scholarly journals Silver nanoparticles from Ziziphus spina-christi (L.) Desf. fruits extract and their antimicrobial activity

2020 ◽  
Vol 49 (4) ◽  
pp. 1127-1134
Author(s):  
Mahmoud Mostafa ◽  
Ahmed Al-Emam ◽  
Mahmoud Sayed ◽  
Saad Alamri ◽  
Huda Alghamdil ◽  
...  

An easy and ecofriendly method to synthesize silver nanoparticles from different stages of ripening fruit extracts of Ziziphus spina-christi is demonstrated. UV-Vis spectroscopy showed a surface resonance peak at 423, 428 and 438 nm corresponding to the formation of AgNPs from ripened, unripened and young fruits, respectively. On the basis of XRD analysis the particle size of three stages of fruit ripening was found to range between 16.5 and 50.76 nm and all had silver metal which was confirmed by EDX. The inhibitory efficacy of AgNPs increased with the ripening progress such as ripened fruit > unripened fruit > young fruit against all tested human pathogenic microbes.  

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Indrawati Patabang ◽  
Syahruddin Kasim ◽  
Paulina Taba

Silver nanoparticles have been synthesized using kluwak leaf extract (Pangium edule Reinw) as bioreductor and antioxidant activity assay. The nanoparticles formed were monitored by observing UV-Vis absorption and characterized by using FTIR, PSA, XRD and SEM instruments. The result of functional group characterization with FTIR show that the functional groups OH, C = O, C-O and CH2 act as Ag+ reducing agent. The size of silver nanoparticles was determined by using Particle Size Analyzer (PSA) and the result show average particle size distribution of 93.2 nm. Morphology of AgNp were observed by Scanning Electron Microscope (SEM) and X-Ray Difraction (XRD) analysis show result of 51,78 nm. The antioxidant activity was shown by in kluwak leaf extract and silver nanoparticles with IC50 values respectively 831,33 ppm dan 1493,09 ppm.


2018 ◽  
Vol 7 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Omid Ahmadi ◽  
Hoda Jafarizadeh-Malmiri ◽  
Naeimeh Jodeiri

Abstract Silver nanoparticles (AgNPs) were synthesized using Aloe vera leaf extract as both reducing and stabilizing agents via microwave irradiation method. The effects of the microwave exposure time and the amount of AgNO3 solution on the mean particle size and concentration of the synthesized AgNPs solution were investigated using response surface methodology. The synthesized AgNPs were characterized by transmission electron microscopy, UV-Vis spectroscopy, and dynamic light scattering. Well-dispersed and spherically fabricated AgNPs with mean particle size (46 nm) and maximum concentration (64 ppm) and zeta potential (+15.5 mV), were obtained at optimal synthesis conditions, using 9 ml of AgNO3 (1 mm) and 0.1 ml of Aloe vera extract during microwave exposure time of 360 s. The antibacterial activity of the synthesized AgNPs was tested using Escherichia coli and Staphylococcus aureus bacteria and the obtained results indicated their significant inhibitory effects against these two Gram-negative and Gram-positive bacteria.


2021 ◽  
Author(s):  
Vanaraj sekar

Abstract A simple and eco-friendly method for the green synthesis of silver nanoparticles (AgNPs) by ultrasound-assisted strategy using Barleria buxifolia leaf extract as a reducing and capping agent was established in this study. The obtained AgNPs were characterized. UV-vis spectrum, Fourier transform infrared spectroscopy (FTIR), scanning and transmission electron microscopy (SEM and TEM), Energy Dispersive X-Ray Analyzer (EDX), X-ray diffraction, dynamic light scattering (DLS) analysis showed that the obtained AgNPs were mono dispersed spheres with uniform size of 80 nm. UV-vis spectroscopy, FTIR, and XRD analysis indicated that the surface of the obtained AgNPs was covered with organic molecules in plant extracts. The results of ABTS assays showed that high antioxidant activity was seen in the obtained AgNPs. Green synthesized AgNPs showed potent antibacterial and anti-biofilm activity against tested pathogens. Cytotoxicity assay showed that the obtained AgNPs were significantly cytotoxic to cancer cell line (MCF-7). In addition, the AgNPs synthesized in this paper can also photo catalytically degrade methylene blue dye under visible light. The potent bioactivity exhibited by the green synthesized silver nanoparticles leads towards the multiple use as antioxidant, antibacterial, anti-biofilm, cytotoxic as well as photo catalytic agent.


Author(s):  
Kashan Khan ◽  
Mohd Aamir Qureshi ◽  
Ameer Azam ◽  
Moinuddin ◽  
Javed Musarrat ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Margarita I. Skiba ◽  
Victoria I. Vorobyova ◽  
Alexander Pivovarov ◽  
Natalya P. Makarshenko

The process of obtaining aqueous solutions of silver nanoparticles with the use of a low-temperature nonequilibrium contact plasma and stabilizing agent—polysaccharide (sodium alginate)—has been examined. The synthesized Ag NPs were characterized by using UV-Vis spectroscopy, dynamic light scattering (DLS), scanning electron microscope (SEM), and XRD analysis. The effect of concentration of Ag+, sodium alginate, duration of processing by plasma discharge, and pH of liquid on the production of silver nanoparticles has been studied. The results demonstrated that synthesis provides the formation of silver nanoparticles for investigated concentrations of Ag+ (0.3-3.0 mmol/l) and 5.0 g/l Na-Alg (pH=7–10) within 1–5 minutes. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles have a face-centered cubic crystal structure. Zeta potential of plasma-chemically obtained colloidal solutions at various concentrations of Ag+ ions and stabilizing agent varies from −32.8 to −39.3 mV, indicating the moderate stability of synthesized nanoparticles.


2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.


2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Vladimir Popov ◽  
Ivaylo Hinkov ◽  
Svetlomir Diankov ◽  
Maria Karsheva ◽  
Yordan Handzhiyski

AbstractThe antimicrobial activity of nanoparticles (NPs) depends of the surface area in contact with microorganisms. The large surface area of the nanoparticles enhances their interaction with the microbes. In this work, a green, simple, rapid, and efficient ultrasound-assisted reduction method for silver nanoparticles (AgNP) synthesis is presented. For the synthesis, an aqueous solution of silver nitrate, ethanol, and ammonia was used. The adopted method can be easily implemented for any kind of scientific or industrial application due to its cost-effective nature. The effect of sonication time on the nanoparticle formation was investigated. Silver nanoparticles were analyzed through transmission electron microscopy and UV-vis spectroscopy. Antimicrobial additives can be incorporated in mass in different matrixes (polymeric or cellulosic), which is a convenient methodology to achieve antimicrobial activity. In this work, silver nanoparticles were incorporated in cellulose using an ultrasonic bath technique. The most important aspect of cellulose containing silver nanoparticles prepared by this method is its high antimicrobial efficiency. The microbiological study was carried out by a standard agar technique. The analysis showed that cellulose with incorporated silver nanoparticles exhibited strong antimicrobial activity against


2010 ◽  
Vol 644 ◽  
pp. 85-90 ◽  
Author(s):  
Rebeca G. Melendez ◽  
Karla J. Moreno ◽  
Ivana Moggio ◽  
Eduardo Arias ◽  
Arturo Ponce ◽  
...  

In this paper, we studied the influence of the silver nanoparticles size on the electrical conductivity of PEDOT:PSS in Ag(PEDOT:PSS) films. The silver nanoparticles were synthesized in presence of PEDOT:PSS by varying the molar ratio between AgNO3 and the reducing agent (NaBH4). Both the particle size determined by TEM and the plasmon band obtained by UV-Vis spectroscopy were found to be strongly dependent on the reducing agent concentration. The electrical conductivity increases inversely with the concentration of reducing agent from 5.24 x 10-4 up to 1.63 S/cm; three orders of magnitude higher than pristine PEDOT:PSS.


2021 ◽  
Vol 12 (2) ◽  
pp. 2361-2372

In recent years, developing nanoparticles with green processes is gaining huge attention due to its cost-effectiveness, simplicity and non–toxic precursors. The present study utilized the potential of egg white for the synthesis of stable silver nanoparticles (EW-AgNPs). In order to characterize the EW-AgNPs, various techniques have been employed. UV-vis spectroscopy (300-700nm) was used to study the λmax, which highlighted the peak at 422nm. Further, the stability of synthesized EW-AgNPs was studied using Zeta potential, the value of -16.4 mV was obtained, indicating the stability of developed EW-AgNPs in the solution. Transmission electron microscopy was used specifically to visualize the shape and size of synthesized EW-AgNPs, the images showed spherical to the diverse shape of EW-AgNPs. In the first phase, the EW-AgNPs were studied for dye degradation along with NaBH4. The enhanced dye degradation of blue dye was obtained with EW-AgNPs+NaBH4, showing 90- 100% degradation from 100- 25 mgL-1 dye solution, respectively. Further, in the second phase, antimicrobial activity (Zone of Inhibition) of EW-AgNPs was analyzed against Escherichia coli and Staphylococcus aureus. A higher ZOI was obtained for E.coli (16mm) than S. aureus (12.4mm). The present study proved egg white's ability to develop stable silver nanoparticles, which was further found to be effective for blue dye degradation and antimicrobial activity.


2021 ◽  
pp. 174-179
Author(s):  
Sinthia Ganesan ◽  
Palanichamy Mehalingam ◽  
Govindan Sadasivam Selvam

Ginger spent is the byproduct of spice industries that remove the essential oils of ginger (Zingiber officinale) for food industry and medicinal purposes. Ginger is a well known spice used often for seasoning in Indian cuisine. The de-oiled ginger has no specific use mostly goes to waste. Hence, we utilized this industrial waste product in the efficient synthesis of silver nanoparticles with the aid of UV irradiation from a solution of 1mM silver nitrate and spent extract in the ratio 9:1. Immediate colour change from pale yellow to dark brown was noted indicating the rapid synthesis of silver nanoparticles. These nanoparticles were centrifuged, dried and well characterized. UV Vis Spectroscopy, XRD analysis, Zeta potential and SEM analysis was carried out. It was commendable that the size of the nanoparticles fell well within the upper limit of 100nm. Agar well diffusion method was used to screen the antimicrobial activity of the well characterized silver nanoparticles. They were tested against seven pathogenic strains of three gram negative bacteria (Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) three gram positive bacteria(Bacillus subtilis, Staphylococcus aureus and Streptococcus faecalis) and a fungus (Candida  albicans). It was seen that the zone of inhibition(ZOI) in well plate method  increased on increasing the concentration of silver nanoparticles. Further studies could lead to the application of these silver nanoparticles in medicine.


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