Spectral studies of silver nanoparticles biosynthesized by Origanum majorana

2018 ◽  
Vol 7 (2) ◽  
pp. 100-105 ◽  
Author(s):  
Moustafa Zahran ◽  
Maged El-Kemary ◽  
Shaden Khalifa ◽  
Hesham El-Seedi
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Metallic Nanoparticles ◽  
Spectral Studies ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Biosynthesized Agnps ◽  
The Stability ◽  
Origanum Majorana ◽  
Average Size

AbstractSilver nanoparticles (AgNPs) were biologically synthesized in an eco-friendly manner using aqueous leaf extract ofOriganum majoranaplant and silver nitrate (AgNO3) solution. Size, shape, and crystallinity of the biosynthesized AgNPs were determined by using a transmission electron microscope (TEM). Zeta potential analyzer was used to prove the stability of the metallic nanoparticles, while Fourier transform infrared spectroscopy was used to identify the bioreducing and capping agents. AgNPs were electrochemically investigated using cyclic voltammetry (CV), while the optical properties of the metallic nanoparticles were studied using UV-Vis and fluorescence spectroscopies. According to TEM images, AgNPs are spherical with an average size of 35 nm. TEM also refers to the presence of mono and polycrystalline AgNPs. The value of zeta potential (−39 mV) proved the stability of AgNPs caused by capping molecules ofO. majoranaplant. CV studies showed that AgNPs were electrochemically investigated at 0.39 mV. AgNPs showed a surface plasmon resonance peak at 440 nm, while the emission peak was detected at 466 nm. These nanoparticles are promising for many industrial and medical applications.

scholarly journals Myco-Fabricated Gold Nanoparticles from Aspergillus Tamarii MTCC5152, its Characterization and Dye Biodegradation

2021 ◽  
pp. 52-62
Author(s):  
Ragavy Radhakrishnan ◽  
Uthirappan Mani ◽  
Arumugam Gnanamani ◽  
Muthiah Shanmugavel
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Ftir Spectroscopy ◽  
Dye Degradation ◽  
Visual Observation ◽  
Surface Plasmon Resonance Peak ◽  
Sem Images ◽  
Aspergillus Tamarii ◽  
Plasmon Resonance Peak ◽  
Average Size

This work was initiated to investigate the myco-fabrication of gold nanoparticles (AuNPs) using a fungal strain, Aspergillus tamarii 5152 (A. tamarii MTCC 5152). The biosynthesized gold nanoparticles were characterized by visual observation, and using UV-Vis and FTIR spectroscopy, DSC, TGA, Zeta-potential, DLS and SEM analyses. NADH-dependent cofactor analysis and photocatalysis assays were carried out for NADH-dependent AuNPs biosynthesis and dye degradation ability. A maximum surface plasmon resonance peak for the AuNPs was recorded at 535 nm, followed by the identification of protein capping effect of the extract by FTIR spectroscopy. The average size (Z) of the nanoparticles observed was 39.15 nm, while SEM images showed crystallized rod-shaped structures ranging from 55-91 nm. A negative zeta potential of 10.5 mV showed repulsion between the nanoparticles, which indicates the stabilizing power of the fungal extract. Further, it was observed that NADH acts as a cofactor for the nanoparticle biosynthesis. The AuNPs were found to degrade crystal violet dye by 63%. From this study, it can be understood that the process of fungal mediated biosynthesis of AuNPs by A. tamarii MTCC 5152 is simple, less expensive, and could be utilized for bioremediation of toxic dye accumulation.

Green synthetic approach for starch capped silver nanoparticles and their antibacterial activity

2016 ◽  
Vol 88 (1-2) ◽  
pp. 61-69 ◽  
Author(s):  
Precious Nokwethemba Sibiya ◽  
Thokozani Xaba ◽  
Makwena Justice Moloto
Keyword(s):  
Silver Nanoparticles ◽  
Synthesis Method ◽  
Spherical Shape ◽  
Cubic Phase ◽  
Hydroxyl Groups ◽  
Synthetic Approach ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Transmission Electron ◽  
Average Size

AbstractIn this work silver nanoparticles (AgNPs) have been prepared from silver nitrate (AgNO3) precursor using a green synthesis method at room temperature. Starch with its abundance of hydroxyl groups and its biocompatibility was used as a capping and reducing agent. The formation of AgNPs was confirmed by absorption spectroscopy with the surface plasmon resonance peak at 400 nm. The sharp reflection at (111), (200), (220) and (311) was observed by powder X-ray diffraction (XRD), which indicated the presence of cubic phase AgNPs. Transmission electron microscopy (TEM) revealed that the average size of AgNPs were between 0.5 and 4 nm with a spherical shape under optimum conditions. The nanoparticles showed a decrease in size with an increase in precursor concentration as well as the increase in capping agent concentration. The nanoparticles also showed to be bactericidal towards the tested Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.

scholarly journals PREPARATION AND STABILITY OF SILVER AND PALLADIUM NANOPARTICLES STABILIZED BY POLYETHER LAPROL 5003 IN N,N – DIMETHYLFORMAMIDE MEDIA

2019 ◽  
Vol 62 (5) ◽  
pp. 50-55
Author(s):  
Alexander V. Bespalov ◽  
Yana O. Ivanova
Keyword(s):  
Palladium Nanoparticles ◽  
Metallic Nanoparticles ◽  
Potassium Thiocyanate ◽  
Reducing Agent ◽  
Spectral Studies ◽  
Optical Absorption Spectroscopy ◽  
Absorption Bands ◽  
The Stability ◽  
Average Size ◽  
Silver Cations

This paper is devoted to obtaining and investigating the stability of silver and palladium sols in N,N-dimethylformamide medium. Due to the unique properties exhibited by metals in the nanosized state, metallic nanoparticles are gaining increasing importance in various fields of application, science and technology. This makes the task of obtaining stable metal sols extremely urgent. The synthesis of aggregate-resistant organosols of metals is associated with a number of problems, since the metal sols obtained in organic media are much less stable than hydrosols. For this reason, there arises the challenge of choosing an appropriate stabilizer. In this study, the stabilizer was branched polyester Laprol 5003. A distinctive feature of the synthesis of silver sols was the absence of a special reducing agent, since N,N-dimethylformamide, used as a solvent, recovers silver cations  itself. As a result, stable sols of silver and palladium have been obtained in N,N-dimethylformamide medium. Sodium borohydride was used as the reducing agent for the synthesis of palladium nanoparticles. Spectral studies of the resulting sols were carried out. The silver and palladium nanoparticles were sized up by scanning electron microscopy. The procedure has shown that the average size of the silver particles formed in the N,N-dimethylformamide medium is 4 ± 2 nm, which is substantially smaller than the particles obtained in isopropanol medium by the borohydride method.  The silver sols aggregation in dimethylformamide under the action of potassium thiocyanate was studied via optical absorption spectroscopy. It has been found that the stability of the silver sol in dimethylformamide to the electrolyte is higher than that of the sol obtained in isopropanol. It has also been detected that several absorption bands are present in the optical spectrum of the palladium sol in dimethylformamide. The effect of the stabilizing polyester concentration on the stability of silver and palladium sols in N,N-dimethylformamide was studied. The result is that when the concentration of Laprol 5003 exceeds some quantity, a sharp increase in the aggregation time of sols is observed, which indicates a significant increase in their stability.

scholarly journals Ecofriendly synthesis of silver nanoparticles from leaves extract of Phyllanthus niruri (L.) and their antibacterial properties

2019 ◽  
Vol 9 (1-s) ◽  
pp. 196-200
Author(s):  
G Amalorpavamary ◽  
G Dineshkumar ◽  
K Jayaseelan
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Good Alternative ◽  
Diffusion Method ◽  
Surface Plasmon Resonance Peak ◽  
Phyllanthus Niruri ◽  
Plasmon Resonance Peak ◽  
Synthesis Of Nanoparticles ◽  
Average Size

In recent times, plant-mediated synthesis of nanoparticles has garnered wide interest owing to its inherent features such as rapidity, simplicity, eco-friendliness and cheaper costs. For the first time, silver nanoparticles were successfully synthesized using Phyllanthus niruri leaf extract in the current investigation. The silver nanoparticles were characterized by UV–Vis spectrophotometer and the characteristic surface plasmon resonance peak was identified to be 423 nm. The morphology of the silver nanoparticles was characterized by scanning electron microscopy (SEM). The size of the silver nanoparticles was found to be 10-50 nm, with an average size 15 nm.  FTIR analysis was done to identify the functional groups responsible for the synthesis of the AgNPs. The antibacterial potential of synthesized AgNPs was compared with that of aqueous extracts of P.niruri by well diffusion method. The AgNPs at 50µl concentration significantly inhibited bacterial growth against A.hydrophila (16 ± 0.09 mm). Thus AgNPs showed broad spectrum antibacterial activity at lower concentration and may be a good alternative therapeutic approach in future. Keywords: Phyllanthus niruri, AgNps, Aeromonas hydrophila, Antibacterial Activity.

scholarly journals Synthesis of biogenic silver nanoparticles from the seed coat waste of pistachio (Pistacia vera) and their effect on the growth of eggplant

2021 ◽  
Vol 10 (1) ◽  
pp. 1789-1800
Author(s):  
Masudulla Khan ◽  
Azhar U. Khan ◽  
Il Soo Moon ◽  
Raed Felimban ◽  
Raed Alserihi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Fly Ash ◽  
Plant Growth ◽  
Seed Coat ◽  
Silver Ions ◽  
Active Surface ◽  
Surface Plasmon Resonance Peak ◽  
Nanoparticle Suspension ◽  
Plasmon Resonance Peak ◽  
Average Size

Abstract Herein, the synthesis of silver nanoparticles using extracts of pistachio seed coat waste is investigated. The surface plasmon resonance peak at 443 nm was observed in the nanoparticles by using ultraviolet-visible spectroscopy (UV-Vis). To identify potential biomolecules involved in the bio-reduction of silver ions, Fourier-transform infrared spectroscopy (FTIR) was used. Scanning and transmission electron microscopy (SEM and TEM) show irregular shapes with an average size of ∼20 nm. The active surface determined by Brunauer, Emmett, and Teller analysis was 22 m2/g. The effect of silver nanoparticles on eggplants sprayed with a nanoparticle suspension of 75 mg/L led to increased plant growth and chlorophyll and carotenoid contents. The fly ash addition to the soil promoted plant growth. The highest increase in plant growth occurs when plants were sprayed with 75 ppm AgNPs in 20% fly ash amended soil.

BIOSYNTHESIZED SILVER NANOPARTICLES USING CATHARANTHUS ROSEUS AND THEIR ANTIBACTERIAL EFFICACY IN SYNERGY WITH ANTIBIOTICS; A FUTURE ADVANCEMENT IN NANOMEDICINE

2021 ◽  
pp. 116-124
Author(s):  
MONIKA GUPTA
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Catharanthus Roseus ◽  
Leaf Extract ◽  
Research Work ◽  
Resistant Bacteria ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
X Ray ◽  
Uniform Dispersion

Objective: This research work develops an approach to synthesize silver nanoparticles (AgNPs) by reduction of leaf extract of Catharanthus roseus plant. This study produces synthesized nanoparticles that have process-controlled attributes which make their antibiotic action highly efficient. These attributes include smaller size, proper morphology, uniform dispersion, metal ion content, and formation of functional groups. By optimizing the reduction process parameters, AgNPs gain the desired properties.  Methods: The biosynthesis of AgNPs process was performed using reaction of 10% (w/v) C. roseus leaf extract with AgNO3. The optimum conditions and concentration used for synthesis of nanoparticles were: 1 mM AgNO3, pH 5, and temperature 80°C with an incubation time of 72 h. All the above parameters were analyzed by ultraviolet-visible spectrophotometer with the surface plasmon resonance peak obtained at 440 nm. Results: Various characterization techniques were performed, namely, scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy, photoluminescence study, X-ray diffraction spectroscopy, Fourier transform infrared, dynamic light scattering, and atomic force microscopy. The results obtained from characterization confirmed the spherical morphology of the nanoparticles with size between 50 and 87 nm. In the current investigation, the antimicrobial activity of biosynthesized AgNPs was also determined using minimum inhibitory concentration and zone of inhibition methods against six different bacteria at different doses of AgNPs (100, 150, and 200 μg/ml) alone and also in combination with antibiotic-streptomycin. Conclusion: The results revealed that high concentration of AgNPs inhibits the bacterial growth. Furthermore, AgNPs revealed much stronger antibacterial action in synergy with streptomycin against antibiotic-resistant bacteria.

scholarly journals Synthesis of Silver Nanoparticles from Anagalis arvensis and Their Biomedical Applications

2018 ◽  
Author(s):  
Mohib Shah ◽  
Natasha Anwar ◽  
Samreen Saleem ◽  
Iqbal Munir ◽  
Niaz Ali Shah ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Reducing Power ◽  
Spherical Shape ◽  
Artemia Salina ◽  
Maximum Activity ◽  
Tem Analysis ◽  
Synthesis Of Nanoparticles ◽  
The Stability ◽  
Average Size ◽  
Biological Methods

Background. Nanotechnology is promising field for generating new applications. A green synthesis of nanoparticles through biological methods using plant extract have a reliable and ecofriendly approach to improve our global environment. Methods. Silver nanoparticles (AgNPs) were synthesized using aqueous extract of Anagalis arvensis L and silver nitrate and were physicochemically characterized. Results. The stability of AgNPs toward acidity, alkalinity, salinity and temperature showed that they remained stable at room temperature for more than two months. The SEM and TEM analysis of the AgNPs showed that they have a uniform spherical shape with an average size in the range of 40–78 nm. Further 1-Dibhenyl-2-Picrylhydrazl radical in Anagalis arvensis L.mediated AgNPs showed a maximum activity of 98% at concentration of 200μg/mL. Hydrogen peroxide scavenging assay in Anagalis arvensis L. mediated AgNPs showed a maximum activity of 85% at concentration of 200μg/mL. Reducing power of Anagalis arvensis L.Ag NPs exhibited a higher activity of 330 μg/mL at concentration of 200 μg/mL. These NPs have cytotoxic effects against brine shrimp (Artemia salina) nauplii with a value of 53% LD 178.04μg/mL. Conclusion. The AgNPs synthesized using Anagalis arvensis L. extract demonstrate a broad range of applications.

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 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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