scholarly journals Silver Nanoparticles Obtained by Semicontinuous Chemical Reduction Using Carboxymethyl Cellulose as a Stabilizing Agent and Its Antibacterial Capacity

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
M. A. Pedroza-Toscano ◽  
S. López-Cuenca ◽  
M. Rabelero-Velasco ◽  
E. D. Moreno-Medrano ◽  
A. P. Mendizabal-Ruiz ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Carboxymethyl Cellulose ◽  
Chemical Reduction ◽  
Weight Ratio ◽  
Visible Spectrum ◽  
Reducing Agent ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Vis Spectroscopy

Preparation of silver nanoparticles was carried out by semicontinuous reduction of Ag+ ions at low temperatures. Silver nitrate was used as the Ag0 precursor, the carboxymethyl cellulose (CMC) as stabilizer and primary reducing agent, and sodium borohydride as reducing agent. Weight ratios of 1 : 1 and 1 : 2 of AgNO3 : CMC were used for carrying out the reactions. Silver nanoparticles were characterized by UV-VIS spectroscopy, transmission electronic microscopy (TEM), and X-ray diffraction (XRD). The formation of silver nanoparticles was confirmed by XRD spectroscopy and by the presence of an absorption peak around 400 nm in the UV-visible spectrum. Unimodal size distributions of spheroidal nanoparticles were observed by TEM. Greater productivities than those reported by other authors were obtained with the advantage of using a lower temperature and minor reaction times. By using a higher CMC/AgNO3 weight ratio or a higher concentration of AgNO3, AgNPs with larger average size were produced. Antibacterial activity of AgNPs against S. aureus and E. coli was determined by the agar disk diffusion method. The higher the AgNPs concentration, the larger the inhibition zone. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus and E. coli was 5 μg/disk.

Biological Applications, Green Synthesis, Characterization of Silver Nanoparticles (AgNPs) Using Artemisia annua L.

2021 ◽  
Vol 13 (7) ◽  
pp. 1304-1309
Author(s):  
Hamed A. Ghramh ◽  
Rahmah N. Al-Qthanin ◽  
Zubair Ahmad ◽  
Essam H. Ibrahim ◽  
Mona Kilany ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Artemisia Annua ◽  
Diffusion Method ◽  
Biological Applications ◽  
Disk Diffusion Method ◽  
Vis Spectroscopy ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

ABSTRACTThis article reports on the silver nanoparticles (AaAgNPs) that were green-synthesized by using Artemisia annua L. extract (AaExt) and their collective biological applications. Active biomolecules in the extract and extract containing AgNPs were characterized using Fourier-transform-infrared-spectroscopy (FTIR) and AgNPs were monitored by UV/vis spectroscopy and SEM (scanning electron microscopy) analysis. The size of the particle is around 100 nm. The antibacterial activity was measured by the disk diffusion method against the Gram-negative/positive pathogenic bacteria. The extract and extract containing AgNPs showed a significant antibacterial activity. Cytotoxic potential of the synthesized AgNPs was analyzed against the rat splenocytes. The results showed that there were cytotoxic effects of A. annua leaves extract but stimulatory effects when the extract contained AgNPs on normal splenocytes. Extract of A. annua showed very little increase in liver enzymes. Regarding the larvicidal activity, the extract containing AgNPs was more effective than the crude leaves extract against 4th instar larvae of Culex pipiens (LC50 = 171.378 ppm) compared to the plant extract (LC50 = 5389.726 ppm) by about 31.449 folds.

scholarly journals Optimization of antimicrobial efficiency of silver nanoparticles against three oral microorganisms in irreversible hydrocolloid impressions

2021 ◽  
Author(s):  
Ahmad Jafari ◽  
Ramin Mazaheri Nezhad Fard ◽  
Sima Shahabi ◽  
Farid Abbasi ◽  
Golshid Javdani Shahedin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Ag Nps ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Irreversible Hydrocolloid ◽  
Predicted Model ◽  
Water Ratio

Background and Objectives: Silver nanoparticles (Ag-NPs) are potent antimicrobial agents, which have recently been used in dentistry. The aim of the current study was to optimize antimicrobial activity of Ag-NPs used in preparing irre- versible hydrocolloid impressions against three microorganisms of Escherichia coli, Streptococcus mutans and Candida albicans. Materials and Methods: After assessing antimicrobial activity of the compound using disk diffusion method, three parame- ters of concentration of Ag-NPs (250-1000 ppm), ratio of hydrocolloid impression material powder to water (0.30-0.50) and time of mixing (20.0-60.0 s), affecting antimicrobial activity of irreversible hydrocolloid impression materials against the three microorganisms, were optimized. This combined process was successfully modeled and optimized using Box-Behnken design with response surface methodology (RSM). Decreases in colony number of E. coli, S. mutans and C. albicans were proposed as responses. Results: Qualitative antimicrobial assessments respectively showed average zone of inhibition (ZOI) of 3.7 mm for E. coli, 3.5 mm for S. mutans and 4 mm for C. albicans. For all responses, when the mixing duration and powder-to-water ratio increased, the circumstances (mixing duration of 59.38 s, powder-to-water ratio of 0.4 and Ag-NP concentration of 992 response) increased. Results showed that in optimum ppm, the proportion of decreases in colony numbers was maximum (89.03% for E. coli, 87.08% for S. mutans and 74.54% for C. albicans). Regression analysis illustrated a good fit of the ex- perimental data to the predicted model as high correlation coefficients validated that the predicted model was well fitted with data. Values of R2Adj with R2Pred were associated to the accuracy of this model in all responses. Conclusion: Disinfection efficiency dramatically increased with increasing of Ag-NP concentration, powder-to-water ratio and mixing time.

scholarly journals BACTERIAL CELLULOSE FROM RICE WASTE WATER AND ITS COMPOSITE WHICH ARE DEPOSITED NANOPARTICLE AS AN ANTIMICROBIAL MATERIAL

2016 ◽  
Vol 12 (1) ◽  
pp. 70 ◽  
Author(s):  
Eli Rohaeti ◽  
Endang W Laksono ◽  
Anna Rakhmawati
Keyword(s):  
Waste Water ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Bacterial Cellulose ◽  
Nitrate Solution ◽  
Diffusion Method ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Chitosan Composite

<pre><span lang="EN-GB">Bacterial cellulose (C) and its composites were synthesized from rice waste water<strong> </strong>with addition of glycerol (G) and chitosan (Ch).</span><strong></strong><span lang="EN-GB">Antibacterial activity of the C, the bacterial cellulose-chitosan composite (CCh), and the bacterial  cellulose – glycerol - chitosan composite (CGCh) which were deposited silver nanoparticles against <em>S. aureus</em>, <em>E.</em> <em>coli</em>,  and yeast <em>C. albicans</em> has been conducted. Silver nanoparticles was prepared by chemical reduction of a silver nitrate solution, a trisodium citrate as a reductor, and a PVA as a stabilizer. The UV-Vis spectroscopy is used to determine the formation of silver nanoparticles. The characterization was conducted on the bacterial celluloses and those composites including the functional groups by the FTIR, the mechanical properties by Tensile Tester, photos surfaces by SEM, and the test of the antibacterial activity against <em>S</em>. <em>aureus</em>, <em>E. coli</em>, and <em>C. albicans</em> by diffusion method. The silver nanoparticle characterization indicates that the silver nanoparticles are formed at a wavelength of 418.80 nm. The antibacterial test showed an inhibitory effect of the C, the CCh, and the CGCh which are deposited  the silver nanoparticles against of <em>S. aureus</em>, <em>E. coli</em>,  and C.albicans. The CGChs which are deposited silver nanoparticles has the highest antimicrobial activity against the <em>Staphylococcus aureus</em> ATCC 25923. The CGs which are deposited silver nanoparticles provide the highest antimicrobial activity against the <em>E. coli</em> ATCC 25922 and the yeast <em>Candida albicans</em> ATCC 10231.</span></pre>

Self-Assembled Synthesis and Characterization of Novel [Co(1-vinylimidazole)6].NO3 Polymer: Highly Efficient Antimicrobial Agent

2021 ◽  
Vol 43 (6) ◽  
pp. 706-706
Author(s):  
Fouzia Chang Fouzia Chang ◽  
Najma Memon Najma Memon ◽  
Shahabuddin Memon Shahabuddin Memon ◽  
Ayaz Ali Memon Ayaz Ali Memon ◽  
Saddam Hussain Bughio Saddam Hussain Bughio ◽  
...  
Keyword(s):  
Cobalt Atom ◽  
Diffusion Method ◽  
Cobalt Metal ◽  
Orthorhombic Unit Cell ◽  
Disk Diffusion Method ◽  
X Ray ◽  
Cell Parameters ◽  
E Coli ◽  
X Ray Crystallography ◽  
Vis Spectroscopy

Cobalt coordination polymer i.e. [Co(1-VI)6]and#183;NO3 was successfully synthesized with cobalt metal and (VI = vinylimidazole) and characterized by elemental analysis, FTIR, UV/Vis spectroscopy and X-ray crystallography. The structure of the compound was determined by single X-ray crystallography at temperature 296 K with a Bruker APEX II CCD diffractometer using Mo-Kα radiations (λ = 0.71073 and#197;), R = 0.0642 and 0.0989. Orthorhombic unit cell parameters are a = 16.1341 (6) and#197;, b = 16.5179(16) and#197;, c = 18.2664(16) and#197;, V= 4868.0 (8) and#197;, Dx = 4, Mr = 937.91. The X-ray crystallography studies showed that the compound is polymeric in nature, in which cobalt atom coordinated with six N atoms of the 1-vinylimidazole ligands in a distorted orthorhombic geometry. As-prepared compound was screened in vitro against a variety of microorganisms, such as Gram-positive (G +ve) Staphylococcusaureus (S. aureus) and Gram-negative (G -ve) Escherichia coli (E. coli) bacterial strains, and fungal species with Aspergillus niger (A. niger) and Rhizopus stolonifer(R.stolonifer)by applying disk diffusion method. MIC (minimum inhibitory concentration) value for prepared [Co(1-VI)6]and#183;NO3 compound is 125 μg.mL-1a this MIC value cobalt polymer showed higher activity against E. coli and S. aureus () as compared to fungi including; R. StoloniferandA. Niger at 125 μg.mL-1).This study helps to reduce the risk of infectious diseases caused by various microorganisms.

scholarly journals Studies on Biosynthesis of Silver Nanoparticles Using Rhizopus sp. and its Antibacterial Efficacy on E. coli MDR Strains

2014 ◽  
Vol 23 ◽  
pp. 27-35
Author(s):  
Jyothi Hiremath ◽  
Vandana Rathod ◽  
Shivaraj Ninganagouda ◽  
Dattu Singh ◽  
K. Prema
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Human Life ◽  
Antibacterial Properties ◽  
Pharmaceutical Products ◽  
Diffusion Method ◽  
Plasmon Resonance Peak ◽  
Synthesis Of Nanoparticles ◽  
E Coli ◽  
Vis Spectroscopy

Nanotechnology is a field that is burgeoning day by day, making an impact in all spheres of human life. Biological methods of synthesis have paved way for the “greener synthesis” of nanoparticles and these have proven to be better methods due to slower kinetics, they offer better manipulation and control over crystal growth and their stabilization. In this context we have investigated extracellular biosynthesis of silver nanoparticles (AgNPs) using cell-free extract of Rhizopus spp.. Formation of AgNPs was indicated by the change in the colour of the cellfree extract from yellow to dark brown under static condition after 48 hrs of incubation. Characterization of AgNPs was carried out by UV-Vis Spectroscopy which gave sharp plasmon resonance peak at 429 nm corresponding to spherical shaped nanoparticles. Transmission electron microscopy (TEM) micrograph showed formation of well-dispersed AgNPs in the range of 25-50 nm. Scanning electron microscopy (SEM) showed the particles to be uniformly dispersed without agglomeration with smooth morphology. EDS showed the presence of elemental silver at 3kev. X-ray diffraction (XRD)-spectrum of the AgNPs exhibited 2θ¸ values corresponding to nanocrystal. These biosynthesized AgNPs were used to study their antimicrobial activity against Multi-drug resistant (MDR) E. coli strains, by Agar diffusion method. Zone of inhibition was measured. Synthesis of nanosized particles with antibacterial properties, which are called "nanoantibiotics", is of great interest in the development of new pharmaceutical products.

scholarly journals Influence of antibiotics and silver nanoparticles on the change of sensitivity of E. coli to antibacterial drugs

2020 ◽  
Vol 50 (2) ◽  
pp. 84-91
Author(s):  
N. N. Shkil ◽  
E. V. Nefedova
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Reference Strain ◽  
Field Isolate ◽  
Antibiotic Sensitivity ◽  
Water Soluble ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antibacterial Drugs ◽  
E Coli

Research has been conducted to evaluate the effect of antibiotics and silver nanoparticles in combination with antibiotics on the change in antibiotic sensitivity to antibacterial drugs of E. coli ATCC 25922 reference strain and its isolate. Nanoparticles obtained by electron beam treatment of aqueous solution containing water-soluble stabilizing polymer and water-soluble silver salt were used in the experiment. During the treatment a beam of accelerated electrons obtained on the installation of a linear accelerator of the ILU-10 type passed through a solution with a working dose of 5–30 kGy ranging in size from 20 to 60 nm. Sensitivity of microorganisms of E. coli ATCC 25922 reference strain and its isolate obtained from cow endometritis to antibacterial substances and their combinations was determined from dilution with a minimum bacteriostatic concentration. The dilution in the amount of 0.2 ml was added to meat-and-peptone agar and the antibiotic sensitivity of microorganisms was determined by the disk diffusion method. Sensitivity to 24 types of antibacterial drugs was tested. Cultivation of E. coli ATCC 25922 with AgNPs in combination with one of the antibiotics (azitronite, amoxicillin, enroflox, ceftiofur, tylosin, cobactan, oxytetracycline) contributed to an increase in the number of drugs (from 14.3 to 57.1%), to which the microorganism was sensitive. Cultivation of the E. coli isolate with 5 (62.5%) of the studied antibiotics led to an increase in resistance from 1 (5.5%) to 3 (16.7%) antibacterial agents. AgNPs in combination with antibiotics azitronite, amoxicillin, enroflox, ceftiofur, tylosin, cobactan, gentamicin, oxytetracycline contributed to a decrease in the resistance of E. coli ATCC 25922 (from 15.4 to 46.1%) and E. coli field isolate (from 16.7 to 37.7%) to antibacterial drugs. The pronounced ability of AgNPs to increase antibiotic sensitivity was established. This was confirmed by the joint cultivation of antibiotics and AgNPs with E. coli ATCC 25922 and field isolate of E. coli, causing an increase in sensitivity and high sensitivity to antibacterial drugs, which was previously absent. The study confirmed the results of research on the ability of nanoparticles of metals of the transition group to affect the sensitivity of microorganisms to antibacterial agents and to restore it.

scholarly journals BACTERIAL CELLULOSE FROM RICE WASTE WATER AND ITS COMPOSITE WHICH ARE DEPOSITED NANOPARTICLE AS AN ANTIMICROBIAL MATERIAL

2016 ◽  
Vol 12 (1) ◽  
pp. 70 ◽  
Author(s):  
Eli Rohaeti ◽  
Endang W Laksono ◽  
Anna Rakhmawati
Keyword(s):  
Waste Water ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Bacterial Cellulose ◽  
Nitrate Solution ◽  
Diffusion Method ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Chitosan Composite

<pre><span lang="EN-GB">Bacterial cellulose (C) and its composites were synthesized from rice waste water<strong> </strong>with addition of glycerol (G) and chitosan (Ch).</span><strong></strong><span lang="EN-GB">Antibacterial activity of the C, the bacterial cellulose-chitosan composite (CCh), and the bacterial  cellulose – glycerol - chitosan composite (CGCh) which were deposited silver nanoparticles against <em>S. aureus</em>, <em>E.</em> <em>coli</em>,  and yeast <em>C. albicans</em> has been conducted. Silver nanoparticles was prepared by chemical reduction of a silver nitrate solution, a trisodium citrate as a reductor, and a PVA as a stabilizer. The UV-Vis spectroscopy is used to determine the formation of silver nanoparticles. The characterization was conducted on the bacterial celluloses and those composites including the functional groups by the FTIR, the mechanical properties by Tensile Tester, photos surfaces by SEM, and the test of the antibacterial activity against <em>S</em>. <em>aureus</em>, <em>E. coli</em>, and <em>C. albicans</em> by diffusion method. The silver nanoparticle characterization indicates that the silver nanoparticles are formed at a wavelength of 418.80 nm. The antibacterial test showed an inhibitory effect of the C, the CCh, and the CGCh which are deposited  the silver nanoparticles against of <em>S. aureus</em>, <em>E. coli</em>,  and C.albicans. The CGChs which are deposited silver nanoparticles has the highest antimicrobial activity against the <em>Staphylococcus aureus</em> ATCC 25923. The CGs which are deposited silver nanoparticles provide the highest antimicrobial activity against the <em>E. coli</em> ATCC 25922 and the yeast <em>Candida albicans</em> ATCC 10231.</span></pre>

BACTERIAL CELLULOSE FROM RICE WASTE WATER AND ITS COMPOSITE WHICH ARE DEPOSITED NANOPARTICLE AS AN ANTIMICROBIAL MATERIAL

2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Eli Rohaeti
Keyword(s):  
Waste Water ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Bacterial Cellulose ◽  
Nitrate Solution ◽  
Diffusion Method ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Chitosan Composite

<pre><span lang="EN-GB">Bacterial cellulose (C) and its composites were synthesized from rice waste water<strong> </strong>with addition of glycerol (G) and chitosan (Ch).</span><strong></strong><span lang="EN-GB">Antibacterial activity of the C, the bacterial cellulose-chitosan composite (CCh), and the bacterial  cellulose – glycerol - chitosan composite (CGCh) which were deposited silver nanoparticles against <em>S. aureus</em>, <em>E.</em> <em>coli</em>,  and yeast <em>C. albicans</em> has been conducted. Silver nanoparticles was prepared by chemical reduction of a silver nitrate solution, a trisodium citrate as a reductor, and a PVA as a stabilizer. The UV-Vis spectroscopy is used to determine the formation of silver nanoparticles. The characterization was conducted on the bacterial celluloses and those composites including the functional groups by the FTIR, the mechanical properties by Tensile Tester, photos surfaces by SEM, and the test of the antibacterial activity against <em>S</em>. <em>aureus</em>, <em>E. coli</em>, and <em>C. albicans</em> by diffusion method. The silver nanoparticle characterization indicates that the silver nanoparticles are formed at a wavelength of 418.80 nm. The antibacterial test showed an inhibitory effect of the C, the CCh, and the CGCh which are deposited  the silver nanoparticles against of <em>S. aureus</em>, <em>E. coli</em>,  and C.albicans. The CGChs which are deposited silver nanoparticles has the highest antimicrobial activity against the <em>Staphylococcus aureus</em> ATCC 25923. The CGs which are deposited silver nanoparticles provide the highest antimicrobial activity against the <em>E. coli</em> ATCC 25922 and the yeast <em>Candida albicans</em> ATCC 10231.</span></pre>

scholarly journals Comparison of the antibacterial activity against Escherichia coli of silver nanoparticle produced by chemical synthesis with biosynthesis

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Nguyen Phuc Quan 1,2 ◽  
Tran Quoc Vinh 1 ◽  
Kieu Thi My Yen 1 ◽  
Le Vu Khanh Trang 2 ◽  
Nguyen Minh Ly 2 ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Color Change ◽  
Chemical Reduction ◽  
Spherical Shape ◽  
Average Diameter ◽  
Ag Nps ◽  
E Coli ◽  
Vis Spectroscopy

The synthesis of silver nanoparticles (Ag NPs) has been carried out using different methods, mainly by biological and chemical methods; however, comparing antibacterial activity of Ag NPs synthesized by these methods has not been conducted before. In this study, silver nanoparticles (Ag NPs) were synthesized by methods using reducing agent NaBH4/carboxymethyl cellulose (CMC) and fungal strain Trichoderma asperellum (T.asperellum). The formation of silver nanoparticles was observed visually by color change and identified by Ultraviolet-visible (UV – vis) spectroscopy. The transmission electron microscopy (TEM) image illustrated almost nanoparticles with spherical shape and average diameter of 4.1 ± 0.2 nm and 2.1 ± 0.2 nm of samples produced from chemical reduction and biosynthesis respectively. Both samples after 180 days storing have been separated lightly, but the agglomeration and absorbance peak shifting were not observed which proved the high stability of synthesized Ag NPs. Antimicrobial activity against human bacterial pathogen Escherichia coli (E. coli) showed that the inhibition zone produced by “biosynthesis” and “chemical reduction” Ag NPs were 3.17 cm and 2.42 cm respectively. With nanoparticles size smaller than 2 mm, antibacterial activity of “biosynthesis” Ag NPs against E. coli was 31 % higher than “chemical reduction” Ag NPs, although the concentration of Ag NPs produced by biosynthesis was about 10-fold less.

Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

2011 ◽  
Vol 4 (3) ◽  
pp. 1491-1496
Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Therapeutic Potential ◽  
Chemical Reduction ◽  
Ultrasonic Field ◽  
Great Promise ◽  
Chemical Reduction Method ◽  
E Coli

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles. 

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