scholarly journals COMPARISON OF SELF-ORGANIZATION PROCESSES IN AQUEOUS SOLUTIONS OF L-CYSTEINE AND N-ACETYL-L-CYSTEINE WITH SILVER NITRITE

2021 ◽  
pp. 56-68
Author(s):  
Татьяна Викторовна Потапенкова ◽  
Дмитрий Викторович Вишневецкий ◽  
Александра Ивановна Иванова ◽  
Светлана Дмитриевна Хижняк ◽  
Павел Михайлович Пахомов
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Light Scattering ◽  
Aqueous Solutions ◽  
Uv Spectroscopy ◽  
Self Organization ◽  
Gel Formation ◽  
Silver Solution ◽  
Scanning Electron

С помощью методов УФ спектроскопии, динамического светорассеяния (ДСР) и сканирующей электронной микроскопии (СЭМ) в водных растворах L-цистеина и N-ацетил-L-цистеина (НАЦ) с нитритом серебра (AgNO) при концентрации от 0.001 М до 0.025 М и различных соотношениях исходных компонентов изучены процессы самоорганизации, приводящие к образованию гидрогеля. Установлено, что для растворов на основе L-цистеин и AgNO (цистеин-серебряный раствор - ЦСР) с концентрацией исходных компонентов 0.025 М и выше образуются устойчивые гидрогели, содержащие наночастицы серебра (НЧС). В то же время, в растворах на основе НАЦ и AgNO гели и НЧС не формировались. Определены закономерности и условия, влияющие на процесс образования геля, что позволило предложить механизм гелеобразования в ЦСР. Using the methods of UV spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM) in aqueous solutions of L-cysteine and N-acetyl-L-cysteine (NAC) add silver nitrite (AgNO) at different concentration from 0.001 to 0.025 M the processes of self-organization leading to the formation of a hydrogel have studied in various ratios of the initial components. It has found that for solutions based on L-cysteine and AgNO (cysteine-silver solution - CSS) with a concentration of initial components of 0.025 M form stable hydrogels containing silver nanoparticles (SNPs). At the same time, solutions based on NAC and AgNO are unable to form gels and SNPs. The regularities and conditions influencing the process of gel formation have been determined, which made it possible to propose a mechanism of gelation in the CSS.

scholarly journals GEL FORMATION IN AQUEOUS SOLUTIONS OF L-CYSTEINE AND SILVER NITRITE

2020 ◽  
pp. 45-53
Author(s):  
Татьяна Викторовна Потапенкова ◽  
Светлана Дмитриевна Хижняк ◽  
Дмитрий Викторович Вишневецкий ◽  
Павел Михайлович Пахомов
Keyword(s):  
Silver Nanoparticles ◽  
Amino Acid ◽  
Aqueous Solutions ◽  
Uv Spectroscopy ◽  
Self Organization ◽  
Gel Formation ◽  
Wide Range ◽  
Dilute Aqueous Solutions

В работе исследованы процессы гелеобразования в разбавленных водных растворах на основе простейшей аминокислоты L-цистеина и нитрита серебра (AgNO). С помощью метода УФ спектроскопии в широком диапазоне концентраций L-цистеина и AgNO в растворе от 0,001 до 0,05 М и различном соотношении L-цистеин/AgNO от 1,0/0,8 до 1,0/1,6. Изучены процессы самоорганизации, приводящие к образованию гидрогеля. Установлено, что для растворов с концентрацией исходных компонентов 0,05 М образуются устойчивые гидрогели, содержащие наночастицы серебра. The work investigated the processes of gelation in dilute aqueous solutions based on the simplest amino acid L-cysteine and silver nitrite (AgNO). The processes were studied using UV spectroscopy in a wide range of concentrations of L-cysteine and AgNO in solution from 0.001 to 0.05 M and various ratios of L-cysteine / AgNO from 1.0 / 0.8 to 1.0 / 1.6. Self-organization leading to the formation of a hydrogel. It was found that stable hydrogels containing silver nanoparticles are formed for solutions with a concentration of initial components of 0.05 M.

scholarly journals GREEN TECHNOLOGY MEDIATED SYNTHESIS OF SILVER NANOPARTICLES FROM MOMORDICA CHARANTIA FRUIT EXTRACT AND ITS BACTERICIDAL ACTIVITY

2017 ◽  
Vol 10 (3) ◽  
pp. 196 ◽  
Author(s):  
S C Joshi ◽  
Utkarsh Kaushik ◽  
Aproova Upadhyaya ◽  
Priyanka Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Atomic Force Microscope ◽  
Momordica Charantia ◽  
Diffusion Method ◽  
Fruit Extract ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Scanning Electron

ABSTRACTObjective: The synthesis of nanoparticles from biological processes is evolving a new era of research interests in nanotechnology. Silver nanoparticlesare usually synthesized by chemicals and physical method, which are quite toxic and flammable in nature. This study deals with an environmentfriendly biosynthesis process of antibacterial silver nanoparticles using Momordica charantia fruit.Methods: AgNO3 (5 mM) was allowed to react with fruit extract of M. charantia. Biosynthesis of AgNPs was optimized by changing temperature,pH, and solvent. The silver nanoparticles so formed were characterized using ultraviolet-visible (UV-VIS) spectroscopy, Fourier transform infraredspectroscopy (FTIR), dynamic light scattering (DLS), atomic force microscope (AFM), and scanning electron microscopy (SEM).Results: UV-VIS spectra show absorption peak between 420 and 430 nm. The FTIR analysis showed the alcoholic, lactam, and nitro group presentin the plant extract, which were responsible for the reduction in AgNPs. The SEM images showed the size distribution of the nanoparticles and theaverage size was found to be 50-100 nm. By DLS analysis and AFM analysis, average sizes of the silver nanoparticles were of 150 nm. The results ofthese analyses confirmed the formation of silver nanoparticles. Silver nanoparticles were tested against Bacillus cereus and Staphylococcus epidermidisstrains using disc diffusion method and were found to be effective.Conclusion: Silver nanoparticles so synthesized in this study using fruit extract of M. charantia are simple, easy, and effective technique of nanoparticlesproduction.Keywords: Silver nanoparticles, Momordica charantia, Optimization, Antibacterial, Atomic force microscope, Scanning electron microscopy.

Loading AKBA on surface of silver nanoparticles to improve their sedative-hypnotic and anti-inflammatory efficacies

Nanomedicine ◽  
2019 ◽  
Vol 14 (21) ◽  
pp. 2783-2798
Author(s):  
Ajmal Khan ◽  
Ahmed Al-Harrasi ◽  
Najeeb Ur Rehman ◽  
Rizwana Sarwar ◽  
Touqeer Ahmad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Water Solubility ◽  
Boswellic Acid ◽  
Transmission Electron ◽  
Anti Inflammatory ◽  
Compound Materials ◽  
Dose Dependent ◽  
Scanning Electron

Aim: Acetyl-11-keto- β-boswellic acid (AKBA) is a potent anti-inflammatory compound limited by its low water solubility and bioavailability. To load AKBA on silver nanoparticles (AgNPs) to improve bioavailability and water solubility of the compound. Materials & methods: AKBA-AgNPs were chemically synthesized and characterized by UV–Vis spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. AKBA and AKBA-Ag were studied for their sedative-hypnotic and anti-inflammatory efficacies. Results: Pretreatment with AKBA or AKBA-Ag caused significant dose-dependent sedative-hypnotic effects at 5 and 10 mg/kg intraperitoneal. The effects of AKBA-loaded AgNPs caused pronounced changes in mice compared with those of AKBA, and the AKBA-AgNPs demonstrated anti-inflammatory effects that were superior to those of AKBA. Conclusion: The loading of AKBA on nanoparticles improved its pharmacokinetic effects, and capacity for drug delivery.

Characterization of PET-Silver Nanocomposite Filaments

2018 ◽  
Vol 930 ◽  
pp. 224-229
Author(s):  
Marcos Antônio Guerra ◽  
Jeferson Prado Swerts ◽  
Mei Abe Funcia ◽  
Neide Aparecida Mariano ◽  
Maria Gabriela Nogueira Campos
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Addition Method ◽  
X Ray ◽  
Silver Nanocomposite ◽  
Thermal Stability Of ◽  
Scanning Electron

Polyethylene terephthalate (PET) fiber is a very versatile fiber that can be produced with different properties, such as antimicrobial activity. This study aims to synthesize antimicrobial PET filaments incorporated with silver nanoparticles immobilized in silica (NPAg-Si) by bulk additive method. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) characterized the obtained filaments at concentrations (w/w) of 0.008%, 0.016%, 0.032%, 0.047% and 0.063% NPAg-Si, in order to identify the nanoparticles and analyze their dispersion in the polymeric matrix. Moreover, thermogravimetric analysis (TGA) was carry out to confirm the presence and concentration of the silver nanoparticles in the filaments as well as the thermal stability of the nanocomposites. The bulk addition method was efficient to produce PET-Silver filaments with silver nanoparticles homogeneously dispersed in the PET matrix.

scholarly journals Sintesis Nanopartikel Perak Menggunakan Bioreduktor Ekstrak Daun Teh Hijau (Camellia Sinensis) dengan Iradiasi Microwave

2020 ◽  
Vol 21 (1) ◽  
pp. 30
Author(s):  
Dewi Mustika Rahim ◽  
Netti Herawati ◽  
Hasri Hasri
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Tea ◽  
Leaf Extract ◽  
Synthesis Time ◽  
Particle Size Analyzer ◽  
Average Size ◽  
Tea Leaf ◽  
Scanning Electron

ABSTRAK Telah dilakukan penelitian tentang sintesis nanopartikel perak menggunakan bioreduktor ekstrak daun teh hijau (Camellia Sinensis) dengan iradiasi microwave. yang untuk mengetahui pengaruh waktu sintesis dan pengaruh pH stabilizer terhadap sintesis nanopartikel perak ekstrak daun teh hijau dengan iradiasi microwave serta karakterisasinya. Larutan AgNO3 3 mM direduksi menggunakan ekstrak daun teh hijau dan di iradiasi microwave pada variasi waktu sintesis 1-5 menit. Penentuan waktu sintesis optimal menggunakan spektrofotometer UV-Vis diukur setiap 1 menit. Nanopartikel dengan waktu sistesis 4 menit, pH stabilizer menggunakan asam sitrat dan NaOH dengan pH 6-9. Karakterisasi nanopartikel menggunakan instrumen SEM-EDS (Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy) dan PSA (Particle Size Analyzer). Hasil penelitian menunjukkan bahwa waktu sintesis optimal adalah 4 menit. Morfologi nanopatikel perak yang dikarakterisasi menggunakan SEM (Scanning Electron Microscopy) yang dihasilkan cenderung beragregasi. Adanya kecenderungan nanopartikel untuk beragregasi menyebabkan ukuran atau diameter nanopartikel tidak seragam. Ukuran dan distribusi ukuran nanopartikel perak dikarakterisasi menggunakan PSA(Particle Size Analyzer) dihasilkan pada pH 6 antara 31,01 – 402,44 nm dengan rata-rata ukuran sebesar 91 nm, pH 7 antara 35,03 – 740,899 nm dengan rata-rata ukuran sebesar 106,3 nm, pH 8 antara 39,58 – 193,48 nm dengan rata-rata ukuran 71,7, dan pH 9 antara 35,03 – 171,25 nm dengan rata-rata ukuran sebesar 64,4 nm. Disimpulkan bahwa hasil sintesis nanopartikel perak terkecil diperoleh pada pH 9 dan waktu sintesis 4 menit. Kata kunci: Ekstrak Daun Teh Hijau, Nanopartikel Perak, Iradiasi Microwave ABSTRACT Research has been carried out on the synthesis of silver nanoparticles using a bioreductor of green tea leaf extract (Camellia Sinensis) by irradiation microwave.This research aimed to determine the effect of synthesis time and pH stabilizer on the synthesis of silver nanoparticles of green tea leaf extract by microwave irradiation and it’s characterization. The 3 mM AgNO3 solution was reduced using green tea leaf extract and microwave irradiated in a variation of the synthesis time 1-5 minutes. The determining optimum of sythesis time was done by analysis of UV-Vis spectrum for every minutes. Nanoparticles with a synthesis time of 4 minutes, the stabilizer of silver nanoparticles used citric acid and NaOH with a pH of 6-9. Characterization of nanoparticles using SEM-EDS instrument (Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy) and PSA (Particle Size Analyzer). The results showed that the optimal synthesis time was 4 minutes. The morphology of silver nanopaticles characterized using SEM produced tends to aggregate. The tendency of nanoparticles to aggregate causes size or diameter of nanoparticles was random. The size and distribution of size silver nanoparticles characterized using PSA were produced at pH 6 between 31.01 - 402.44 nm with an average size of 91 nm, pH 7 between 35.03 - 740,899 nm with an average size amounting to 106.3 nm, pH 8 between 39.58 - 193.48 nm with an average size of 71.7, and pH 9 between 35.03 - 171.25 nm with an average size of 64.4 nm. It was concluded that the synthesis of the smallest silver nanoparticles was obtained at pH 9 and synthesis time of 4 minutes. Keywords: Green Tea Leaf Extract, Silver Nanoparticles, Microwave Irradiation

scholarly journals Antibacterial ativity of biosynthesized silver nanoparticles against Pseudomonas aeruginosa in vitro

2017 ◽  
Vol 41 (1) ◽  
pp. 60-65
Author(s):  
Ahmad N. A. Salih ◽  
Mohammad J. Eesa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Silver Sulfadiazine ◽  
Diffusion Method ◽  
Olive Leaves ◽  
Scanning Electron

     This study was conducted for the synthesis of silver nanoparticles by using olive leaves aqueous extract and evaluate its antibacterial activity against Pseudomonas aeruginosa in vitro. The synthesis and characterization of silver nanoparticles was confirmed by Ultra Violet Visible – spectrophotometer and Scanning Electron Microscopy. Well diffusion method was used to show the antibacterial action of silver nanoparticles against Pseudomonas aeruginosa in vitro in comparison with standard antibacterial silver sulfadiazine by using different concentrations of each agent ranged from 12.5-200 μg/ml. The results of this study showed it possible to produce silver nanoparticles in eco-friendly and easy process and UV-Visible absorption spectra of the silver nanoparticles revealed maximum absorbance at 420 and 430 nm. The Scanning Electron Microscopy analysis demonstrated the mean of the silver particles diameter was 26 nm. The antibacterial findings of the synthesized silver nanoparticles against Pseudomonas aeruginosa in vitro showed that the silver nanoparticles were more effective than silver sulfadiazine against Pseudomonas aeruginosa. It could be concluded that olive leaves extract can be used effectively in the production of silver nanoparticles and these synthesized nanoparticles had considerable antibacterial activity against Pseudomonas aeruginosa in vitro.                                                        

scholarly journals Silver Nanoparticles: Green Synthesis, Characterization, Blood Compatibility and Protoscolicidal Efficacy against Echinococcus granulosus

2021 ◽  
Vol 41 (03) ◽  
pp. 393-399
Author(s):  
Parwin Jalal Jalil
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Echinococcus Granulosus ◽  
Blood Compatibility ◽  
Ag Nps ◽  
X Ray ◽  
Hydatid Fluid ◽  
Scanning Electron

Spillage of protoscoleces within hydatid fluid during surgery for hydatid cyst is the main reason for its recurrence. Therefore, to inactivate the protoscoleces, various scolicidal substances have been tested. However, novel and more efficient agents are needed owing to several associated complications. This study focused on the effects of green synthetic Silver Nanoparticles (AgNPs) from Zizyphus spina- christi leaves on Echinococcus granulosus protoscoleces. Also, to evaluate the blood compatibility of Ag NPs. The Ag NPs were identified by ultraviolet-visible (UV-Visible) spectrophotometer, X-ray diffraction (XRD), Scanning electron microscopy imaging, and Energy-dispersive X-ray spectroscopy (EDX). Hydatid fluid was aspirated aseptically from cysts of infected sheep liver. The protoscoleces were exposed to Ag NPs at several concentrations. Also, scanning electron microscopy for ultrastructural changes and in vitro erythrocytes lysis was performed. The Ag NPs were spherical; the particles' size reached 50 nm, and presented a surface plasmon peak around 460 nm. The current study's findings indicated the powerful in vitro scolicidal efficacy of the green biosynthesized AgNPs. Several morphological alterations were observed on the protoscoleces by optical and scanning electron microscopy. Lysis of RBCs at different doses of Ag NPs was significantly (P≤0.05) less than the positive control value, thus proposing its biocompatibility. This work suggests that chemicals like polyphenols present in the extract of Z. spina- christi act as reducing and stabilizers agents to create Ag NPs Nevertheless, further investigations are needed to investigate the Ag NPs scolicidial effects in animal models.

scholarly journals Green Synthesis, Characterization, and Evaluation of the Antimicrobial Activity of Camellia sinensis Silver Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Toga Khalid Mohamed ◽  
Marivt Osman Widdatallah ◽  
Maida Musa Ali ◽  
Afraa Mubarak Alhaj ◽  
DhiaEldin AbdElmagied Elhag
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Camellia Sinensis ◽  
Multiple Drug Resistance ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Scanning Electron

An extremely worrying and alarming increase in the level of multiple drug resistance is reported in Sudan, in which bacterial strains are becoming resistant to many commonly available antibiotics. Eventually, it is becoming extremely difficult to treat debilitating infections. In search of promising solutions to this arising crisis, Camellia sinensis silver nanoparticles were synthesized using the green synthesis method. The synthesis of the Camellia sinensis silver nanoparticles is confirmed using analytical methods as ultraviolet-visible spectroscopy, X-ray diffractometer, and scanning electron microscopy. Using the ultraviolet-visible spectroscopy, an absorption band of 412 nm was observed. Furthermore, scanning electron microscopy revealed the presence of silver nanoparticles which fell within the range of 1–100 nm, and X-ray diffractometer analysis showed three intense peaks with a maximum intense peak at 24.3 theta. Nanoparticles distribution between 12 nm and 64 nm was observed with an average diameter of 18.115 nm. It also revealed orthorhombic-shaped nanoparticles. The synthesized nanoparticles showed antimicrobial activity against Staphylococcus aureus with a zone of inhibition of 7 mm, but none was detected against Escherichia coli. The obtained physicochemical properties were correlated with the antibacterial activity of the silver nanoparticles.

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