scholarly journals pH effect on the synthesis of different size silver nanoparticles evaluated by DLS and their size-dependent antimicrobial activity

2020 ◽  
Vol 25 (4) ◽  
Author(s):  
Leiriana Aparecida Pinto Gontijo ◽  
Ellen Raphael ◽  
Daniela Pereira Santos Ferrari ◽  
Jefferson Luis Ferrari ◽  
Juliana Pereira Lyon ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Size Distribution ◽  
Colloidal Stability ◽  
Chemical Reduction ◽  
Ph Effect ◽  
Antimicrobial Properties ◽  
Size Dependent

ABSTRACT This paper reports citrate-stabilized silver nanoparticles (AgNPs) synthesized by nitrate ion chemical reduction with sodium borohydride, at different pHs (2–9). The AgNPs synthesized by this method exhibited size distribution from 5 to 249 nm, depending on pH, as determined by dynamic light scattering, and morphology spherical, as determined by transmission electron microscopy. In pH range 3–7 occurred aggregation of the nanoparticles. The size distribution depending on pH was determined by dynamic light scattering. The zeta potential was determined, and the colloidal stability was correlated with nanoparticles aggregation at different pHs. The size-dependent antimicrobial activity was evaluated for two solutions, wherein both samples exhibited antimicrobial activity, although the smallest AgNPs without agglomeration have enhanced antimicrobial properties.

Interactive influence of extracellular polymeric substances (EPS) and electrolytes on the colloidal stability of silver nanoparticles

2020 ◽  
Vol 7 (1) ◽  
pp. 186-197 ◽  
Author(s):  
Ishara Fernando ◽  
Dan Lu ◽  
Yan Zhou
Keyword(s):  
Silver Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Electrophoretic Mobility ◽  
Extracellular Polymeric Substances ◽  
Colloidal Stability ◽  
Time Resolved

The colloidal stability of silver nanoparticles (AgNPs) was evaluated using time-resolved dynamic light scattering, electrophoretic mobility and dissolved Ag concentration in the presence of electrolytes and extracellular polymeric substances (EPS).

scholarly journals Enhanced Antibacterial and Antioxidant Properties of Chitosan Films Blended with Gallic Acid and Incorporated with Thymol Silver Nanoparticles

2021 ◽  
Vol 11 (6-S) ◽  
pp. 53-69
Author(s):  
Bipin Lade ◽  
Akash Kamdi ◽  
Arti Shanware
Keyword(s):  
Antimicrobial Activity ◽  
Wound Healing ◽  
Silver Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Gallic Acid ◽  
Antioxidant Properties ◽  
Surface Charges ◽  
Vis Spectroscopy ◽  
Chitosan Films

In the present study, an attempt has been made to build and evaluate Chitosan+Glycerol/Gallic acid/Thymol-silver nanoparticles or chitosan blended (C+G/GA/T-SNPs) film to significantly improve antioxidant and antibacterial activity for accelerated wound healing. Methanolic Gallic acid is used for the first time in antibacterial chitosan control (C+G) films. All developed films, compounds was Thymol and Gallic acid and their synthesized Thymol silver nanoparticles (T-SNPs) and Gallic acid silver nanoparticles (GA-SNPs) were characterized by Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-Ray diffraction (XRD), Zeta potential (ZP), Dynamic light scattering (DLS), and UV-Vis spectroscopy. T-SNPs and GA-SNPs are rod and spherical in shape and were sufficient to reduce, capped, and stabilize. T-SNPs and GA-SNPs were measured Dynamic Light scattering and found to be 123.2 nm and 121.1 nm with surface charges of -19.7 and -20.3 respectively. The incorporation of methanolic Gallic acid and T-SNPs into chitosan films, as predicted, effectively enhanced antioxidant and antimicrobial activity. The antimicrobial activity of Thymol, T-SNPs and C+G/GA/T-SNPs film showed more zone of inhibition than Gallic acid, GA-SNPs and C+G film. The elasticity, texture and folding endurance of the C+G film and C+G/GA/T-SNPs films have been substantially improved. The ecological quality of the generated C+G and C+G/GA/T-SNPs film was determined by the assessment of soil degradation and water degradation parameters. These findings lead to the conclusion that the C+G/GA/T-SNPs film produced with Gallic acid and T-SNPs can improve wound healing. Keywords: Chitosan, Gallic Acid, Thymol Silver Nanoparticles, Antibacterial and Antioxidant Properties.

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. 

pH effect on the aggregation of silver nanoparticles synthesized by chemical reduction

2014 ◽  
Vol 32 (1) ◽  
pp. 107-111 ◽  
Author(s):  
M. K. Alqadi ◽  
O. A. Abo Noqtah ◽  
F. Y. Alzoubi ◽  
J. Alzouby ◽  
K. Aljarrah
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Ph Effect

scholarly journals PEGylation of Superparamagnetic Iron Oxide Nanoparticles with Self-Organizing Polyacrylate-PEG Brushes for Contrast Enhancement in MRI Diagnosis

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 776 ◽  
Author(s):  
Erzsébet Illés ◽  
Márta Szekeres ◽  
Ildikó Tóth ◽  
Katalin Farkas ◽  
Imre Földesi ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Colloidal Stability ◽  
Serum Proteins ◽  
Electrokinetic Potential ◽  
Blood Compatibility ◽  
Superparamagnetic Iron Oxide ◽  
Protein Corona ◽  
Superparamagnetic Nanoparticles ◽  
Mri Diagnosis

For biomedical applications, superparamagnetic nanoparticles (MNPs) have to be coated with a stealth layer that provides colloidal stability in biological media, long enough persistence and circulation times for reaching the expected medical aims, and anchor sites for further attachment of bioactive agents. One of such stealth molecules designed and synthesized by us, poly(polyethylene glycol methacrylate-co-acrylic acid) referred to as P(PEGMA-AA), was demonstrated to make MNPs reasonably resistant to cell internalization, and be an excellent candidate for magnetic hyperthermia treatments in addition to possessing the necessary colloidal stability under physiological conditions (Illés et al. J. Magn. Magn. Mater. 2018, 451, 710–720). In the present work, we elaborated on the molecular background of the formation of the P(PEGMA-AA)-coated MNPs, and of their remarkable colloidal stability and salt tolerance by using potentiometric acid–base titration, adsorption isotherm determination, infrared spectroscopy (FT-IR ATR), dynamic light scattering, and electrokinetic potential determination methods. The P(PEGMA-AA)@MNPs have excellent blood compatibility as demonstrated in blood sedimentation, smears, and white blood cell viability experiments. In addition, blood serum proteins formed a protein corona, protecting the particles against aggregation (found in dynamic light scattering and electrokinetic potential measurements). Our novel particles also proved to be promising candidates for MRI diagnosis, exhibiting one of the highest values of r2 relaxivity (451 mM−1s−1) found in literature.

Dynamic light scattering detection of silver nanoparticles, food pathogen bacteria and their bactericidal interactions

2021 ◽  
Vol 18 (8) ◽  
pp. 086002
Author(s):  
A A Nastulyavichus ◽  
S I Kudryashov ◽  
E R Tolordava ◽  
L F Khaertdinova ◽  
Yu K Yushina ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Light Scattering Detection ◽  
Food Pathogen

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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