticles (MNPs) can guide Ag -NPs and drugs to cancer cells and then Ag -NPs can affect those cells via Ag -NPs anti-angiogenesis effect. Size and structure of the prepared magnetic hybrid nanomaterials were characterized using FTIR and UV-Vis spectra, AFM and TEM pictures and XRD data.


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