scholarly journals Biogenic Nanosilver Mediated by Coir, Medicinal Plant Extracts and their Antimicrobial Validation

CORD ◽  
2017 ◽  
Vol 33 (2) ◽  
pp. 18
Author(s):  
Geethanjali Kanagaraju

Knowing the magnitude of therapeutic plants such as Micrococca mercurialis (MM), Abutilon palmeri (AP) and Callistemon citrinus (CC), we also planned to extend our research work on Cocusnucifera fibers (CF) and dust (CD) as it has copious medicinal properties. The current study deals with the green synthesis of silver nanoparticles (AgNPs) from fresh aqueous extracts and AgNO3 solution. The biogenic conversion of silver ion to silver is relatively expeditious at two different time intervals and pH. The isolated  silver nanoparticles (AgNPs) from the bio extracts were identified initially by scrutinizing the colour variations. The biosynthesized AgNPs were characterized by UV, XRD, Laser Diffraction Particle size Analyser, fluorescence spectroscopy, SEM and TEM. UV absorbance at 435-460nm for silver nanoparticles was observed for the above extracts. The XRD pattern of all extracts showed the distinctive Bragg peaks of face centre cubic (fcc) crystalline system available in nature. SEM and TEM analysis of the silver nanoparticles indicated that the particle size was in the range of 2-100nm with polygonal and spherical shapes. The biosynthesized AgNPs were evaluated for antimicrobial activities. The CFAgNPs showed an efficient antibacterial activity at lower concentration (25mg/ml) against Pseudomonas demolytica followed by Staphylococcus aureus and Escherichia coli. Similarly all plant extracts have better activity against fungal strains. It is concluded that the biogenic blend of AgNPs is simple, extremely rapid, beneficial, eco-friendly and more stable without any toxic effects. Of these, CFAgNps may be used for the preparation of antibacterial groupings against Pseudomonas demolytica and Staphylococcus aureus.

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1343
Author(s):  
Caroline Tyavambiza ◽  
Abdulrahman Mohammed Elbagory ◽  
Abram Madimabe Madiehe ◽  
Mervin Meyer ◽  
Samantha Meyer

Cotyledon orbiculata, commonly known as pig’s ear, is an important medicinal plant of South Africa. It is used in traditional medicine to treat many ailments, including skin eruptions, abscesses, inflammation, boils and acne. Many plants have been used to synthesize metallic nanoparticles, particularly silver nanoparticles (AgNPs). However, the synthesis of AgNPs from C. orbiculata has never been reported before. The aim of this study was to synthesize AgNPs using C. orbiculata and evaluate their antimicrobial and immunomodulatory properties. AgNPs were synthesized and characterized using Ultraviolet-Visible Spectroscopy (UV-Vis), Dynamic Light Scattering (DLS) and High-Resolution Transmission Electron Microscopy (HR-TEM). The antimicrobial activities of the nanoparticles against skin pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Methicillin Resistance Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) as well as their effects on cytokine production in macrophages (differentiated from THP-1 cells) were evaluated. The AgNPs from C. orbiculata exhibited antimicrobial activity, with the highest activity observed against P. aeruginosa (5 µg/mL). The AgNPs also showed anti-inflammatory activity by inhibiting the secretion of pro-inflammatory cytokines (TNF-alpha, IL-6 and IL-1 beta) in lipopolysaccharide-treated macrophages. This concludes that the AgNPs produced from C. orbiculata possess antimicrobial and anti-inflammation properties.


RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2804-2837
Author(s):  
Chhangte Vanlalveni ◽  
Samuel Lallianrawna ◽  
Ayushi Biswas ◽  
Manickam Selvaraj ◽  
Bishwajit Changmai ◽  
...  

Herein, we have reviewed new findings in the research domain of the green synthesis of silver nanoparticles using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015.


Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 998
Author(s):  
Kartini Kartini ◽  
Amarisa Alviani ◽  
Dia Anjarwati ◽  
Adinda Finna Fanany ◽  
Johan Sukweenadhi ◽  
...  

Silver nanoparticles (AgNPs) are an interesting metal nanoparticle that can be incorporated into pharmaceutical products, including for diabetic foot ulcers as an antimicrobial agent. Green synthesis of AgNPs using plant extracts has been drawing much attention as it is simple, eco-friendly, stable, and cost-effective. This present study was performed to evaluate the potential of three Indonesian medicinal plant extracts, namely Phyllanthus niruri (PN), Orthosiphon stamineus (OS), and Curcuma longa (CL), as reducing and capping agents in the green synthesis of AgNPs, and to optimize their concentrations. Based on the yields and characteristics of the formed nanoparticles, which were analyzed using a UV-Vis spectrophotometer, particle size analyzer, scanning electron microscope, and X-ray diffractometer, Phyllanthus niruri extract at a concentration of 0.5% was concluded as the best extract in the green synthesis of AgNPs. It is thereby a prospective reducing and capping agent for further scale-up studies.


Author(s):  
Maphibanri Maring ◽  
Akila Elias ◽  
V. B. Narayanaswamy

<p>Nanotechnology is a field that is rapidly growing, making an impact in all spheres of human life. In the current study, silver nanoparticles were synthesized using the ethanolic leaf extract of <em>Achras sapota. </em>Characterization was carried out using UV-Visible spectroscopy, FTIR, XRD, SEM and TEM. The formation of AgNPs was confirmed through UV-Visible spectroscopy by the colour change. Based on the XRD pattern, the crystalline property of the AgNPs was established. The functional group present in the ethanolic leaf extract of <em>Achras sapota</em> is responsible for the reduction of the Ag<sup>+</sup> ion which was studied through FTIR. From the SEM and TEM analysis, it was found that the formed nanoparticles are spherical in shape and nano in size. The biosynthesized AgNPs was evaluated for its antimicrobial activity against gram positive bacteria (<em>S. aureus and L. bacillus</em>) and gram negative bacteria (<em>E. coli and P. aeruginosa</em>) using disc diffusion for preliminary screening of antimicrobial activity and dilution method for evaluation of antibacterial effectiveness and effect of silver nanoparticles on bacterial growth and it was found to exhibit potential antimicrobial activity. The biosynthesized AgNPs was found to be efficient in terms of reaction time as well as stability, eco-friendly and cost effective.</p>


2021 ◽  
Vol 10 (1) ◽  
pp. 851-859
Author(s):  
Lebogang Mogole ◽  
Wesley Omwoyo ◽  
Elvera Viljoen ◽  
Makwena Moloto

Abstract The resistance of microorganisms towards antibiotics remains a big challenge in medicine. Silver nanoparticles (AgNPs) received attention recently for their characteristic nanosized features and their ability to display antimicrobial activities. This work reports the synthesis of AgNPs using the Citrus sinensis peels extract in their aqueous, mild, and less hazardous conditions. The effect of concentration variation (1%, 2%, and 3%) of the plant extracts on the size and shape of the AgNPs was investigated. The antimicrobial activities were tested against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae. Absorption spectra confirmed the synthesis by the surface Plasmon resonance peaks in the range 400–450 nm for all the AgNPs. FTIR spectra confirmed that Citrus sinensis peels extract acted as both reducing and surface passivating agent for the synthesized AgNPs. TEM revealed spherical AgNPs with average size of 12 nm for 3% concentration as compared to the agglomeration at 1% and 2%. All the AgNPs synthesized using Citrus sinensis peels extracts (1%, 2%, and 3%) exhibited antimicrobial activity against both gram-positive and negative bacteria. These results indicated a simple, fast, and inexpensive synthesis of silver nanoparticles using the Citrus sinensis peels extract that has promising antibacterial activity.


2021 ◽  
Author(s):  
Susmila Aparna Gaddam ◽  
Venkata Subbaiah Kotakadi ◽  
Gunasekhar. Kalavakunta ◽  
Josthna Penchalaneni ◽  
Varadarajulu Naidu Challagundla ◽  
...  

Abstract The current investigation highlights the green synthesis of silver nanoparticles (AgNPs) by the insectivorous plant Drosera spatulata Labill var.bakoensis, which is the first of its kind. The biosynthesized nanoparticles revealed a UV visible surface plasmon resonance (SPR) band at 427 nm. The natural phytoconstituents which reduce the monovalent silver were identified by FTIR. The particle size of the Ds-AgNPs was detected by the Nanoparticle size analyzer confirms that the average size of nanoparticles was around 23 ± 2 nm. Ds-AgNPs exhibit high stability because of their high negative zeta potential (-34.1 mV). AFM studies also revealed that the Ds-AgNPs were spherical in shape and average size ranges from 10 to 20 ± 5 nm. TEM analysis also revealed that the average size of Ds-AgNPs was also around 21 ± 4 nm and the shape is roughly spherical and well dispersed. The crystal nature of Ds-AgNPs was detected as a face-centered cube by the XRD analysis. Furthermore, studies on antibacterial and antifungal activities manifested outstanding antimicrobial activities of Ds-AgNPs compared with standard antibiotic Amoxyclav. In addition, demonstration of superior free radical scavenging efficacy coupled with potential in vitro cytotoxic significance on Human colon cancer cell lines (HT-29) suggests that the Ds-AgNPs attain excellent multifunctional therapeutic applications.


2020 ◽  
Vol 10 (19) ◽  
pp. 6973
Author(s):  
Hidayat Mohd Yusof ◽  
Nor’Aini Abdul Rahman ◽  
Rosfarizan Mohamad ◽  
Uswatun Hasanah Zaidan

The present study aimed to investigate the ability of Lactobacillus plantarum TA4 in tolerating Ag+ and its ability to produce silver nanoparticles (AgNPs). The biosynthesized AgNPs were characterized using UV–Visible spectroscopy (UV–Vis), dynamic light scattering (DLS), Fourier-transform infrared (FTIR), and high-resolution transmission electron microscope (HR-TEM). The cell biomass of L. plantarum TA4 demonstrated the ability to tolerate Ag+ at a concentration of 2 mM, followed by the formation of AgNPs. This was confirmed by the visual observation of color changes and a presence of maximum UV–Vis absorption centered at 429 nm. HR-TEM analysis revealed that the AgNPs were spherical with an average size of 14.0 ± 4.7 nm, while the SEM-EDX analysis detected that the particles were primarily located on the cell membrane of L. plantarum TA4. Further, DLS analysis revealed that the polydispersity index (PDI) value of biosynthesized AgNPs was 0.193, implying the monodispersed characteristic of NPs. Meanwhile, the FTIR study confirmed the involvement of functional groups from the cell biomass that involved in the reduction process. Moreover, biosynthesized AgNPs exhibited antibacterial activity against Gram-positive and Gram-negative pathogens in a concentration-dependent manner. Furthermore, the antioxidant property of biosynthesized AgNPs that was evaluated using the DPPH assay showed considerable antioxidant potential. Results from this study provide a sustainable and inexpensive method for the production of AgNPs.


2021 ◽  
Vol 10 (1) ◽  
pp. 421-429
Author(s):  
Humaira Rizwana ◽  
Mona S. Alwhibi ◽  
Hadeel A. Aldarsone ◽  
Manal Ahmed Awad ◽  
Dina A. Soliman ◽  
...  

Abstract Silver nanoparticles (AgNPs) are widely used for medical applications particularly as antimicrobial agents against multidrug-resistant microbial strains. Some plants stimulate the reduction of Ag ions to AgNPs. In this study, we prepared AgNPs via the green synthesis approach using fenugreek leaves grown in Saudi Arabia. Furthermore, we characterized these AgNPs and evaluated their antimicrobial activities against pathogenic yeast, bacteria, and fungi. The ultraviolet-visible peak at 380 nm confirmed the biosynthesis of NPs. Transmission electron microscopy analyses revealed particle size in the range of 9–57 nm with a spherical shape. Dynamic light scattering results confirm slight aggregation as the average particle size was shown as 68.71 nm and a polydispersity index of 0.083. The energy-dispersive X-ray spectroscopy results showed an intense peak at 3 keV, indicating the presence of elemental AgNPs. The synthesized AgNPs efficiently inhibit the growth of both Gram-positive and Gram-negative bacteria; however, varying degree of inhibition was shown toward fungi. The potent antimicrobial ability of the synthesized NPs can be attributed to their small size and round shape. Among all test organisms, the growth of Candida albicans and Helminthosporium sativum was remarkably affected by AgNPs treatment.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1005
Author(s):  
Aneta Salayová ◽  
Zdenka Bedlovičová ◽  
Nina Daneu ◽  
Matej Baláž ◽  
Zdenka Lukáčová Bujňáková ◽  
...  

A green synthetic route for the production of silver nanoparticles (AgNPs) using five different aqueous plant extracts, namely, Berberis vulgaris, Brassica nigra, Capsella bursa-pastoris, Lavandula angustifolia and Origanum vulgare, was investigated in this study. The present work demonstrates the influence of plant extract composition (antioxidant and total phenolic content) on the size and morphology of the produced AgNPs. The biosynthetic procedure was rapid and simple and was easily monitored via colour changes and ultraviolet and visible (UV-Vis) spectroscopy. Subsequently, measurement of zeta potential (ZP), photon cross-correlation spectroscopy (PCCS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) analysis were employed to characterise the as-synthesised nanoparticles. The XRD investigation confirmed the presence of Ag0 in the nanoparticles, and interactions between the bioactive compounds of the plants and the produced AgNPs were evident in the FTIR spectra. TEM indicated that the nanoparticles exhibited a bimodal size distribution, with the smaller particles being spherical and the larger having a truncated octahedron shape. In addition, the antimicrobial activity of the AgNPs was tested against five bacterial strains. All synthesised nanoparticles exhibited enhanced antimicrobial activity at a precursor concentration of 5 mM compared to the control substance, gentamicin sulphate, with the best results observed for AgNPs prepared with B. nigra and L. angustifolia extracts.


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