scholarly journals Phyto-Functionalized Silver Nanoparticles Derived from Conifer Bark Extracts and Evaluation of Their Antimicrobial and Cytogenotoxic Effects

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 217
Author(s):  
Irina Macovei ◽  
Simon Vlad Luca ◽  
Krystyna Skalicka-Woźniak ◽  
Liviu Sacarescu ◽  
Petronela Pascariu ◽  
...  

Silver nanoparticles synthesized using plant extracts as reducing and capping agents showed various biological activities. In the present study, colloidal silver nanoparticle solutions were produced from the aqueous extracts of Picea abies and Pinus nigra bark. The phenolic profile of bark extracts was analyzed by liquid chromatography coupled to mass spectrometry. The synthesis of silver nanoparticles was monitored using UV-Vis spectroscopy by measuring the Surface Plasmon Resonance band. Silver nanoparticles were characterized by attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, dynamic light scattering, scanning electron microscopy, energy dispersive X-ray and transmission electron microscopy analyses. The antimicrobial and cytogenotoxic effects of silver nanoparticles were evaluated by disk diffusion and Allium cepa assays, respectively. Picea abies and Pinus nigra bark extract derived silver nanoparticles were spherical (mean hydrodynamic diameters of 78.48 and 77.66 nm, respectively) and well dispersed, having a narrow particle size distribution (polydispersity index values of 0.334 and 0.224, respectively) and good stability (zeta potential values of −10.8 and −14.6 mV, respectively). Silver nanoparticles showed stronger antibacterial, antifungal, and antimitotic effects than the bark extracts used for their synthesis. Silver nanoparticles obtained in the present study are promising candidates for the development of novel formulations with various therapeutic applications.

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1377
Author(s):  
Chandra Kishore Somasundaram ◽  
Raji Atchudan ◽  
Thomas Nesakumar Jebakumar Immanuel Edison ◽  
Suguna Perumal ◽  
Rajangam Vinodh ◽  
...  

Herein, Sargassum coreanum (marine algae)-mediated silver nanoparticles (AgNPs) were successfully synthesized by a simple reduction method. The synthesized AgNPs were characterized using ultraviolet-visible spectroscopy, attenuated total reflection Fourier transformed infrared spectroscopy, X-ray diffractometry, field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray (EDX) spectroscopy, and high-resolution transmission electron microscopy (HR-TEM) analysis. The acquired colloidal AgNPs were strongly absorbed around 420 nm and displayed brown color under visible light. The XRD pattern of AgNPs exposed their face-centered cubic geometry along with crystalline nature. The HRTEM images of synthesized AgNPs confirmed the mean particle size of 19 nm with a distorted spherical shape, and the calculated interlayer distance (d-spacing value) was about 0.24 nm. Further, the catalytic degradation of methylene blue using sodium borohydride and AgNPs was monitored using UV–vis spectroscopy. The result revealed that AgNPs performed as a superior catalyst, which completely degraded MB in 20 min. The rate constant for MB degradation was calculated to be 0.106 min−1, demonstrating that the marine algae-mediated AgNPs had outstanding catalytic activity. This approach is easy and environmentally benign, which can be applied for environmental-based applications such as dye degradation and pollutant detoxification.


2016 ◽  
Vol 40 ◽  
pp. 120-127 ◽  
Author(s):  
Nalan Oya San Keskin ◽  
Nur Koçberber Kılıç ◽  
Gönül Dönmez ◽  
Turgay Tekinay

Nowadays, green and efficient synthetic strategies have been gaining great interest for the synthesis of nanoparticles. In this study, the biosynthesis of silver nanoparticles and its photocatalytic activity for photodegradation of organic dye and antimicrobial property was studied. The initial syntheses of Ag nanoparticles were characterized by UV–Vis spectrophotometer and showed the surface plasmon resonance band at 430-450 nm. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) study showed evidence that proteins are possible reducing agents. The structure of AgNPs was determined by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). SEM and TEM studies revealed the synthesized AgNPs to be spherical. The AgNPs exhibited photocatalytic activity for photodegradation of organic dye such as Methylene Blue. Approximately 18% degradations of methylene blue within 4 h was observed with biosynthesized Ag nanoparticles in the photocatalytic degradation process.


Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1541 ◽  
Author(s):  
Corneliu Tanase ◽  
Lavinia Berta ◽  
Năstaca Alina Coman ◽  
Ioana Roșca ◽  
Adrian Man ◽  
...  

Biosynthesized silver nanoparticles (AgNPs) are widely used in Pharmacy and Medicine. In particular, AgNPs synthesized and mediated by plant extracts have shown topossess several biological activities. In the present study, AgNPs were synthesized using Picea abies L. stem bark extract as reducing agent. Factors, such as metal ion solution, pH, and time, which play a role in the AgNPs synthesis, were assessed. The synthesized AgNPs were characterized by Ultraviolet-Visible Spectrometry, Fourier transform infrared spectroscopy, and Transmission Electron Microscopy (TEM). Further, the study has been extended to evaluate the antimicrobial and antioxidant activity of AgNPs. The broad peak obtained at 411–475 nm (UV-Vis spectroscopy), and the color change pattern, confirmed the synthesis of AgNPs. TEM results showed spherical or rarely polygonal AgNPs with an average size of 44 nm at pH = 9. The AgNPs showed antioxidant activity and antibacterial effect against human pathogenic Gram-positive and Gram-negative bacteria. The results show that spruce bark extract is suitable for obtaining AgNPs, with antibacterial and antioxidant activity.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hend M. Tag ◽  
Amna A. Saddiq ◽  
Monagi Alkinani ◽  
Nashwa Hagagy

AbstractHaloferax sp strain NRS1 (MT967913) was isolated from a solar saltern on the southern coast of the Red Sea, Jeddah, Saudi Arabia. The present study was designed for estimate the potential capacity of the Haloferax sp strain NRS1 to synthesize (silver nanoparticles) AgNPs. Biological activities such as thrombolysis and cytotoxicity of biosynthesized AgNPs were evaluated. The characterization of silver nanoparticles biosynthesized by Haloferax sp (Hfx-AgNPs) was analyzed using UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The dark brown color of the Hfx-AgNPs colloidal showed maximum absorbance at 458 nm. TEM image analysis revealed that the shape of the Hfx-AgNPs was spherical and a size range was 5.77- 73.14 nm. The XRD spectra showed a crystallographic plane of silver nanoparticles, with a crystalline size of 29.28 nm. The prominent FTIR peaks obtained at 3281, 1644 and 1250 cm− 1 identified the Functional groups involved in the reduction of silver ion reduction to AgNPs. Zeta potential results revealed a negative surface charge and stability of Hfx-AgNPs. Colloidal solution of Hfx-AgNPs with concentrations ranging from 3.125 to 100 μg/mL was used to determine its hemolytic activity. Less than 12.5 μg/mL of tested agent showed no hemolysis with high significant decrease compared with positive control, which confirms that Hfx-AgNPs are considered non-hemolytic (non-toxic) agents according to the ISO/TR 7405-1984(f) protocol. Thrombolysis activity of Hfx-AgNPs was observed in a concentration-dependent manner. Further, Hfx-AgNPs may be considered a promising lead compound for the pharmacological industry.


Author(s):  
S C Joshi ◽  
Utkarsh Kaushik ◽  
Aproova Upadhyaya ◽  
Priyanka Sharma

ABSTRACTObjective: The synthesis of nanoparticles from biological processes is evolving a new era of research interests in nanotechnology. Silver nanoparticlesare usually synthesized by chemicals and physical method, which are quite toxic and flammable in nature. This study deals with an environmentfriendly biosynthesis process of antibacterial silver nanoparticles using Momordica charantia fruit.Methods: AgNO3 (5 mM) was allowed to react with fruit extract of M. charantia. Biosynthesis of AgNPs was optimized by changing temperature,pH, and solvent. The silver nanoparticles so formed were characterized using ultraviolet-visible (UV-VIS) spectroscopy, Fourier transform infraredspectroscopy (FTIR), dynamic light scattering (DLS), atomic force microscope (AFM), and scanning electron microscopy (SEM).Results: UV-VIS spectra show absorption peak between 420 and 430 nm. The FTIR analysis showed the alcoholic, lactam, and nitro group presentin the plant extract, which were responsible for the reduction in AgNPs. The SEM images showed the size distribution of the nanoparticles and theaverage size was found to be 50-100 nm. By DLS analysis and AFM analysis, average sizes of the silver nanoparticles were of 150 nm. The results ofthese analyses confirmed the formation of silver nanoparticles. Silver nanoparticles were tested against Bacillus cereus and Staphylococcus epidermidisstrains using disc diffusion method and were found to be effective.Conclusion: Silver nanoparticles so synthesized in this study using fruit extract of M. charantia are simple, easy, and effective technique of nanoparticlesproduction.Keywords: Silver nanoparticles, Momordica charantia, Optimization, Antibacterial, Atomic force microscope, Scanning electron microscopy.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1777 ◽  
Author(s):  
Md. Mahiuddin ◽  
Prianka Saha ◽  
Bungo Ochiai

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.


2018 ◽  
Vol 78 (1) ◽  
pp. 235-246 ◽  
Author(s):  
D. Dixit ◽  
D. Gangadharan ◽  
K. M. Popat ◽  
C. R. K. Reddy ◽  
M. Trivedi ◽  
...  

Abstract A simple and eco-friendly method for the synthesis of hybrid bead silver nanoparticles (AgNPs) employing the aqueous extract derived from natural and renewable source namely tropical benthic green seaweed Ulva flexuosa was developed. This route involves the reduction of Ag+ ions anchored onto macro porous methacrylic acid copolymer beads to AgNPs for employing them as antibacterial agents for in vitro water disinfection. The seaweed extract itself acts as a reducing and stabilizing agent and requires no additional surfactant or capping agent for forming the AgNPs. The nanoparticles were analyzed using high-resolution transmission electron microscopy, UV–Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis and inductively coupled plasma optical emission spectroscopy. The study elucidates that such biologically synthesized AgNPs exhibit potential antibacterial activity against two Gram positive (Bacillus subtilis, Staphylococcus aureus) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacterial strains tested. The bacterial count in treated water was reduced to zero for all the strains. Atomic force microscopy was performed to confirm the pre- and post-state of the bacteria with reference to their treatment with AgNPs. Attributes like facile environment-friendly procedure, stability and high antibacterial potency propel the consideration of these AgNPs as promising antibacterial entities.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5047-5057
Author(s):  
Corneliu Tanase ◽  
Adrian Nisca ◽  
Argeime Lopez

Extracts obtained from the bark of woody plants are used for their high content in polyphenolic compounds with various biological activities. Thus, it is important to evaluate the heavy metals in various tree barks, as these pollutants may end up in the final product, affecting its properties and having potential health implications. This study assessed the heavy metal content in the barks of spruce (Picea abies) and pine (Pinus sylvestris and Pinus nigra) collected from different areas in Romania. After collecting the vegetal material from different sites, the bark samples were appropriately processed and analyzed via inductively coupled plasma optical emission spectroscopy (ICP-OES). The results showed that 6 out of 8 tested samples exceeded the normal values of selenium (Se). Arsenic (As) and cadmium (Cd) were not detected in any sample, while other metals (chromium (Cr); lead (Pb); nickel (Ni)) were detected in variable amounts. Moreover, relatively high levels of heavy metals were recorded in a spruce bark sample collected from the seemingly most unpolluted site. Although further studies are needed to determine the effects of these heavy metals on extraction yields and their transfer into the final extracts, their presence might indicate a potential problem.


Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 160 ◽  
Author(s):  
Temoor Ahmed ◽  
Muhammad Shahid ◽  
Muhammad Noman ◽  
Muhammad Bilal Khan Niazi ◽  
Faisal Mahmood ◽  
...  

Amongst serious biotic factors deteriorating crop yield, the most destructive pathogen of rice is Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial leaf blight (BLB) disease. This study involved targeted use of biogenic silver nanoparticles (AgNPs) to control BLB in order to cope with the disadvantages of chemical disease control. AgNPs were biologically synthesized from natively isolated Bacillus cereus strain SZT1, which was identified through 16S rRNA gene sequence analysis. Synthesis of AgNPs in bacterial culture supernatant was confirmed through UV-VIS spectroscopy. Fourier transform infrared spectroscopy (FTIR) confirmed that the existence of AgNPs was stabilized with proteins and alcoholic groups. X-ray diffraction (XRD) data revealed the crystalline nature and imaging with scanning electron microscopy (SEM) and transmission electron microscopy (TEM), showing the spherical shape of AgNPs with particle sizes ranging from 18 to 39 nm. The silver presence in AgNPs was further confirmed by energy dispersive spectra. Biogenic AgNPs showed substantial antibacterial activity (24.21 ± 1.01 mm) for Xoo. In a pot experiment, AgNPs were found to be effective weapons for BLB by significantly increasing the plant biomass with a decreased cellular concentration of reactive oxygen species and increased concentration of antioxidant enzyme activity.


2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.


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