Polydisperse Low Diameter ‘Non-Toxic’ Silver Nanoparticles Encapsulated by Rooibos Tea Templates

Nano Hybrids ◽  
2014 ◽  
Vol 8 ◽  
pp. 57-72 ◽  
Author(s):  
M.O. Oyagi ◽  
Immaculate N. Michira ◽  
P. Guto ◽  
P.G.L. Baker ◽  
G. Kamau ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Outer Region ◽  
Colour Change ◽  
Extraction Temperature ◽  
Rooibos Tea ◽  
Vis Spectroscopy ◽  
The Face ◽  
Tunnelling Microscopy ◽  
C 30 ◽  
C 50

This work reports the synthesis of ‘non-toxic’ polydisperse, low diameter silver nanoparticles (AgNPs). Rooibos extracts at temperatures 25 °C, 30 °C, 50 °C, 70 °C and 90 °C were used. The effect of different extraction temperature on the % yield and nature of the AgNPs were investigated. The characteristics of the ‘green synthesis’ processed AgNPs were evaluated through UV-Vis spectroscopy, high resolution tunnelling microscopy (HRTEM), X-ray diffraction (XRD) and EDX techniques. Results indicated an increase in extraction temperature leads to more polyphenol extraction, increase in the AgNP % yield and greater absorbance. A yellow to brown to dark brown colour change observed during the synthesis indicated AgNPs formation. UV-Vis results indicated the AgNPs surface plasmon peaks at 440, 447, 450, 460 and 489 nm for the 25 °C, 30 °C, 50 °C, 70 °C, 90 °C respectively. SEM results revealed spherical nanosized particles with dense cores and lighter outer region with mean diameters for AgNPs ranged between 4.4-5.8 nm. EDX results indicated prominent Ag peaks at 3.10 keV. XRD results showed vaguely defined amorphous polyol peaks at below 2θ = 27°. The sharp peaks at 2θ = 38°, 45°, 66° and 77° which were assigned as 111, 200, 220 and 321 corresponded to the face-centred cubic crystalline silver phase.

Facile Synthesis of Silver Nanoparticles by Chemical Reduction Route

2013 ◽  
Vol 756 ◽  
pp. 99-105
Author(s):  
Rajasingam Ratnamalar ◽  
Mustapha Mariatti ◽  
Zulkifli Ahmad ◽  
Sharif Zein Sharif Hussein
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Chemical Reduction ◽  
Facile Synthesis ◽  
Cubic Lattice ◽  
Vis Spectroscopy ◽  
Simple Chemical ◽  
The Face ◽  
Fine Control ◽  
Xrd Patterns

This work reports a simple chemical reduction route for the preparation of uniformed Ag nanoparticles whereby a fine control over the sizes of the Ag nanoparticles was studied by varying the concentrations of the reducing agents used. In characterization, UV-Vis spectroscopy showed the changes in optical properties of the Ag nanoparticles with regards to their sizes, where as the XRD patterns of the synthesized Ag nanoparticles confirmed the distinct peaks approximately at 2θ = 38.1°, 44.3°, 64.4°, 77.4°, and 81.5 representing Bragg’s reflections from (111), (200), (220), (311), and (222) planes of the face centred cubic lattice phase. This route of synthesis is feasible to produce Ag nanoparticles with diameters in the range of 30-45 nm.

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 Biosynthesis and characterization of silver nanoparticles using ginger spent and their antibacterial activity

2021 ◽  
pp. 174-179
Author(s):  
Sinthia Ganesan ◽  
Palanichamy Mehalingam ◽  
Govindan Sadasivam Selvam
Keyword(s):  
Silver Nanoparticles ◽  
Waste Product ◽  
Colour Change ◽  
Zingiber Officinale ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Diffusion Method ◽  
Klebsiella Pneumonia ◽  
Gram Positive Bacteria ◽  
Vis Spectroscopy

Ginger spent is the byproduct of spice industries that remove the essential oils of ginger (Zingiber officinale) for food industry and medicinal purposes. Ginger is a well known spice used often for seasoning in Indian cuisine. The de-oiled ginger has no specific use mostly goes to waste. Hence, we utilized this industrial waste product in the efficient synthesis of silver nanoparticles with the aid of UV irradiation from a solution of 1mM silver nitrate and spent extract in the ratio 9:1. Immediate colour change from pale yellow to dark brown was noted indicating the rapid synthesis of silver nanoparticles. These nanoparticles were centrifuged, dried and well characterized. UV Vis Spectroscopy, XRD analysis, Zeta potential and SEM analysis was carried out. It was commendable that the size of the nanoparticles fell well within the upper limit of 100nm. Agar well diffusion method was used to screen the antimicrobial activity of the well characterized silver nanoparticles. They were tested against seven pathogenic strains of three gram negative bacteria (Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) three gram positive bacteria(Bacillus subtilis, Staphylococcus aureus and Streptococcus faecalis) and a fungus (Candida  albicans). It was seen that the zone of inhibition(ZOI) in well plate method  increased on increasing the concentration of silver nanoparticles. Further studies could lead to the application of these silver nanoparticles in medicine.

scholarly journals Biosynthesis, characterization and anti-dengue vector activity of silver nanoparticles prepared from Azadirachta indica and Citrullus colocynthis

2020 ◽  
Vol 7 (9) ◽  
pp. 200540
Author(s):  
Shafqat Rasool ◽  
Muhammad Akram Raza ◽  
Farkhanda Manzoor ◽  
Zakia Kanwal ◽  
Saira Riaz ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Azadirachta Indica ◽  
Citrullus Colocynthis ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
The Face ◽  
Vector Activity ◽  
Average Size

We report here biosynthesis of silver nanoparticles (AgNPs) using aqueous extracts of (i) Azadirachta indica leaves and (ii) Citrullus colocynthis fruit and their larvicidal activity against Aedes aegypti. The UV–Vis spectroscopy absorption peaks occurred in the range of 412–416 nm for A. indica AgNPs and 416–431 nm for C. colocynthis AgNPs indicating the silver nature of prepared colloidal samples. The scanning electron microscopy examination revealed the spherical morphology of both types of NPs with average size of 17 ± 4 nm ( A. indica AgNPs) and 26 ± 5 nm ( C. colocynthis AgNPs). The X-ray diffraction pattern confirmed the face-centred cubic (FCC) structure with crystallite size of 11 ± 1 nm ( A. indica AgNPs) and 15 ± 1 nm ( C. colocynthis AgNPs) while characteristic peaks appearing in Fourier transform infrared spectroscopy analysis indicated the attachment of different biomolecules on AgNPs. The larvicidal activity at different concentrations of synthesized AgNPs (1–20 mg l −1 ) and extracts (0.5–1.5%) against Aedes aegypti was examined for 24 h. A concentration-dependent larvicidal potential of both types of AgNPs was observed. The LC 50 values were found to be 0.3 and 1.25 mg l −1 for C. colocynthis AgNPs and A. indica AgNPs, respectively. However, both extracts did not exhibit any notable larvicidal activity.

scholarly journals Green synthesis of silver nanoparticles using Calotropis gigantea and its characterization using UV-Vis Spectroscopy

2022 ◽  
Vol 951 (1) ◽  
pp. 012090
Author(s):  
P Kemala ◽  
R Idroes ◽  
K Khairan ◽  
T E Tallei ◽  
M Ramli ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Synthesis Method ◽  
Colour Change ◽  
Synthesis Methods ◽  
Phytochemical Analysis ◽  
Geothermal Area ◽  
Calotropis Gigantea ◽  
Yellow Solution ◽  
Vis Spectroscopy

Abstract The use of Calotropis gigantea from Ie Seu-Um, Aceh Besar geothermal area for silver nanoparticles (AgNPs) synthesized has been reported. The process of synthesis AgNPs can be carried out with chemical methods, physical methods, and green synthesis methods, but in this study, the process is focused on the green synthesis method using C. gigantea flowers and leaves extract from Ie Seu-Um geothermal area, Aceh Besar. Phytochemical analysis showed that C. gigantea leaves contain alkaloids, steroids, tannins, phenolics, and saponins, while the flowers of C. gigantea contain alkaloids, terpenoids, steroids, flavonoids, tannins, phenolics, and saponins. The reaction of the AgNPs formation was observed by colour change formed. AgNPs-C. gigantea flower extract dan AgNPs-C. gigantea leaves extract showed the reddish-brown and brownish-yellow solution respectively after 48 h incubation in dark condition at room temperature. The result of the reaction characterized using UV-Vis Spectrophotometry showed that the phenomenon of Surface plasmone resonance (SPR) occurs in the mixture of nanoparticles formed. The concentration of AgNO3 as a reagent affected the SPR phenomenon. The result showed that particles formed are the same size and shape.

scholarly journals Green Synthesis and Antimicrobial Activities of Silver Nanoparticles using Cell Free-Extracts of Enterococcus species

2017 ◽  
Vol 9 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Iyabo C. OLADIPO ◽  
Agbaje LATEEF ◽  
Musibau A. AZEEZ ◽  
Tesleem B. ASAFA ◽  
Taofeek A. YEKEEN ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Antimicrobial Activities ◽  
Fermented Foods ◽  
Enterococcus Species ◽  
Selected Area Electron Diffraction ◽  
Inhibition Of Growth ◽  
Vis Spectroscopy ◽  
The Face ◽  
Biosynthesized Agnps

Cell-free extracts of six strains of Enterococcus species obtained from fermented foods were used for the green synthesis of silver nanoparticles (AgNPs), which was characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The biosynthesized AgNPs were dark brown in colour having surface plasmon resonance in the range of 420-442 nm. The spherical shaped AgNPs had sizes of 4-55 nm, whose formations were facilitated by proteins as indicated by the presence of peaks 1,635-1,637 and 3,275-3,313 cm-1 in the FTIR spectra. The energy dispersive x-ray (EDX) showed prominent presence of silver in the AgNPs colloidal solution, while the selected area electron diffraction was typified by the face-centred crystalline nature of silver. The particles inhibited the growth of multi-drug resistant clinical isolates of Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris, and also potentiated the activities of ampicillin, ciprofloxacin and cefuroxime in the AgNPs-antibiotic synergy studies. In addition, the prospective relevance of the particles as nanopreservative in paints was demonstrated with the inhibition of growth of Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus niger and A. flavus in AgNPs-paint admixture. This report further demonstrates the green synthesis of AgNPs by strains of Enterococcus species.

Green and Simple Synthesis of Silver Nanoparticles by Aqueous Extract of Perovskia abrotanoides: Characterization, Optimization and Antimicrobial Activity

2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Plant Extract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Extraction Temperature ◽  
Silver Particles ◽  
Silver Nps ◽  
Perovskia Abrotanoides

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

scholarly journals Silver Nanoparticles Functionalized by Fluorescein Isothiocyanate or Rhodamine B Isothiocyanate: Fluorescent and Plasmonic Materials

2021 ◽  
Vol 11 (6) ◽  
pp. 2472
Author(s):  
Ilaria Fratoddi ◽  
Chiara Battocchio ◽  
Giovanna Iucci ◽  
Daniele Catone ◽  
Antonella Cartoni ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Transient Absorption ◽  
Fluorescein Isothiocyanate ◽  
Dye Molecules ◽  
Chemical Surface ◽  
Vis Spectroscopy ◽  
Rhodamine B Isothiocyanate ◽  
Fluorescent Molecules

This paper presents the synthesis of silver nanoparticles (AgNPs) functionalized with fluorescent molecules, in particular with xanthene-based dyes, i.e., fluorescein isothiocyanate (FITC, λmax = 485 nm) and rhodamine B isothiocyanate (RITC, λmax = 555 nm). An in-depth characterization of the particle–dye systems, i.e., AgNPs–RITC and AgNPs–FITC, is presented to evaluate their chemical structure and optical properties due to the interaction between their plasmonic and absorption properties. UV–Vis spectroscopy and the dynamic light scattering (DLS) measurements confirmed the nanosize of the AgNPs–RITC and AgNPs–FITC. Synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS) was used to study the chemical surface functionalization by structural characterization, confirming/examining the isothiocyanate–metal interaction. For AgNPs–RITC, in which the plasmonic and fluorescence peak are not superimposed, the transient dynamics of the dye fluorescence were also studied. Transient absorption measurements showed that by exciting the AgNPs–RITC sample at a wavelength corresponding to the AgNP plasmon resonance, it was possible to preferentially excite the RITC dye molecules attached to the surface of the NPs with respect to the free dye molecules in the solution. These results demonstrate how, by combining plasmonics and fluorescence, these AgNPs can be used as promising systems in biosensing and imaging applications.

scholarly journals Green synthesis of silver nanoparticles: Characterization and its potential biomedical applications

2021 ◽  
Vol 10 (1) ◽  
pp. 412-420
Author(s):  
Mona S. Alwhibi ◽  
Dina A. Soliman ◽  
Manal A. Awad ◽  
Asma B. Alangery ◽  
Horiah Al Dehaish ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Aloe Vera ◽  
Inhibition Zone ◽  
Biologically Active ◽  
Noble Metal Nanoparticles ◽  
Biological Synthesis ◽  
Ag Nps ◽  
Mouse Melanoma ◽  
Therapeutic Benefits ◽  
Vis Spectroscopy

Abstract In recent times, research on the synthesis of noble metal nanoparticles (NPs) has developed rapidly and attracted considerable attention. The use of plant extracts is the preferred mode for the biological synthesis of NPs due to the presence of biologically active constituents. Aloe vera is a plant endowed with therapeutic benefits especially in skincare due to its unique curative properties. The present study focused on an environmental friendly and rapid method of phytosynthesis of silver nanoparticles (Ag-NPs) using A. vera gel extract as a reductant. The synthesized Ag-NPs were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier transform infrared (FTIR), and dynamic light scattering (DLS). TEM micrographs showed spherical-shaped synthesized Ag-NPs with a diameter of 50–100 nm. The UV-Vis spectrum displayed a broad absorption peak of surface plasmon resonance (SPR) at 450 nm. The mean size and size distribution of the formed Ag-NPs were investigated using the DLS technique. Antibacterial studies revealed zones of inhibition by Ag-NPs of A. vera (9 and 7 mm) against Pseudomonas aeruginosa and Escherichia coli, respectively. Furthermore, the antifungal activity was screened, based on the diameter of the growth inhibition zone using the synthesized Ag-NPs for different fungal strains. Anticancer activity of the synthesized Ag-NPs against the mouse melanoma F10B16 cell line revealed 100% inhibition with Ag-NPs at a concentration of 100 µg mL−1. The phytosynthesized Ag-NPs demonstrated a marked antimicrobial activity and also exhibited a potent cytotoxic effect against mouse melanoma F10B16 cells. The key findings of this study indicate that synthesized Ag-NPs exhibit profound therapeutic activity and could be potentially ideal alternatives in medicinal applications.

scholarly journals Green Synthesis and Characterization of Pullulan Mediated Silver Nanoparticles through Ultraviolet Irradiation

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2382 ◽  
Author(s):  
Muhammad Jamshed Khan ◽  
Suriya Kumari ◽  
Kamyar Shameli ◽  
Jinap Selamat ◽  
Awis Qurni Sazili
Keyword(s):  
Silver Nanoparticles ◽  
Uv Irradiation ◽  
Irradiation Time ◽  
Edible Films ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Vis Spectroscopy ◽  
Face Centered ◽  
Average Lattice

Nanoparticles (NPs) are, frequently, being utilized in multi-dimensional enterprises. Silver nanoparticles (AgNPs) have attracted researchers in the last decade due to their exceptional efficacy at very low volume and stability at higher temperatures. Due to certain limitations of the chemical method of synthesis, AgNPs can be obtained by physical methods including sun rays, microwaves and ultraviolet (UV) radiation. In the current study, the synthesis of pullulan mediated silver nanoparticles (P-AgNPs) was achieved through ultraviolet (UV) irradiation, with a wavelength of 365 nm, for 96 h. P-AgNPs were formed after 24 h of UV-irradiation time and expressed spectra maxima as 415 nm, after 96 h, in UV-vis spectroscopy. The crystallographic structure was “face centered cubic (fcc)” as confirmed by powder X-ray diffraction (PXRD). Furthermore, high resolution transmission electron microscopy (HRTEM) proved that P-AgNPs were covered with a thin layer of pullulan, with a mean crystalline size of 6.02 ± 2.37. The average lattice fringe spacing of nanoparticles was confirmed as 0.235 nm with quasi-spherical characteristics, by selected area electron diffraction (SAED) analysis. These green synthesized P-AgNPs can be utilized efficiently, as an active food and meat preservative, when incorporated into the edible films.

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