scholarly journals Green Synthesis and Characterization of Silver Nanoparticles Using Citrullus lanatus Fruit Rind Extract

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Michael Ndikau ◽  
Naumih M. Noah ◽  
Dickson M. Andala ◽  
Eric Masika

The wide-scale application of silver nanoparticles (AgNPs) in areas such as chemical sensing, nanomedicine, and electronics has led to their increased demand. Current methods of AgNPs synthesis involve the use of hazardous reagents and toxic solvents. There is a need for the development of new methods of synthesizing AgNPs that use environmentally safe reagents and solvents. This work reports a green method where silver nanoparticles (AgNPs) were synthesized using silver nitrate and the aqueous extract of Citrullus lanatus fruit rind as the reductant and the capping agent. The optimized conditions for the AgNPs synthesis were a temperature of 80°C, pH 10, 0.001 M AgNO3, 250 g/L watermelon rind extract (WMRE), and a reactant ratio of 4 : 5 (AgNO3 to WMRE). The AgNPs were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy exhibiting a λmax at 404 nm which was consistent with the spectra of spherical AgNPs within the wavelength range of 380–450 nm, and Cyclic Voltammetry (CV) results showed a distinct oxidation peak at +291 mV while the standard reference AgNPs (20 nm diameter) oxidation peak occurred at +290 mV, and Transmission Electron Microscopy (TEM) revealed spherical shaped AgNPs. The AgNPs were found to have an average diameter of 17.96±0.16 nm.

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
A. V. Yakovlev ◽  
O. Yu. Golubeva

This paper presents an optimisation of the synthesis of silver nanoparticles encapsulated in a biological shell. The synthesis was carried out in an aqueous solution of silver nitrate. Sodium borohydride was used as a reducing agent. Lysozyme served as a bioactive coating agent. The samples produced were studied using dynamic light scattering, transmission electron microscopy, and UV-Vis spectroscopy. The function of the dependence of the reagent ratio in obtained sols on optical properties is shown. Furthermore, the influence of the synthesis temperature, reactant ratio, and order of mixing on the particle size distribution parameters is shown. The optimal reagent mass ratio, NaBH4 : LYZ : AgNO3 = 0.22 : 0.77 : 1, is established. The resulting composition allows the synthesis of particles with a mean diameter of 18 nm and a bioshell thickness of ≈3.5 nm. Moreover, the necessity of the synthesis optimisation and precise parameter control is clearly demonstrated.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
C. Q. Zhang ◽  
Y. M. Wang ◽  
S. Z. Li ◽  
X. D. Feng ◽  
L. H. Liu ◽  
...  

A series of novel composite microfibers composed of β-cyclodextrin (β-CDs) functionalized POM (polyoxymethylene) were prepared using electrospining technology with a mixture of hexafluoroisopropanol (HFIP) and N,N-dimethylformamide (DMF) as solvent. The concentration of β-CDs with respect to the POM was varied from 0 to 50 wt.%. The effect of β-CDs content on the morphology of POM/β-CD composite microfiber was investigated. The results showed that the introduction of β-CDs reduced the surface roughness and porosity of the microfibers, and the morphology of the fibers was changed. The increase of β-CDs content from 10% to 50% has led to increased average diameter of POM/β-CD composite fiber from 2.1 μm to 6.4 μm. The mechanical properties of the blend fiber mats were further investigated. In addition, silver nanoparticles were introduced to the POM/β-CD composite microfiber matrices during electrospinning. The POM/β-CD composite fiber allows CDs to form host–guest complexes with various small molecules and macromolecules. The TEM, SEM, XRD, and XPS were utilized to characterize the prepared samples. The data suggest that Ag nanoparticles were homogeneously distributed within the POM/β-CD fibers, and no aggregation was observed. The catalytic activity of Ag nanoparticles was tracked by ultraviolet-visible (UV-vis) spectroscopy which showed excellent catalytic degradation performance of organic dyes in the presence of NaBH4. The Ag/POM/β-CD mats are promising for use in waste treatment, molecular recognition, catalysis, and so on.


2021 ◽  
Vol 10 (3) ◽  
pp. 16-24
Author(s):  
Sherin Monichan ◽  
P. Mosae Selvakumar ◽  
Christine Thevamithra ◽  
M. S. A. Muthukumar Nadar ◽  
Jesse Joel

Silver nanoparticles has been used since ages, even till now it is exploited in almost all areas like medicine, textiles, industries, cosmetics, purification, dying and many more. There are many approaches which are used to synthesize silver nanoparticles. However, these approaches are either harmful to the environment or very costly. Therefore, green synthesis of silver nanoparticles (AgNPs) using leaves of Filicium decipiens eco-friendly and a very reliable method to procure AgNPs. Characterization of synthesized AgNPs were then done using UV-Vis spectroscopy and fluorescence which confirmed the formation of AgNPs, scanning electron microscope (SEM)confirmed its shape to be round and X-ray diffraction (XRD) determined its crystalline nature as face centered cubic structure. Furthermore, Dynamic Light Scattering (DLS) was also done in order to know the average diameter and zeta potential of AgNPs. However, it did not show potential results due to the aggregates formed during the green synthesis of AgNPs. In addition to this, anti-microbial test against bacteria such as gram negative (Escherichia. Coli) and gram positive (Bacillus.spc) were done using well-diffusion method and also its application of antimicrobial activity was tested over fabric to understand its application in textile industries. In both the cases, AgNPs showed more efficiency in gram negative bacteria than gram- positive.


2014 ◽  
Vol 4 (3) ◽  
pp. 43-46
Author(s):  
Tan Man Nguyen ◽  
Hai Le ◽  
Huu Tu Le ◽  
Thu Hong Tran ◽  
Duy Hang Nguyen ◽  
...  

Silver nanoparticles were prepared from (Ag+) aqueous solution by the method of γ-ray irradiation using chitosan as stabilizer. The saturated conversion dose (Ag+ à Ago) determined by UV-Vis spectroscopy was found to be about 16 kGy. The UV-Vis spectrum showed that an absorption peak at λmax = 400 nm due to surface plasma resonance. The image of transmission electron microscopy (TEM) showed that the silver nanoparticles were mostly spherical in shape and the average diameter was of about ~ 12 nm. The prepared colloidal silver nanoparticles solution was in good stability during storage time.


Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 909 ◽  
Author(s):  
Federico Tasca ◽  
Riccarda Antiochia

The development of new nanomaterials is gaining increasing attention due to their extensive applications in fields ranging from medicine to food and cultural heritage. Green nanoparticles provide advantages compared to conventional nanoparticles as their synthesis is environmentally-friendly and does not require the use of high temperatures, pressure, or toxic chemicals. In this paper, green silver nanoparticles (AgNPs) have been synthesized according to a new method using quercetin as a reducing agent at room temperature. The synthesized AgNPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS) techniques and successively tested for biocide activity by studying their effects in the inhibition of bacterial growth. The results demonstrated that the smaller the AgNPs size, the greater their biocide activity. In particular, AgNPs with a diameter of 8 nm showed a minimum inhibitory concentration (MIC) value of 1.0 μg/mL against Streptococcus sp., Escherichia coli and Candida sp. microorganisms, while AgNPs with a larger diameter of about 20 nm were able to inhibit microbial of all selected pathogens at a higher MIC value of 2.5 μg/mL.


2016 ◽  
Vol 4 (3) ◽  
pp. 254-258 ◽  
Author(s):  
Mona Hussein Ibraheim ◽  
A.A. Ibrahiem ◽  
T. R. Dalloul

Green synthesis of silver nanoparticles (AgNPs) from silver nitrate was carried out using aqueous Pomegranate juice extract (PJE) as a reducing agent. The formation of AgNPs was characterized by UV-visible (UV–vis) spectroscopy, transmission electron microscopy (TEM), Fourier transforms infrared spectroscopy and X-ray diffraction (XRD). Surface Plasmon resonance (SPR) of ∼420-423 nm confirmed the earlier formation of AgNPs. TEM and XRD analysis showed that the AgNPs with an average diameter of 23 nm are crystalline in nature and have face-centered cubic geometry. The antibacterial efficiency of AgNPs against Escherchia coli and Staphylococcus aureus showed high level of inhibition. Further, the zone of inhibition increased with the increase in the concentration of silver nanoparticles. These studies are quite useful as it shows the utility of green nanotechnology for the synthesis of silver nanoparticles without any toxic residuals and byproducts. The efficient antimicrobial activity of biosynthesized AgNPs proves the application potential in the area of nano-medicine.Int J Appl Sci Biotechnol, Vol 4(3): 254-258


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Oluwole S. Aremu ◽  
T. Qwebani-Ogunleye ◽  
Lebogang Katata-Seru ◽  
Zimbili Mkhize ◽  
John F. Trant

AbstractRespiratory tract infections arise due to the introduction of microbes into the airway, disrupting the normal, healthy, complex interdependent microbiome. The selective disruption of this community can be either beneficial or dangerous. Nanoparticles are a potential tool for modifying this population. Coated silver nanoparticles (AgNPs) were synthesized using ethanolic extracts of Hypoxis hemerocallidea (EEHH), a Southern African plant used extensively in traditional medicine and the source of many bioactive secondary metabolites. The room temperature reaction between silver nitrate and EEHH forms largely spherical AgNPs with an average diameter of 6–20 nm. These nanoparticles show similar levels of antibacterial activity as the broad-spectrum antibiotic streptomycin against Bacillus cereus, Streptococcus pneumonia, Escherichia coli, Pseudomonas aeuroginosa, and Moraxella catarrhalis. However, the AgNPs synergistically increase the antibacterial activity of streptomycin when they are applied in combination (30–52%). AgNPs are reiterated to be promising dual-function antibiotics, synergistically enhancing activity while also acting as delivery agents for small molecules.


Author(s):  
Joud Jalab ◽  
Adawia Kitaz ◽  
Wassim Abdelwahed ◽  
Rawaa Al- Kayali

Aims: The green synthesis of silver nanoparticles in an eco-friendly, economical and more effective approach using (Acacia cyanophylla, Phlomis syriaca and Scolymus hispanicus) plants extracts and describing their main chemical properties and study the effect of its chemical composition on producing silver nanoparticles. Methodology: In this study, aqueous and ethanolic extracts of the three plants were evaluated for antioxidant activity using 2,2-diphenyl-l-picrylhydrazyl (DPPH) assay, Total polyphenol and flavonoid contents were determined using spectrophotometric method, but  total saponins were determined by weight method, The synthesis of silver nanoparticles was performed by a reduction method using aqueous silver nitrate solution and aqueous extracts of the three plants. Then study its characterization in a number of ways, such as visual inspection, UV-Vis spectroscopy and dynamic light scattering. Results: The results showed that the total phenolic content ranged in extracts between (13.08 ±2.279 to 98.39 ±4.755 mg GAE/g DW). While the total flavonoid contents varied from (19.83 ±2.384 to 121.64 ±6.469 mg RE/g DW. Antioxidant activity was expressed as IC50 and the obtained results ranged from (IC50= 0.027 ±0.00038 to 0.878 ±0.045 mg/ml), the results indicated that the ethanolic Acacia cyanophylla extract from the six examined extracts showed the highest phenolic and flavonoid concentration and strong antioxidant activity. Also, the saponins content in the three plants ranged from (0.46 to 2.53)% and the highest amount of saponins reported in Acacia cyanophylla plant. The silver nanoparticles prepared using Acacia cyanophylla extract have reported visible yellowish brown color formation and the absorption peak at 460 nm indicates the biosynthesis of silver nanoparticles and they have average diameter (134.1) nm and the polydispersity index (PdI) was suitable (0.260). Conclusion: Acacia cyanophylla extract has been considered as the best reducing agent among the selected plant extracts for the preparation of stable colloidal silver nanoparticles, this is due to their high content of flavonoids, phenols and saponins.


Bionatura ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 1340-1345
Author(s):  
Teeba H. Mohammad ◽  
Mohsen H. Risan ◽  
Gamal A. El-Hiti ◽  
Dina S. Ahmed ◽  
Emad Yousif

The current study describes the production of silver nanoparticles (AgNPs) to treat Candida glabrata infections. The method involved incubation of silver nitrate (AgNO3) with Aspergillus terreus using a green and straightforward route. The production of AgNPs was confirmed through a color change from transparent yellow to brown as well as by ultraviolet-visible (UV-VIS) spectroscopy. The surface morphology of AgNPs was assessed using a scanning electron microscope. The antifungal activity of AgNPs against C. glabrata was investigated in the serum of 20 infected mice. The mice were divided into four groups, and the level of cytokines: IL-4 and IFN-γ were examined after 21 days. The atomic force microscopy confirmed that the average diameter of AgNPs was 25.1 nm, which is appropriate for delivering silver nanoparticles to treat animals' infection. The concentration of cytokines IL-4 and IFN-γ were significantly (P < 0.05) higher in the C. glabrata-infected group than in the control group. While the cytokines level remained close to average concentration in mice administrated with AgNPs, such a result was comparable with the fourth group of mice (Candida-treated Aspergillus) after treatment with AgNPs.


2021 ◽  
Author(s):  
Thu Ha Bui ◽  
Ngoc Dai Nghia Tran ◽  
Phung Anh Nguyen ◽  
Nhat Linh Duong ◽  
Van Minh Nguyen ◽  
...  

Abstract A cost-effective and green technique was performed for the synthesis of silver nanoparticles (AgNPs) from a plant resource using Citrus maxima peel (CMP) extract as a reducing agent. The formation of AgNPs was confirmed by UV-Vis Spectroscopy at the wavelength range of 400−500 nm. The optimized conditions for the AgNPs synthesis using CMP extract as a reducing agent were determined. At these conditions, the X-ray diffraction (XRD) and the high-resolution transmission electron microscopy (HRTEM) results revealed the face-centered cubic structure of AgNPs had a highly crystalline with the particle size in a range of 10−20 nm. The Fourier transform infrared spectroscopy (FT-IR) demonstrated the presence of flavonoid, terpenoid, phenolic, and glycosides in phytochemical compositions of CMP extract which can act as the reducing agents for AgNPs formation. The antibacterial effect of the AgNPs was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA) by implementing the minimum inhibitory concentration (MIC), minimum batericidal concentration (MBC), and the zone of inhibition tests. The AgNPs exhibited effective antibacterial activity against bacteria with an average diameter of inhibition zones of 11.7 mm, the MIC of 8.27 µg/mL, and the MBC of the 16.54 µg/mL.


Sign in / Sign up

Export Citation Format

Share Document