scholarly journals Nanostructural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nanosized Particles of Both Starch and Silver

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
A. Hebeish ◽  
M. H. El-Rafie ◽  
M. A. El-Sheikh ◽  
Mehrez E. El-Naggar
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
High Speed ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Nanosized Particles ◽  
High Concentration ◽  
Particle Size Analyzer ◽  
Vis Spectroscopy

Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs) in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nanosized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the colloidal solution of AgNPs coated with alkali dissolved starch was cooled and precipitated using ethanol. The powder precipitate was collected by centrifugation, then washed, and dried; St-AgNPs powder was characterized using state-of-the-art facilities including UV-vis spectroscopy, Transmission Electron Microscopy (TEM), particle size analyzer (PS), Polydispersity index (PdI), Zeta potential (ZP), XRD, FT-IR, EDX, and TGA. TEM and XRD indicate that the average size of pure AgNPs does not exceed 20 nm with spherical shape and high concentration of AgNPs (30000 ppm). The results obtained from TGA indicates that the higher thermal stability of starch coated AgNPS than that of starch nanoparticles alone. In addition to the data obtained from EDX which reveals the presence of AgNPs and the data obtained from particle size analyzer and zeta potential determination indicate that the good uniformity and the highly stability of St-AgNPs).

scholarly journals Biosynthetic potential assessment of four food pathogenic bacteria in hydrothermally silver nanoparticles fabrication

2019 ◽  
Vol 8 (1) ◽  
pp. 629-634 ◽  
Author(s):  
Amir Rahimirad ◽  
Afshin Javadi ◽  
Hamid Mirzaei ◽  
Navideh Anarjan ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pathogenic Bacteria ◽  
Heating Time ◽  
Synthesis Process ◽  
Ag Nps ◽  
Physico Chemical ◽  
Minimum Particle Size ◽  
Particle Size Analyzer

Abstract Silver nanoparticles (Ag NPs) were synthesized using four pathogenic bacterial extracts namely, Bacillus cereus, E. coli, Staphylococcus aureus and Salmonella entericasubsp.enterica. Synthesis process were hydrothermally accelerated using temperature, pressure and heating time of 121°C, 1.5 bar ad 15 min. Physico- chemical characteristics of the fabricated Ag NPs, including, particle size, polydispersity index (PDI), zeta potential, broad emission peak (λmax) and concentration were evaluated using UV-Vis spectrophotometer and dynamic light scattering (DLS) particle size analyzer. Furthermore, main existed functional groups in the provided bacterial extracts were recognized using Fourier transform infrared spectroscopy. The obtained results revealed that two main peaks were detected around 3453 and 1636.5 cm-1, for all bacterial extracts, were interrelated to the stretching vibrations of hydroxyl and amide groups which those had key roles in the reduction of ions and stabilizing of the formed Ag NPs. The results also indicated that, Ag NPs with much desirable characteristics, including minimum particle size (25.62 nm) and PDI (0.381), and maximum zeta potential (-29.5 mV) were synthesized using S. e. subsp. enterica extract. λmax, absorbance and concentration values for the fabricated Ag NPs with this bacterial extract were 400 nm, 0.202% a.u. and 5.87 ppm.

scholarly journals Green Synthesis, Characterization, Antioxidant, Antibacterial and Dye Degradation of Silver Nanoparticles using Combretum indicum Leaf Extract

2021 ◽  
Vol 34 (1) ◽  
pp. 216-222
Author(s):  
Arnannit Kuyyogsuy ◽  
Paweena Porrawatkul ◽  
Rungnapa Pimsen ◽  
Prawit Nuengmatcha ◽  
Benjawan Ninwong ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Dye Degradation ◽  
Sunlight Irradiation ◽  
Particle Size Analyzer ◽  
Vis Spectroscopy ◽  
Edx Analyses ◽  
Aqueous Leaf Extract ◽  
And Staphylococcus Aureus

Silver nanoparticles were synthesized by bioreduction of silver nitrate using the aqueous leaf extract of Combretum indicum (CI-AgNPs). The synthesized CI-AgNPs exhibited a distinct absorption peak at 414 nm in UV-vis spectroscopy. Various parameters such as pH, temperature and time were optimized using spectrophotometry. The particle size of the CI-AgNPs was 48 nm as evaluated from the laser particle size analyzer. The XRD and EDX analyses confirmed the presence of silver in silver nanoparticles. Synthesized CI-AgNPs revealed significant antioxidant, antimicrobial (against Escherichia coli and Staphylococcus aureus) and photocatalytic (against methylene blue under sunlight irradiation) activities. Thus, an eco-friendly method was developed to synthesize silver nanoparticles using the C. indicum leaf extract.

Preparation and characterization of silver nanoparticle-porphyrazine composites

2013 ◽  
Vol 17 (10) ◽  
pp. 928-933
Author(s):  
Altuğ Mert Sevim ◽  
Ayşe Selda Keskin ◽  
Ahmet Gül
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Silver Ions ◽  
Organic Medium ◽  
Nano Particles ◽  
Effective Manner ◽  
Vis Spectroscopy ◽  
One Step

A one step chemical reduction process was used for the preparation of hydrophilic silver nanoparticles ( AgNP ) using silver nitrate, sodiumborohydride and polyvinylpyrolidone as stabilizer. In the case of hydrophobic silver nanoparticles reduced silver ions were stabilized with cetyl trimethylammonium bromide (CTAB). The resultant nano particles were characterized by absoption spectra and their interactions with cationic cobalt (QCoPz) and neutral magnesium (MgPz) porphyrazines in water and in organic medium were investigated by using UV-vis spectroscopy and zeta potential techniques. It is confirmed that both metalloporphyrazine molecules interact with silver nanoparticles in an effective manner. The possible arrangement of the porphyrazines on the surfaces of the hydrophilic and hydrophobic AgNPs has been also discussed according to obtained spectroscopic results. These well-characterized novel AgNP -metalloporphyrazine composites are expected to be useful in optical and catalytic applications.

scholarly journals Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi
Keyword(s):  
Silver Nanoparticles ◽  
Irradiation Time ◽  
Chemical Reduction ◽  
Size Control ◽  
Reduction Process ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Transmission Electron ◽  
Origanum Majorana

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

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 Nanocatalytic Activity of Silver Nanoparticles (Ag-Nps) Fabricated using Camellia sinensis (Linn) Tender Leaf Extract and their Characterization

2020 ◽  
Vol 2 (1) ◽  
pp. 24
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pancreatic Enzyme ◽  
Alpha Amylase ◽  
Assay Method ◽  
Ag Nps ◽  
Visible Absorption ◽  
Biological Reduction ◽  
Vis Spectroscopy ◽  
Uv Visible

Silver nanoparticles (Ag-NPs) were prepared by the biological reduction method. Green tea extract was taken as a reducing and stabilizing agent and silver nitrate as the metal precursor for nanoparticle synthesis. The formation of the silver nanoparticles was monitored visually and using UV-Visible absorption spectroscopy. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, FTIR, Zeta sizer, Zeta potential, and antimicrobial studies. Silver nanoparticles were also subjected to investigate nanocatalytic activity with standard pancreatic alpha-amylase and bacterial amylase enzyme by the DNS assay method. UV-Vis spectroscopy revealed the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 430 nm. Four major functional groups of bio-molecules such as phenol, carboxylic acid, protein, and alkyl group were recorded in FTIR spectra. The size of the nanoparticles ranges between 5nm and 150nm. The average size and size distribution of silver nanoparticles is 59.66nm. The zeta potential of the silver nanoparticle is negatively charged and rendered as a sharp peak at -31.7mV. Antimicrobial activity of silver nanoparticles exhibited the highest inhibition against Gram-negative bacteria than Gram-positive bacteria and yeast pathogens. Starch hydrolysis of Ag-NPs was studied with pancreatic alpha-amylase (tailor made), crude and purified bacterial amylase enzyme. The formation of reducing sugar was increased about 40-fold for a purified enzyme, 11-fold for the pancreatic enzyme, and 6-fold for crude bacterial enzyme incorporated with Ag-NPs over control. The present studies recommended that Ag-NPs have a significant role in the degradation of starch into reducing sugars by acting as a nanocatalyst.

scholarly journals Influence of Physico-Chemical Parameters on the Fabrication of Silver Nanoparticles Using Petrea volubilis L. Stem Broth and Its Anti-Microbial Efficacy

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
N. I. Hulkoti ◽  
T. C. Taranath
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Silver Nitrate ◽  
Microbial Activity ◽  
Contact Time ◽  
Nitrate Concentration ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Silver Nitrate Concentration

In this study we describe the phytofabrication of AgNps through a green route as a cost-effective, instantaneous and an eco-friendly approach using Petrea volubilis L. stem broth. The influence of physico-chemical parameters - contact time, stem broth quantity, pH, temperature, and silver nitrate concentration were studied and optimised to engineer, nanoparticles of diverse sizes. Nanoparticles were characterized by UV-Vis spectroscopy, FTIR, XRD, Zeta potential, EDS, and HRTEM. The characterization using HRTEM showed that, the nanoparticles were spherical and with increase in contact time, stem broth quantity, pH, and temperature, the NPs size minimised whereas escalation in silver nitrate concentration, increased their size. Capping molecules were negatively charged and the NPs were passably stable according to zeta potential readings and they were crystalline as per XRD data. According to FTIR analysis, the bio reduction was attributed to alcohol, ethers, carboxylic acids, and esters. The highest anti-bacterial activity was observed against S. aureus and S. typhi whose ZOI diameter was 13 mm at 100?l in both bacteria. The highest anti-fungal activity of silver nanoparticles was observed against A. flavus whose ZOI diameter was 9 mm at 100?l compared to P. chrysogenum which is 3 mm at 100?l. The stem broth did not show any anti-microbial activity for the microbes. Anti-microbial activity of AgNPs is due to its small size and high surface area. Our findings clearly discloses that sizes of silver nanoparticles can be varied by varying the physico-chemical parameters and the small sized nanoparticles so formed are promising antimicrobial agents and has a great potential in various medical applications.

Synthesis of Uniform and High Density Silver Nanoparticles by using Peltophorum pterocarpum flower Extract

2014 ◽  
Vol 1584 ◽  
Author(s):  
Matheswaran BALAMURUGAN ◽  
Shanmugam SARAVANAN ◽  
Naoki OHTANI
Keyword(s):  
Silver Nanoparticles ◽  
Fourier Transform ◽  
Electron Microscope ◽  
Ultra Violet ◽  
Capping Agent ◽  
Nanosized Particles ◽  
Flower Extract ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ft Ir

ABSTRACTSilver nanoparticle (AgNP) is one of the elegant material because its uses in various fields. In this study, AgNPs have been prepared by using Peltophorum pterocarpum (PP) flower extract as reducing and capping agent and aqueous silver nitrate (aq.AgNO3) as silver precursor. The synthesized nanoparticles were characterized using Ultra Violet - Visible (UV-Vis) spectroscopy, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscopy (FT-IR), which reveals the formation of nanosized particles. The UV-Vis spectrum shows an absorption peak around 430nm. HR-TEM images of AgNPs with clear morphology and well dispersed prepared AgNPs.

scholarly journals Eco-friendly microwave-enhanced green synthesis of silver nanoparticles using Aloe vera leaf extract and their physico-chemical and antibacterial studies

2018 ◽  
Vol 7 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Omid Ahmadi ◽  
Hoda Jafarizadeh-Malmiri ◽  
Naeimeh Jodeiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Exposure Time ◽  
Leaf Extract ◽  
Aloe Vera ◽  
Synthesis Conditions ◽  
Stabilizing Agents ◽  
Microwave Exposure ◽  
Mean Particle Size ◽  
Vis Spectroscopy

Abstract Silver nanoparticles (AgNPs) were synthesized using Aloe vera leaf extract as both reducing and stabilizing agents via microwave irradiation method. The effects of the microwave exposure time and the amount of AgNO3 solution on the mean particle size and concentration of the synthesized AgNPs solution were investigated using response surface methodology. The synthesized AgNPs were characterized by transmission electron microscopy, UV-Vis spectroscopy, and dynamic light scattering. Well-dispersed and spherically fabricated AgNPs with mean particle size (46 nm) and maximum concentration (64 ppm) and zeta potential (+15.5 mV), were obtained at optimal synthesis conditions, using 9 ml of AgNO3 (1 mm) and 0.1 ml of Aloe vera extract during microwave exposure time of 360 s. The antibacterial activity of the synthesized AgNPs was tested using Escherichia coli and Staphylococcus aureus bacteria and the obtained results indicated their significant inhibitory effects against these two Gram-negative and Gram-positive bacteria.

Ampicillin-augmented silver nanoparticles for synergistic antimicrobial response: A promising therapeutic approach

2021 ◽  
Vol 22 ◽  
Author(s):  
Kashan Khan ◽  
Mohd Aamir Qureshi ◽  
Ameer Azam ◽  
Moinuddin ◽  
Javed Musarrat ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Bacterial Infections ◽  
Colloidal Stability ◽  
Resistant Bacteria ◽  
Antimicrobial Drugs ◽  
Vis Spectroscopy ◽  
Microbial Infections ◽  
Ft Ir

Aims: Globally Scientists are working to find more efficient antimicrobial drugs to treat microbial infections and kill drug-resistant bacteria. Background: Despite the availability of numerous antimicrobial drugs bacterial infections still poses a serious threat to global health. Due to a constant decline in the effectiveness of antibiotics owing to their repeated exposure as well as shortlasting antimicrobial activity, led to the demand for developing novel therapeutic agents capable of controlling microbial infections. Objective: In this study, we report antimicrobial activity of chemically synthesized silver nanoparticles (cAgNPs) augmented with ampicillin (amp) in order to increase antimicrobial response against Escherichia coli (gram –ve), Staphylococcus aureus (gram +ve) and Streptococcus mutans (gram +ve). Methods: Nanostructure, colloidal stability, morphology and size of cAgNPs before and after functionalization were explored by UV-vis spectroscopy, FT-IR, zeta potential and TEM. The formation and functionalization of cAgNPs was confirmed from UV-vis spectroscopy and FT-IR patterns. From TEM the average sizes of cAgNPs and cAgNP-amp were found to be 13 and 7.8 nm respectively, and change in colloidal stability after augmentation was confirmed from zeta potential values. The antimicrobial efficacies of cAgNP-amp and cAgNPs against E. coli S. aureus and S. mutans were studied by determining minimum inhibitory concentrations (MICs), zone of inhibition, assessment of viable and non-viable bacterial cells and quantitative assessment of biofilm. Results & Discussion: Our results revealed cAgNP-amp to be highly bactericidal compared to cAgNPs or amp alone. The nano-toxicity studies indicated cAgNP-amp to be less toxic compared to cAgNPs alone. Results: This study manifested that cAgNPs show synergistic antimicrobial effect when they get functionalized with amp suggesting their application in curing long-term bacterial infections.

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