scholarly journals Green Synthesis of Stable Spherical Monodisperse Silver Nanoparticles Using a Cell-Free Extract of Trichoderma reesei

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 481
Author(s):  
Orlin Gemishev ◽  
Marinela Panayotova ◽  
Gospodinka Gicheva ◽  
Neli Mintcheva

In the current study, a green method for the preparation of silver nanoparticles (AgNPs) is presented as an alternative to conventional chemical and physical approaches. A biomass of Trichoderma reesei (T. reesei) fungus was used as a green and renewable source of reductase enzymes and metabolites, which are capable of transforming Ag+ ions into AgNPs with a small size (mainly 2–6 nm) and narrow size distribution (2–25 nm). Moreover, extracellular biosynthesis was carried out with a cell-free water extract (CFE) of T. reesei, which allows for facile monitoring of the bioreduction process using UV–Vis spectroscopy and investigation of the effect of experimental conditions on the transformation of Ag+ ions into AgNPs, as well as the simple isolation of as-prepared AgNPs for the study of their size, morphology and antibacterial properties. In continuation to our previous results about the influence of media on T. reesei cultivation, the amount of biomass used for CFE preparation and the concentration of Ag+ ion solution, herein, we present the impact of temperature (4, 20, 30 and 40 °C), agitation and time duration on the biosynthesis of AgNPs and their properties. A high stability of AgNPs in aqueous colloids was observed and attributed to the capping effect of the biomolecules as shown by the zeta potential (−49.0/−51.4 mV) and confirmed by the hydrodynamic size of 190.8/116.8 nm of AgNPs.

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4041
Author(s):  
Adriana Cecilia Csakvari ◽  
Cristian Moisa ◽  
Dana G. Radu ◽  
Leonard M. Olariu ◽  
Andreea I. Lupitu ◽  
...  

Cannabis sativa L. (hemp) is a plant used in the textile industry and green building material industry, as well as for the phytoremediation of soil, medical treatments, and supplementary food products. The synergistic effect of terpenes, flavonoids, and cannabinoids in hemp extracts may mediate the biogenic synthesis of metal nanoparticles. In this study, the chemical composition of aqueous leaf extracts of three varieties of Romanian hemp (two monoecious, and one dioecious) have been determined by Fourier-Transformed Infrared spectroscopy (FT-IR), high-performance liquid chromatography, and mass spectrometry (UHPLC-DAD-MS). Then, their capability to mediate the green synthesis of silver nanoparticles (AgNPs) and their pottential antibacterial applications were evaluated. The average antioxidant capacity of the extracts had 18.4 ± 3.9% inhibition determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 78.2 ± 4.1% determined by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS™) assays. The total polyphenolic content of the extracts was 1642 ± 32 mg gallic acid equivalent (GAE) L−1. After this, these extracts were reacted with an aqueous solution of AgNO3 resulting in AgNPs, which were characterized by UV−VIS spectroscopy, FT-IR, scanning electron microscopy (SEM-EDX), and dynamic light scattering (DLS). The results demonstrated obtaining spherical, stable AgNPs with a diameter of less than 69 nm and an absorbance peak at 435 nm. The mixture of extracts and AgNPs showed a superior antioxidant capacity of 2.3 ± 0.4% inhibition determined by the DPPH• assay, 88.5 ± 0.9% inhibition as determined by the ABTS•+ assay, and a good antibacterial activity against several human pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas fluorescens, and Staphylococcus aureus.


Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Mahsa Eshghi ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Mohammad Najian ◽  
Hoda Jafarizadeh-Malmiri ◽  
...  

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.


2013 ◽  
Vol 57 (10) ◽  
pp. 4945-4955 ◽  
Author(s):  
Divya Prakash Gnanadhas ◽  
Midhun Ben Thomas ◽  
Rony Thomas ◽  
Ashok M. Raichur ◽  
Dipshikha Chakravortty

ABSTRACTThe emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapyin vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activityin vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand thein vivorelevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activitiesin vivoagainstSalmonellainfection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3241
Author(s):  
Manal N. Abdel Azeem ◽  
Safwat Hassaballa ◽  
Osama M. Ahmed ◽  
Khaled N. M. Elsayed ◽  
Mohamed Shaban

More suitable wastewater treatment schemes need to be developed to get rid of harmful dyes and pigments before they are discharged, primarily from apparel and textile factories, into water bodies. Silver nanoparticles (Ag-NPs) are very effective, reductive nanocatalysts that can degrade many organic dyes. In this study, Ag-NPs are stabilized and capped with bioactive compounds such as Galaxaura elongata, Turbinaria ornata, and Enteromorpha flexuosa from marine macroalgae extracts to produce Ag[GE], Ag[TE], and Ag[EE] NPs. The reduction of Ag ions and the production of Ag[GE], Ag[TE], and Ag[EE] NPs have been substantiated by UV–Vis spectroscopy, SEM, EDX, and XRD tests. The NPs are sphere and crystalline shaped in nature with dimensions ranging from 20 to 25 nm. The biosynthesized Ag[GE], Ag[TE], Ag[EE] NPs were applied to photodegrade hazardous pigments such as methylene blue, Congo red, safranine O, and crystal violet under sunlight irradiation. In addition to the stability analysis, various experimental parameters, including dye concentration, exposure period, photocatalyst dose, and temperature, were optimized to achieve 100% photodegradation of the dyes. Moreover, the thermodynamic and kinetic parameters were calculated and the impact of scavengers on the photocatalytic mechanism was also investigated.


2020 ◽  
Vol 12 (4) ◽  
pp. 1484 ◽  
Author(s):  
M. Asimuddin ◽  
Mohammed Rafi Shaik ◽  
Neeshat Fathima ◽  
M. Shaistha Afreen ◽  
Syed Farooq Adil ◽  
...  

Due to their low cost and environmentally friendly nature, plant extracts based methods have gained significant popularity among researchers for the synthesis of metallic nanoparticles. Herein, green synthesis of silver nanoparticles was performed using the aqueous solution of Ziziphus mauritiana leaves extract (ZM-LE) as a bio-reducing agent. The as-obtained silver nanoparticles were characterized by using UV-Vis spectroscopy, XRD (X-ray diffraction), TEM (transmission electron microscopy), and FT-IR (Fourier-transform infrared spectroscopy). In addition, the effects of the concentrations of the leaves extract, silver nitrate, and the temperature on the preparation of nanoparticles were also investigated. In order to determine the nature of secondary metabolites present in leaves extract, a preliminary investigation of phytoconstituents was carried out using different methods including Folin-Ciocalteu and AlCl3 methods. The results have indicated the presence of a considerable amount of phenolic and flavonoid contents in the leaves extract, which are believed to be responsible for the reduction of silver ions and stabilization of resulting nanoparticles. Indeed, the FT-IR spectrum of silver nanoparticles also confirmed the presence of residual phytomolecules of leaves extract as stabilizing ligands on the surface of nanoparticles. The antibacterial properties of as-obtained silver nanoparticles were tested against various bacterial strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis. The nanoparticles strongly inhibited the growth of S. aureus with a minimum inhibitory concentration (MIC) of 2.5 μg/ml and moderately inhibited the growth of E. coli with a MIC of 5 μg/ml.


2015 ◽  
Vol 60 (4) ◽  
pp. 2631-2636
Author(s):  
M. Wojnicki ◽  
I. Mania ◽  
M. Marzec ◽  
M. Gajewska ◽  
K. Mech

Present work describes the influence of silver nanoparticles precursor form as well as the impact of graphene oxide initial concentration on deposition of the silver nanoparticles onto graphene oxide. Borane dimethylamine complex (DMAB) was used as the reducing agent. It was observed that application of silver ammonia complexes as the silver nanoparticles precursor as well as alkaline solution effect in higher quantity of deposited AgNPs in comparison to deposition process with the use of silver(I) nitrate in acidic solution.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Francisco Javier Alvarez-Cirerol ◽  
Marco Antonio López-Torres ◽  
Ericka Rodríguez-León ◽  
César Rodríguez-Beas ◽  
Aaron Martínez-Higuera ◽  
...  

Early Mortality Syndrome (EMS) or Acute Hepatopancreatic Necrosis Syndrome (AHPNS) is a disease produced by gram-negative bacteria Vibrio parahaemolyticus (V. parahaemolyticus), which has caused declines in worldwide production of a white shrimp Litopenaeus vannamei (L. vannamei). In this work, we propose the implementation of silver nanoparticles (AgNPs) synthesized with Rumex hymenosepalus (Rh) extract as an alternative on V. parahaemolyticus control. AgNPs were characterized by UV-Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). AgNP mean sizes by DLS were 80.82±1.16 nm and sizes between 2 and 10 nm by TEM, with a zeta potential of −47.72±1.05 mV. This study evaluated AgNPs and Rh antimicrobial capacity on V. parahaemolyticus at different concentrations; the minimum inhibitory concentration (MIC) found was 25 μg/mL for AgNPs and 220 μg/mL for Rh. Additionally, were carried out time-kill curves and reactive oxygen species (ROS) generation for 1 and 4 MIC. Both concentrations (MIC) were tested for toxicity on Artemia nauplii from Artemia franciscana (A. franciscana), because nauplii were used as biocarriers for AgNPs and Rh extract on L. vannamei. Once the shrimp were treated, they were challenged with Vibrio infection and it was found that those who were treated with both agents showed greater survival than the control. V. parahaemolyticus and postlarval samples were taken from the bioassay and fixed and prepared for TEM and SEM in order to search NPs in internal structure of bacteria and the hepatopancreatic area of shrimps; AgNPs were detected in both cases. AgNPs and Rh extract show antibacterial properties on the infected shrimp with V. parahaemolyticus. The action mechanisms are interaction with the bacterial membrane and ROS generation; these effects are produced by both agents.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2112 ◽  
Author(s):  
Mudassir Iqbal ◽  
Hadia Zafar ◽  
Azhar Mahmood ◽  
Muhammad Bilal Khan Niazi ◽  
Muhammad Waqar Aslam

This research endeavor aims to develop polyvinyl alcohol (PVA) based films capable of blends with silver nanoparticles (Ag–NPs) for improved antibacterial properties and good mechanical strength to widen its scope in the field of wound dressing and bandages. This study reports synthesis of propylamine-substituted PVA (PA–PVA), Ag–NPs via chemical and green methods (starch capping) and their blended films in various proportions. Employment of starch-capped Ag–NPs as nanofillers into PVA films has substantially improved the above-mentioned properties in the ensuing nanocomposites. Synthesis of PA–PVA, starch-capped Ag–NPs and blended films were well corroborated with UV/Vis spectroscopy, FTIR, NMR, XRD and SEM analysis. Synthesized Ag–NPs were of particle shape and have an average size 20 nm and 40 nm via green and chemical synthesis, respectively. The successful blending of Ag–NPs was yielded up to five weight per weight into PA–PVA film as beyond this self-agglomeration of Ag–NPs was observed. Antibacterial assay has shown good antimicrobial activities by five weight per weight Ag–NPs(G)-encapsulated into PA–PVA blended film, i.e., 13 mm zone inhibition against Escherichia coli and 11 mm zone inhibition against Staphylococcus aureus. Physical strength was measured in the terms of young’s modulus via tensile stress–strain curves of blended films. The five weight per weight Ag–NPs(G)/PA–PVA blend film showed maximum tensile strength 168.2 MPa while three weight per weight Ag–NPs(G)/PVA blend film showed highest values for ultimate strain 297.0%. Ag–NPs embedment into PA–PVA was resulted in strong and ductile film blend than pristine PA–PVA film due to an increase in hydrogen bonding. These good results of five weight per weight Ag–NPs(G)/PA–PVA product make it a potent candidate for wound dressing application in physically active body areas.


2011 ◽  
Vol 66 (9) ◽  
pp. 905-916 ◽  
Author(s):  
Boris Mahltig ◽  
Marianne Reibold ◽  
Emanuel Gutmann ◽  
Torsten Textor ◽  
Jochen Gutmann ◽  
...  

This study describes the development of a preparation technique for silver nanoparticles useable as antimicrobial material which is especially useful for textile treatment to realize antimicrobial fabrics. The silver particles need to be prepared by reduction of AgNO3 under moderate conditions and with a moderate and non-toxic reductive agent. Comparative investigations were carried out with silver particles prepared by a solvothermal process or with NaBH4 as reductive agent. Particularly, suitable silver solutions are obtained by stabilizing the silver particles with polyvinylpyrollidone PVP of high molecular weight (Mw ~ 360000 gmol−1) and the use of the non-toxic reductive agents ascorbic acid and fructose. Under these conditions the diameters of the silver particles are in the range of 10 to 30 nm as determined by HR-TEM. The formation of elemental silver has been verified by transmission electron microscopy (TEM), X-ray diffraction (XRD) and optical spectroscopy. The properties of silver particle-containing liquids were investigated by using UV/Vis spectroscopy and dynamic light scattering. Further information on particle size and size distribution was gained through SEM investigations. The prepared solutions of silver nanoparticles can be applied easily onto textiles as liquid coating agents. All prepared textile samples exhibited a high antimicrobial activity against Escherichia coli. However, only few solutions containing silver particles of smaller size exhibit high antimicrobial activity also against other types of bacteria such as Staphylococcus aureus and Streptococcus pneumoniae. Because of this high antimicrobial potential gained with silver solutions prepared in a simple process without usage of toxic components, the developed materials offer a broad range of potential applications.


Author(s):  
M. Nowak ◽  
A. Tolińska ◽  
L. Marciniak ◽  
M. Skrobańska ◽  
B. Tylkowski ◽  
...  

AbstractThis study aimed to assess the characteristics, including morphology, physicochemical properties, and antibacterial properties, of silver nanocolloids obtained by D-glucose reduction. Silver nanoparticles were synthesized in accordance with the principles of green chemistry using D-glucose as a reductor. The obtained nanostructures were characterized by UV–vis spectroscopy, transmission electron microscopy, and dynamic light scattering. Stability tests performed after 1 month of storage revealed that the colloids prepared with and without polyvinylpyrrolidone as a stabilizer had the same properties. Distribution of the nanoparticles was tested using inductively coupled plasma mass spectrometry by doping the silver colloids into a natural soap mass. The antibacterial activity of the soap containing silver nanoparticles was tested on dirty hands. The antibacterial activity test demonstrated that the novel green soap materials improved with D-glucose-reduced silver nanoparticles possessed better antibacterial properties than a pure soap, and thus, they could be recommended for quotidian use by dermatological patients.


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