scholarly journals A utilização da síntese verde para obtenção de nanopartículas de prata a partir de extratos de girassol (Helianthus annuus)

2021 ◽  
Vol 10 (7) ◽  
pp. e41810716795
Author(s):  
Taciany Alves Batista Lemos ◽  
Deuzuita dos Santos Freitas Viana ◽  
Vicente Galber Freitas Viana ◽  
Matheus Henrique da Silva Lemos ◽  
Girlene Soares de Figueirêdo ◽  
...  

A síntese de nanopartículas de prata vem despertando atenção, devido às suas propriedades e aplicações em vários campos da ciência. Essas nanopartículas podem ser produzidas por diferentes métodos utilizando a síntese verde (green synthesis). O que resulta na minimização do custo de produção das nanopartículas. Dessa forma, este trabalho teve como objetivo sintetizar nanopartículas de prata (AgNPs) estabilizada em extratos de girassol (Helianthus annus). A produção da nanopartícula foi realizada em agitação sobre uma chapa magnética aquecida até a configuração total da nanoparticula, ao final foi utilizado o extrato vegetal para a estabilização da mesma. As mesmas foram caracterizadas através do UV-VIS. A analise antimicrobiana das nanoparticulas foi feita em placa de petri com a medição do tamanho do halo inibitório formado. Obteve-se AgNPs a dimensão nos espectros de UV-vis em torno de 20 nanometros. Verificou-se através dos picos de absorção que variou - 414 nm a 422 nm (λmax 422 nm) que o extrato de Helianthus annuus foi capaz de estabilizar com efeito de formação de halo sobre as linhagens de S. aureus (16 mm), E. coli (12 mm) e P. aeruginosa (10 mm), enquanto as AgNPs que não foram estabilizadas com o girassol não apresentaram o halo inibitório. Através desta pesquisa foi possível comprovar que a síntese verde (SV), apesar ser um novo produto nanotecnológico com bases sustentáveis é uma excelente alternativa com uma alta reprodutibilidade e está de acordo com os princípios da química verde, apresentando-se como uma alternativa de baixo custo, eco-amigável e biocompatível na síntese de AgNPs. Além de servir como subsidio para pesquisas posteriores.

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1411
Author(s):  
Mujahid Mehdi ◽  
Huihui Qiu ◽  
Bing Dai ◽  
Raja Fahad Qureshi ◽  
Sadam Hussain ◽  
...  

Fiber based antibacterial materials have gained an enormous attraction for the researchers in these days. In this study, a novel Sericin Encapsulated Silver Nanoclusters (sericin-AgNCs) were synthesized through single pot and green synthesis route. Subsequently these sericin-AgNCs were incorporated into ultrafine electrospun cellulose acetate (CA) fibers for assessing the antibacterial performance. The physicochemical properties of sericin-AgNCs/CA composite fibers were investigated by transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and wide X-ray diffraction (XRD). The antibacterial properties of sericin-AgNCs/CA composite fibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically evaluated. The results showed that sericin-AgNCs incorporated in ultrafine CA fibers have played a vital role for antibacterial activity. An amount of 0.17 mg/mL sericin-AgNCs to CA fibers showed more than 90% results and elevated upto >99.9% with 1.7 mg/mL of sericin-AgNCs against E. coli. The study indicated that sericin-AgNCs/CA composite confirms an enhanced antibacterial efficiency, which could be used as a promising antibacterial product.


2021 ◽  
Vol 10 (6) ◽  
pp. e11710615533
Author(s):  
Taciany Alves Batista Lemos ◽  
Deuzuita dos Santos Freitas Viana ◽  
Vicente Galber Freitas Viana ◽  
Matheus Henrique da Silva Lemos ◽  
Girlene Soares de Figueirêdo
Keyword(s):  

Este estudo objetivou analisar o efeito do extrato de Helianthus Annuus (AgNP@Ha) na síntese de uma nanopartícula de prata e avaliar sua ação antimicrobiana contra bactérias gram-positivo, gram-negativo e fungos. A produção da nanopartícula foi realizada em agitação sobre uma chapa magnética aquecida até a configuração total da nano, ao final foi utilizado o extrato para a estabilização da mesma, o seu tamanho comprovado através do UV-VIS. A análise microbiológica foi feita em placa com medição do tamanho do halo inibitório formado. Obteve-se uma AgNP@Ha com diâmetros de partículas coloidais com variação de 422 - 414 nm (λmax 422 nm) com efeito de formação de halo sobre as linhagens de S. aureus (16 mm), E. coli (12 mm) e P. aeruginosa (10 mm), enquanto as AgNPs que não foram estabilizadas com o girassol não apresentaram o halo inibitório. Através desta pesquisa foi possível comprovar a melhoria da eficiência de ação e de produção ao se utilizar o extrato de girassol para a estabilização. A síntese de nanopartículas de prata utilizando o extrato das sementes de Helianhtus annuus promoveu uma abordagem mais amigável ao meio ambiente, simples, eficiente e com baixo custo para a obtenção de nanopartículas se tornando um excelente produto com potencial antimicrobiano para ser comercializado além de servir como subsídio para pesquisas posteriores.


2020 ◽  
Vol 21 (2) ◽  
pp. 106-113
Author(s):  
D.K. Adeyemi ◽  
A.O. Adeluola ◽  
M.J. Akinbile ◽  
O.O. Johnson ◽  
G.A. Ayoola

Background: Nanotechnology offers an advantage as a green route for synthesis of metal nanoparticles (NPs) with plant extracts as capping agent. Spondias mombin is a fruit-bearing tree and its leaf extracts have been reported to possess anxiolytic, hypoglycaemic, antiepileptic, antipsychotic, sedative, antioxidant, and antimicrobial properties. The objective of the study is to determine the antibacterial potential of a simple non-toxic product of green synthesis of metallic (Ag, Zn and Cu) nanoparticles using the leaf of Spondias mombin aqueous extracts (SMAE) as a reducing and capping agents of the metal ions.Methodology: Nanoparticles were characterized by UV visible spectrophotometeric analysis, Fourier Transform Infra-Red (FT-IR) spectrophotometer and scanning electron microscope (SEM). Antimicrobial activities of synthesized NPs against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were determined by agar well diffusion technique.Results: The synthesized NPs varied in colour from dark brown to green and appears dominantly spherical, occasionally rod or triangular shaped with size ranging from 65-90 nm. UV spectroscopy absorption spectra of Ag, Zn and Cu NPs had absorbance peak at 267, 262 and 765 nm respectively. FT-IR spectrometry of Zn NP, Cu NP, and SMAE gave wave number ranging from 895.71-3320.67, 747.02-3225.45 and 658.25-3674.49 respectively. FT-IR analysis showed that SMAE acted as reducing and stabilizing agent while the NPs exhibited lower energy absorption band when compared to the plant extract. The NPs demonstrated higher antimicrobial activities against S. aureus than Ps. aeruginosa and E. coli. The antimicrobial activity was higher with copper NP than Ag and Zn NPs, and also higher than SMAE.Conclusion: The result from this study presents an indication for an alternative means for development of novel antimicrobial agents for clinical and biotechnological applications.Keywords: synthesis, nanoparticles, FT-IR, UV-visible spectrophotometry, antibacterial activitiesFrench Title: Synthèse verte de nanoparticules d'Ag, de Zn et de Cu à partir d'extrait aqueux de feuilles de Spondias mombin et évaluation de leur activité antibactérienneContexte: La nanotechnologie offre un avantage en tant que voie verte pour la synthèse de nanoparticules métalliques (NP) avec des extraits de plantes comme agent de coiffage. Spondias mombin est un arbre fruitier et ses extraits de feuilles possèdent des propriétés anxiolytiques,  hypoglycémiques, antiépileptiques, antipsychotiques, sédatives,  antioxydantes et antimicrobiennes. L’objectif de l’étude est de déterminer le potentiel antibactérien d’un simple produit non toxique de synthèse verte de nanoparticules métalliques (Ag, Zn et Cu) à l’aide de la feuille d’extraits aqueux de Spondias mombin (SMAE) en tant qu’agent réducteur et coiffant de la ions métalliques.Méthodologie: Les nanoparticules ont été caractérisées par analyse  spectrophotométrique UV visible, spectrophotomètre à transformée de Fourier infrarouge (FT-IR) et microscope électronique à balayage (MEB). Lesactivités antimicrobiennes de NP synthétisées contre Escherichia coli, Staphylococcus aureus et Pseudomonas aeruginosa ont été déterminées par une technique de diffusion sur puits d’agar.Résultats: Les NP synthétisés ont une couleur allant du brun foncé au vert et apparaissent principalement sphériques, parfois en bâtonnets ou en triangles, avec des tailles allant de 65 à 90 nm. Les spectres  d'absorption par spectroscopie UV des NP Ag, Zn et Cu présentaient des pics  d'absorbance à 267, 262 et 765 nm respectivement. La spectrométrie FT-IR de Zn NP, Cu NP et SMAE a donné un nombre d'onde allant de 895,71 à 3320,67, 747,02 à 3225,45 et 658,25 à 3674,49 respectivement. L'analyse FT-IR a montré que le SMAE agissait en tant qu'agent réducteur et  stabilisant, alors que les NP présentaient une bande d'absorption d'énergie inférieure à celle de l'extrait de plante. Les NP ont démontré des activités antimicrobiennes plus élevées contre S. aureus que Ps. aeruginosa et E. coli. L'activité antimicrobienne était plus élevée avec les NP en cuivre que dans les NP Ag et Zn, et également supérieure à celle du SMAE.Conclusion: le résultat de cette étude présente une indication d'un autre moyen de développement de nouveaux agents antimicrobiens pour des applications cliniques et biotechnologiques.Mots-clés: synthèse, nanoparticules, FT-IR, spectrophotométrie UV-visible, activités antibactériennes 


Author(s):  
Tejaswini R ◽  
Dr Anisa Athar

An extract obtained from roasted Coffea arabica bean was used as bio-reductant and mixed with standard AgNO3 (0.1M) solution. The formation of silver nanoparticles(AgNP) was observed by the change in the colour of the solution (coffee extract + AgNO3) from brown to blackish brown. UV-vis spectrophotometry analysis showed maximum adsorption at 240nm. The SEM analysis showed the morphology of the AgNPs as oval and spherical and the sized of the particles between the range of 25nm to 51nm. The crystalline size of the AgNPs was analyzed between the range of 10nm to 30nm employing XRD technique. The antimicrobial activity study of the synthesized silver nanoparticles showed zone of inhibition against the clinically important bacteria namely- E coli, Pseudomonas, Klebsiella, Staphylococcus and Bacillus.


2015 ◽  
Vol 16 (1) ◽  
pp. 171-179
Author(s):  
Yuphada Boonto ◽  
Jirapat Ananpattarachai ◽  
Puangrat Kajitvichyanukul

Silver nanoparticles (AgNPs) have antibacterial properties and are widely used for water disinfection. This technology is commercially applied in point-of-use water treatment as a post-treatment for filtrate water. However, the current process of synthesizing AgNPs has several disadvantages including the use of hazardous chemicals, consumption of a large amount of energy and the formation of hazardous byproducts. Here, we report an alternative and green synthesis using plant extracts. In this work, the plant extracts came from radish (R) and tea (T), and the AgNPs were derived from a microwave irradiation method. The AgNPs synthesized by chemical-based microwave irradiation (Ag-C) were also used as a control material. The novel method produced a smaller size of nanostructures with good dispersion ability and less agglomeration than those from chemical synthesis. The antibacterial properties of AgNPs on Gram-negative bacteria Escherichia coli (E. coli) and Gram-positive bacteria Staphylococcus aureus (S. aureus) were investigated. The results revealed that AgNPs from both green synthesis and chemical-based methods inactivated both types of bacteria. The green-synthesized AgNPs from radish juice provided a higher percentage of inhibition of E. coli than that of S. aureus. The inactivation rates of the AgNPs increased with increasing concentration of AgNPs. As the concentration of the Ag/AgCl-R and Ag-R increased from 150 μg/mL to 300 μg/mL, complete inactivation required a reduced time for the reaction from 300 minutes to only 30 minutes. Finally, the Ag/AgCl-R and Ag-R offered high antibacterial activity while the Ag-T provided the lowest antibacterial activity. This work provides an alternative method for the eco-synthesis of antibacterial nanomaterials for water treatment.


2020 ◽  
Author(s):  
Xinsheng Liu ◽  
Xinlu Li ◽  
Zian Qiao ◽  
Wannan Li ◽  
Bo Gao ◽  
...  

AbstractSunflower (Helianthus annuus L.) contains active ingredients, such as flavonoids, alkaloids and tannins. However, few studies have focused on essential oils from the receptacle of sunflower (SEOs). The chemical composition, antimicrobial and antioxidant activities of SEOs were assessed whether SEOs could be used as nature preservatives and medicines. The extraction rate of SEOs was 0.4% by using hydro-distillation and solvent with petroleum ether, which is much higher than that by only using hydro-distillation (0.2%) in the previous study. A total of 81 volatile constituents of SEOs were identified by gas chromatography-mass spectrometry (GC-MS). The main constituents of SEOs were α-pinene (31.17%), calamenene (5.66%), α-terpineol (4.71%), verbenone (3.15%), kaur-16-ene (2.52%) and terpinolene (1.47%). The antimicrobial activities of SEOs were assessed against three bacteria (E. coli, P. aeruginosa, and S. aureus) and two fungi (S. cerevisiae and Candida albicans). The MIC of SEOs against P. aeruginosa and S. aureus was 0.2 mg/mL. The MIC of SEOs against S. cerevisiae was 3.2 mg/mL. The MIC of SEOs against E. coli and Candida albicans was 6.4 mg/mL. The results showed that SEOs had high antibacterial and antifungal actions. The antioxidant activity was determined with three different analytical assays (DPPH, ABTS and iron reducing ability). The results of antioxidant activities showed that SEOs had high antioxidant activities. The results proved that SEOs could be used as natural preservatives and medicines, due to its excellent antimicrobial and antioxidant activities.


Author(s):  
Khalil Ahmad ◽  
Raeesa Noor ◽  
Muhammad Younus ◽  
Akram Chohan ◽  
Ume Habiba ◽  
...  

Background: Appearance of antibiotic resistance has raised the demand to find alternative therapies and modified drug delivery system of medicinal plants to treat bacterial infections. Objective: The aim of this study is the green synthesis and characterization of silver nanoparticles by using crude extract of Crotalaria burhia and to evaluate their antibacterial potential. Methods: The roots and stems of plant were used to prepare the crude extract. The phytochemical analysis of different compounds in extract was performed. 1mM AgNO3 and different concentrations of plant extract were used for the green synthesis of silver nanoparticles. The particles size and zeta potential were measured by zeta sizer while surface morphology of silver nanoparticles was observed with Scanning Electron Microscope (SEM). The antibacterial activity of silver nanoparticles was performed by 96 well microdilution plate method. Results: The particle size and zeta potential of optimized formulation was 92 nm and -24.8 mV. The SEM analysis showed that silver nanoparticles are irregular and spherical shape. The antibacterial activity showed that MIC value of silver nanoparticles was lower for E. coli than S. aureus. Conclusion: Silver nanoparticles possess potent bactericidal activity against E. coli and moderate activity against S. aureus. It had been concluded that these nanoparticles can be used against multi-drug resistant bacterial infections.


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