scholarly journals The Effect of pH on the Size of Silver Nanoparticles Obtained in the Reduction Reaction with Citric and Malic Acids

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5444
Author(s):  
Lukasz Marciniak ◽  
Martyna Nowak ◽  
Anna Trojanowska ◽  
Bartosz Tylkowski ◽  
Renata Jastrzab
Keyword(s):  
Silver Nanoparticles ◽  
Citric Acid ◽  
Malic Acid ◽  
Silver Ions ◽  
Reduction Reaction ◽  
Heating Time ◽  
Molar Ratio ◽  
Vis Spectroscopy ◽  
Wide Ph Range ◽  
Average Size

In colloidal methods, the morphology of nanoparticles (size and shape) as well as their stability can be controlled by changing the concentration of the substrate, stabilizer, adding inorganic salts, changing the reducer/substrate molar ratio, and changing the pH and reaction time. The synthesis of silver nanoparticles was carried out according to the modified Lee and Meisel method in a wide pH range (from 2.0 to 11.0) using citric acid and malic acid, without adding any additives or stabilizers. Keeping the same reaction conditions as the concentration of acid and silver ions, temperature, and heating time, it was possible to determine the relationship between the reaction pH, the type of acid, and the size of the silver nanoparticles formed. Obtained colloids were analyzed by UV-Vis spectroscopy and investigated by means of Transmission Electron Microscope (TEM). The study showed that the colloids reduced with citric acid and malic acid are stable over time for a minimum of seven weeks. We observed that reactions occurred for citric acid from pH 6.0 to 11.0 and for malic acid from pH 7.0 to 11.0. The average size of the quasi-spherical nanoparticles changed with pH due to the increase of reaction rate.

Green Synthesis of Silk Sericin-Based Silver Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 487-490 ◽  
Author(s):  
Jia Li Ding ◽  
Wen Wu
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Room Temperature ◽  
Reduction Reaction ◽  
In Situ Reduction ◽  
Silk Sericin ◽  
Vis Spectroscopy ◽  
Highly Dispersed ◽  
Average Size

Green synthesis of silver nanoparticles (AgNPs) using the silk sericin (SS) solution by in situ reduction at room temperature is reported. The effect of pH on the reduction reaction is studied by UV-Vis spectroscopy. The structure of the sericin-based silver nanoparticles is characterized by TEM. According to the TEM images, the average size of the silver nanoparticles is about 16 nm. The silver nanoparticles are highly dispersed and stable in silk sericin solution for monthes.

Testing of photocatalytic potential of silver nanoparticles produced through nonthermal plasma reduction reaction and stabilized with saccharides

2021 ◽  
pp. 1-14
Author(s):  
N.U.H. Altaf ◽  
M.Y. Naz ◽  
S. Shukrullah ◽  
H.N. Bhatti
Keyword(s):  
Silver Nanoparticles ◽  
Band Gap ◽  
Light Exposure ◽  
Argon Plasma ◽  
Silver Ions ◽  
Reduction Reaction ◽  
Diameter Distribution ◽  
Light Spectrum ◽  
Plasma Reduction ◽  
Narrow Diameter Distribution

In this study, silver nanoparticles (AgNPs) were produced through an atmospheric pressure plasma reduction reaction and tested for photodegradation of methyl blue (MB) under sunlight exposure. The argon plasma born reactive species were used to reduce silver ions to AgNPs in the solution. Glucose, fructose and sucrose were also added in the solution to stabilize the growth process. The glucose stabilized reaction produced the smallest nanoparticles of 12 nm, while sucrose stabilized reaction produced relatively larger nanoparticles (14 nm). The nanoparticles exhibited rough morphology and narrow diameter distribution regardless of stabilizer type. The narrow diameter distribution and small band gap helped activating majority of nanoparticles at a single wavelength of light spectrum. The band gap energy of AgNPs varied from 2.22 eV to 2.41 eV, depending on the saccharide type. The photoluminescence spectroscopy of AgNPs produced emission peaks at 413 nm, 415 nm, and 418 nm. The photocatalytic potential of AgNP samples was checked by degrading MB dye under sunlight. The degradation reaction reached a saturation level of 98% after 60 min of light exposure.

scholarly journals Green Synthesis and Catalytic Activity of Silver Nanoparticles Based on Piper chaba Stem Extracts

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1777 ◽  
Author(s):  
Md. Mahiuddin ◽  
Prianka Saha ◽  
Bungo Ochiai
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Ftir Spectroscopy ◽  
Visual Observation ◽  
Face Centered Cubic ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Face Centered ◽  
Average Size

A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.

scholarly journals Green Synthesis of Silver Nanoparticles using Salacca zalacca Extract as Reducing Agent and It’s Antibacterial Activity

2019 ◽  
Vol 31 (12) ◽  
pp. 2804-2810
Author(s):  
Anti Kolonial Prodjosantoso ◽  
Oktanio Sigit Prawoko ◽  
Maximus Pranjoto Utomo ◽  
Lis Permana Sari
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Silver Ions ◽  
Reduction Reaction ◽  
Face Centered Cubic ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Face Centered

In this article, the synthesis of silver nanoparticles through a reduction reaction process using Salacca zalacca extract is reported. The AgNPs were characterized using X-ray diffraction, transmission electron microscopy, Fourier transform infrared and UV-visible spectrophotometry methods. The AgNPs antibacterial activity was determined against of Gram-positive bacteria (Staphylococcus epidermidis) and Gram-negative bacteria (Escherichia coli). The main functional groups contained in Salacca zalacca extract are carbonyl, hydroxyl and nitrile groups, which are believed to reduce the silver ions to metal. The surface plasmon resonance values of brownish red AgNPs are in the range of 410 nm to 460 nm. The structure of AgNPs is face centered cubic (FCC). The diameter of silver nanoparticles crystallite is 14.2 ± 2.6 nm. The AgNPs growth inhibition zones of Escherichia coli and Staphylococcus epidermidis are 9.6 mm and 9.2 mm, respectively.

scholarly journals Optimization of biogenic synthesis of silver nanoparticles from flavonoid-rich Clinacanthus nutans leaf and stem aqueous extracts

2020 ◽  
Vol 7 (7) ◽  
pp. 200065 ◽  
Author(s):  
Siti Nur Aishah Mat Yusuf ◽  
Che Nurul Azieyan Che Mood ◽  
Nor Hazwani Ahmad ◽  
Doblin Sandai ◽  
Chee Keong Lee ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Functional Groups ◽  
Silver Ions ◽  
Cost Effective ◽  
Aqueous Extracts ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The Face ◽  
Clinacanthus Nutans

Background : Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesize and characterize the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs were synthesized from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost-effective and eco-friendly method. Results : The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114.7 and 129.9 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10 to 300 nm and 10 to 180 nm, with average of 101.18 and 75.38 nm, respectively. The zeta potentials of AgNP-L and AgNP-S were recorded at −42.8 and −43.9 mV. X-ray diffraction analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. Fourier transform infrared spectrophotometer analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis. Conclusion : These results showed that the biogenically synthesized nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.

scholarly journals H2Ti3O7 Nanotubes Decorated with Silver Nanoparticles for Photocatalytic Degradation of Atenolol

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mariana Hinojosa-Reyes ◽  
Roberto Camposeco-Solís ◽  
Facundo Ruiz ◽  
Nereyda Niño Martínez ◽  
Vicente Rodríguez González ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Photocatalytic Degradation ◽  
Silver Ions ◽  
Homogeneous Distribution ◽  
Photocatalytic Process ◽  
X Ray Diffraction ◽  
Electron Recombination ◽  
Vis Spectroscopy ◽  
Temperature Programmed ◽  
Strong Attachment

The photocatalytic degradation/adsorption process of the β-blocker atenolol (ATL) under UV irradiation is described using two types of silver decorated catalysts: silver/titania and silver/titanates. The silver ions were reduced on the surface of TiO2-P25-Degussa using gallic acid. Silver/titanates were prepared by a microwave-assisted hydrothermal method using the silver/titania as the starting material to obtain the hydrogen titanate (H2Ti3O7) structure with tubular morphology. These materials were characterized by X-ray diffraction, UV-Vis spectroscopy, N2 physisorption, temperature programmed reduction, TEM, and FTIR spectroscopy. During the photocatalytic process, the ATL molecules were completely converted to amino-diol byproducts. It is the first time that these materials have been applied during the photocatalytic process in the degradation of pharmaceuticals products. The success of the silver nanoparticles (2 nm) consists of the homogeneous distribution over the surface of titanate nanotubes inhibiting the hole/electron recombination promoting the oxidation process. The Ag@H2Ti3O7 with a concentration of silver as 1.0% shows the highest adsorption/degradation of ATL than the Ag@TiO2 and the P25-Degussa. The great performance in the reuse test consists in the strong attachment of the silver nanoparticles on the titanium surface that inhibits the silver lixiviation during the photocatalytic tests.

On the Influence of Silver Nanoparticles Size in the Electrical Conductivity of PEDOT: PSS

2010 ◽  
Vol 644 ◽  
pp. 85-90 ◽  
Author(s):  
Rebeca G. Melendez ◽  
Karla J. Moreno ◽  
Ivana Moggio ◽  
Eduardo Arias ◽  
Arturo Ponce ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Reducing Agent ◽  
Molar Ratio ◽  
Plasmon Band ◽  
Vis Spectroscopy

In this paper, we studied the influence of the silver nanoparticles size on the electrical conductivity of PEDOT:PSS in Ag(PEDOT:PSS) films. The silver nanoparticles were synthesized in presence of PEDOT:PSS by varying the molar ratio between AgNO3 and the reducing agent (NaBH4). Both the particle size determined by TEM and the plasmon band obtained by UV-Vis spectroscopy were found to be strongly dependent on the reducing agent concentration. The electrical conductivity increases inversely with the concentration of reducing agent from 5.24 x 10-4 up to 1.63 S/cm; three orders of magnitude higher than pristine PEDOT:PSS.

scholarly journals Synthesis and Characterization of Silver Nanoparticles Using Cannonball Leaves and Their Cytotoxic Activity against MCF-7 Cell Line

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Preetha Devaraj ◽  
Prachi Kumari ◽  
Chirom Aarti ◽  
Arun Renganathan
Keyword(s):  
Silver Nanoparticles ◽  
Cell Line ◽  
Average Particle Size ◽  
Cancer Cell Line ◽  
Silver Ions ◽  
Average Particle ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Vis Spectroscopy ◽  
Mcf 7

Cannonball (Couroupita guianensis) is a tree belonging to the family Lecythidaceae. Various parts of the tree have been reported to contain oils, keto steroids, glycosides, couroupitine, indirubin, isatin, and phenolic substances. We report here the synthesis of silver nanoparticles (AgNPs) using cannonball leaves. Green synthesized nanoparticles have been characterized by UV-Vis spectroscopy, SEM, TEM, and FTIR. Cannonball leaf broth as a reducing agent converts silver ions to AgNPs in a rapid and ecofriendly manner. The UV-Vis spectra gave surface plasmon resonance peak at 434 nm. TEM image shows well-dispersed silver nanoparticles with an average particle size of 28.4 nm. FTIR showed the structure and respective bands of the synthesized nanoparticles and the stretch of bonds. Green synthesized silver nanoparticles by cannonball leaf extract show cytotoxicity to human breast cancer cell line (MCF-7). Overall, this environmentally friendly method of biological silver nanoparticles production provides rates of synthesis faster than or comparable to those of chemical methods and can potentially be used in various human contacting areas such as cosmetics, foods, and medical applications.

scholarly journals Green and Rapid Synthesis of Anticancerous Silver Nanoparticles bySaccharomyces boulardiiand Insight into Mechanism of Nanoparticle Synthesis

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Abhishek Kaler ◽  
Sanyog Jain ◽  
Uttam Chand Banerjee
Keyword(s):  
Silver Nanoparticles ◽  
Reaction Time ◽  
Cell Mass ◽  
Nanoparticle Synthesis ◽  
Silver Ions ◽  
Saccharomyces Boulardii ◽  
Breast Cancer Cell Lines ◽  
X Rays ◽  
Metallic Nanoparticle ◽  
Vis Spectroscopy

Rapidly developing field of nanobiotechnology dealing with metallic nanoparticle (MNP) synthesis is primarily lacking control over size, shape, dispersity, yield, and reaction time. Present work describes an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) by cell free extract (CFE) ofSaccharomyces boulardii. Parameters such as culture age (stationary phase growth), cell mass concentration (400 mg/mL), temperature (35°C), and reaction time (4 h), have been optimized to exercise a control over the yield of nanoparticles and their properties. Nanoparticle (NP) formation was confirmed by UV-Vis spectroscopy, elemental composition by EDX (energy dispersive X-rays) analysis, and size and shape by transmission electron microscopy. Synthesized nanoparticles had the size range of 3–10 nm with high negative zeta potential (−31 mV) indicating excellent stability. Role of proteins/peptides in NP formation and their stability were also elucidated. Finally, anticancer activity of silver nanoparticles as compared to silver ions was determined on breast cancer cell lines.

scholarly journals Green Strategy–Based Synthesis of Silver Nanoparticles for Antibacterial Applications

2021 ◽  
Vol 3 ◽  
Author(s):  
Kenneth Ssekatawa ◽  
Denis K. Byarugaba ◽  
Charles D. Kato ◽  
Eddie M. Wampande ◽  
Francis Ejobi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Maximum Growth ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Microscopy Imaging ◽  
Prunus Africana ◽  
Vis Spectroscopy ◽  
Biosynthesized Agnps ◽  
Average Size

Antibiotics have been the nucleus of chemotherapy since their discovery and introduction into the healthcare system in the 1940s. They are routinely used to treat bacterial infections and to prevent infections in patients with compromised immune systems and enhancing growth in livestock. However, resistance to last-resort antibiotics used in the treatment of multidrug-resistant infections has been reported worldwide. Therefore, this study aimed to evaluate green synthesized nanomaterials such as silver nanoparticles (AgNPs) as alternatives to antibiotics. UV-vis spectroscopy surface plasmon resonance peaks for AgNPs were obtained between 417 and 475 nm. An X-ray diffraction analysis generated four peaks for both Prunus africana extract (PAE) and Camellia sinensis extract (CSE) biosynthesized AgNPs positioned at 2θ angles of 38.2°, 44.4°, 64.5°, and 77.4° corresponding to crystal planes (111), (200), (220), and (311), respectively. A dynamic light-scattering analysis registered the mean zeta potential of +6.3 mV and +0.9 mV for PAE and CSE biosynthesized nanoparticles, respectively. Fourier transform infrared spectroscopy spectra exhibited bands corresponding to different organic functional groups confirming the capping of AgNPs by PAE and CSE phytochemicals. Field emission scanning electron microscopy imaging showed that AgNPs were spherical with average size distribution ranging from 10 to 19 nm. Biosynthesized AgNPs exhibited maximum growth inhibitory zones of 21 mm with minimum inhibitory concentration and minimum bactericidal concentration of 125 and 250 μg/ml, respectively, against carbapenem-resistant bacteria.

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