scholarly journals Silver nanoparticles synthesized using leaf extract of Azadirachta indica exhibit enhanced antimicrobial efficacy than the chemically synthesized nanoparticles: A comparative study

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110121
Author(s):  
Kashan Khan ◽  
Saleem Javed

A wide variety of methods have synthesized silver nanoparticles (Ag-NPs) in the recent past; however, biological methods have attracted much attention over the traditional chemical synthesis method due to being non-hazardous and eco-friendly. Here, a detailed and systemic study was performed to compare two different synthesis routes for Ag-NPs, that is, the chemical and the biological; their possible outcomes have also been described. Ag-NPs were synthesized chemically (cAg-NPs) using a chemical reductant and biologically (bAg-NPs) by using aqueous leaf extract of Azadirachta indica (neem). The synthesized nanoparticles were characterized using UV-visible spectrophotometry, FT-IR, EDX, and TEM. The average particle sizes (APS) of cAg-NPs were found to be 8 and 13 nm and of bAg-NPs to be 19 and 43 nm under different AgNO3 concentrations. The antimicrobial tests of differently sized NPs were performed against Escherichia coli (Gram −ve) and S taphylococcus aureus (Gram +ve). The results revealed that bAg-NPs of APS 43 nm were highly antimicrobial against both the tested bacterial stains followed by cAg-NPs of 8 nm. We found the effect of cAg-NPs to be size-dependent, whereas bAg-NPs showed a more significant antimicrobial effect than cAg-NPs.

2017 ◽  
Vol 57 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Abdul A. Buhroo ◽  
Gousul Nisa ◽  
Syed Asrafuzzaman ◽  
Ram Prasad ◽  
Razia Rasheed ◽  
...  

AbstractThe present exploration is focused on the bio-fabrication of silver nanoparticles (Ag NPs) usingTrichodesma indicumaqueous leaf extract as a reducing agent. The synthesized Ag NPs were productively characterized by UV-vis spectroscopy, XRD, and TEM studies. The photosynthesis of Ag NPs was done at room temperature for 24 h and at 60°C. The green synthesis of spherical-shaped Ag NPs bio-fabricated fromT. indicumwith a face centred cubic structure showed average particle sizes of 20–50 nm, which is inconsistent with the particle size calculated by the XRD Scherer equation and TEM analysis. We further explored the larvicidal efficacy of biosynthesized Ag NPs with leaf extracts ofT. indicumagainstMythimna separata. The results showed that Ag NPs (20–50 nm) ofT. indicumpossess good larvicidal activity againstM. separatawith an LC50of 500 ppm. Thus, we can advocate that Ag NPs of 20–50 nm size extracted fromT. indicummay be considered in the pest management programme ofM. separatain future.


2020 ◽  
Vol 9 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Samaira Yasmin ◽  
Shazia Nouren ◽  
Haq Nawaz Bhatti ◽  
Dure Najaf Iqbal ◽  
Shan Iftikhar ◽  
...  

AbstractCurrently, the green route for synthesis of silver nanoparticles (Ag NPs) using plants leaf extract is an emerging research area in nanotechnology. The present study was explored for synthesis, characterization and catalytic application of Ag NPs using Diospyros lotus fresh leaf extracts. Factors affecting the synthesis were optimized and optimum conditions were pH of 8.6, silver nitrate (AgNO3) concentration of 1.5 mM and 10 mL leaf extract. Formation of Ag NPs was observed by change in color of reaction mixture from pale yellow to reddish brown. The synthesized Ag NPs were characterized using UV-Vis spectrophotometer, EDX, XRD and SEM analyses. UV-Vis spectrophotometer showed maximum absorbance peak in the range of 407 nm at different time intervals indicating formation of Ag NPs. SEM and XRD analysis confirmed face centered cubic structure and crystalline nature of biologically synthesized Ag NPs with average particle size of 27 nm. The purity of synthesized Ag NPs was revealed by EDX. Finally, photo catalytic activity (PCA) of Ag NPs was studied and 72.91% decolorization of industrial waste water was obtained at 54 h. Some important parameters like pH, turbidity, conductance; TSS, TDS, sulphide, sulphates, etc. were also monitored before and after treatment with Ag NPs.


Author(s):  
K. Kalpana K. Anandaraj

Nanoparticles have attracted scientific responsiveness due to their fascinating properties, commercial and biotechnological applications advantageous over their bulk counterparts This is principally due to their small size and, subsequently, the remarkable surface area of NPs. Presently, advances in the synthesis, stabilization and production of AgNPs have adopted a new generation of commercial products and intensified scientific investigation within the nanotechnology field. In the present study, Ag NPs are synthesized in the presence of the aqueous leaf extract of Coriandrum sativum. The biosynthesized nanoparticles were characterized by UV– Vis spectra, FT-IR, XRD, and SEM analysis. Further, the antibacterial activity of the biosynthesized nanoparticles was tested against the selected bacterial isolates. Ag NPs exhibited maximum antagonistic activity towards Pseudomonas aeruginosa.


2016 ◽  
Vol 9 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Shakeel Ahmed ◽  
Saifullah ◽  
Mudasir Ahmad ◽  
Babu Lal Swami ◽  
Saiqa Ikram

Biomedicine ◽  
2020 ◽  
Vol 39 (4) ◽  
pp. 544-549
Author(s):  
G. K. Pratap ◽  
Manjula Shantaram

Introduction and Aim: The silver nanoparticles have attained a special place in the area of nanotechnology because of their different biological applications. Fabrication of nanoparticles using green synthesis is  done because of its wide applications in different fields such as biomedical, medicine, agriculture and food engineering. This study is to develop an easy and eco-friendly method for the synthesis of Ag-NPs using leaf extracts of the medicinal plant. Materials and Methods: The medicinal plants are rich sources of various medicinal properties. Olea dioica Roxb., leaf extract was used to investigate the effects of Ag-NPs having antibacterial activity and antioxidant capacity.  The plant leaf extract contains flavonoids, alkaloids, saponins, and phenolic compounds which acts as reducing and stabilizing agents. The green synthesized silver nanoparticles were characterized by various techniques like UV- visible spectrophotometer, FTIR spectroscopy, and SEM analysis. Results: The synthesis of sliver nanoparticles from plant source, and analysis of nano particles by UV-Vis spectra, SEM and FTIR. The biological evaluations of Ag-NPs indicated an excellent inhibitory efficacy, antioxidant and antimicrobial activity for their future applications in medicine. Conclusion: The synthesized silver nanoparticles exhibited potent antioxidant and antimicrobial activities against Gram-positive and Gram-negative bacteria. The silver (Ag-NPs) nanoparticles synthesized by the pot green synthesis method proves its potential use in various medical applications. Keywords: Silver nanoparticles; Medicinal plants; Ag-NPs; Olea dioica Roxb.,


2018 ◽  
Vol 4 (5) ◽  
pp. 527-532
Author(s):  
Diksha B. Lade ◽  
Dayanand P. Gogle ◽  
Bipin D. Lade

The main purpose of the experiment is to use green synthesis method for silver nanoparticles (SNP) fabrication using phytochemical and functional groups inherent in aqueous leaf extract of Ocimum sanctum and Ocimum basilicum for formulation of polyethylene glycol (PEG)/ Glycerine film. The SNP synthesis reaction is performed under sun condition and change in colour from light brown to dark brown was the initial indication, observed for nanoparticles synthesis. The 95 mL of 0.001 M AgNO3 is mixed with 5 mL of leaf extract and reaction performed under Sun light at alkaline pH 8 was found efficient to produced stable NP. The synthesized SNP are mixed with (10%, 50%, 100%, 150%, 200% and 250%), polyethylene glycol (PEG):glycerine (G) in 1:1 ratio to form a film. The UV-spectroscopic analysis confirms absorption at 420-430 nm for synthesized SNP. The FTIR characterization determines alkynes (terminal), 1�, 2� amines, amides, nitriles, alkynes, alkyl halides functional group from O. sanctum (OS) leaf extract and aldehydes, alkynes (terminal), alkyne, alkene, from O. basilicum (OB) leaf extract responsible for reducing and capping silver nitrate to form nanoparticles. The SEM analysis verify that the O. sanctum based nanoparticles are spherical in shape although O. basilicum based nanoparticles have bright contrast coral reef like morphology. The average zeta potential of silver nanoparticles was found to be 27.74 mV and 23.50 mV that are embedded in Ocimum sanctum-SNP/PEG and Ocimum basilicum-SNP/PEG films. Also, the average diameters of SNP in Ocimum sanctum-SNP/PEG and in Ocimum basilicum-SNP/PEG was found to be 463.2 nm and 43.0 nm. These Sun light mediated SNP shows antimicrobial activity against E. coli and S. aureous pathogens.


2021 ◽  
Vol 9 (3) ◽  
pp. 220-226
Author(s):  
Bishow Regmi ◽  
Tirtha Raj Binadi ◽  
Sarb Narayan Jha ◽  
Rajib Kumar Chaudhary ◽  
Bhoj Raj Poudel ◽  
...  

Silver nanoparticles (AgNPs) have been synthesized by green synthesis using Azadirachta indica leaf extract as both reducing and stabilizing agent. Synthesis of colloidal AgNPs was monitored by UV- visible spectroscopy. The UV- visible spectrum showed a peak at 455 nm corresponding to the plasmon absorbance of the silver nanoparticles. Crystallite structure of silver nanoparticles was studied using X-ray diffraction (XRD) analysis which revealed the face-centered cubic structure (FCC) with average particle size of 8.9 nm, calculated using Debye-Scherrer’s equation. Transmission electron microscopy (TEM) image revealed the agglomeration of small grain with particle size ranging from 2 to 14 nm. FCC crystalline nature was also evident from selected area electron diffraction (SAED) analysis. High purity of as-synthesized AgNPs was analyzed using energy dispersive X-ray (EDX) spectroscopy. Band gap energy was calculated to be 2.7 eV from UV- Visible spectra. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was stabilized by AgNPs which reveals its antioxidant efficacy. Well diffusion method showed 7 mm to 12 mm zone of inhibition (ZOI) against Gram-positive and Gram-negative bacteria, respectively confirming the antibacterial potential of AgNPs. Int. J. Appl. Sci. Biotechnol. Vol 9(3): 220-226.


Author(s):  
M. Linga Rao ◽  
Bhumi G ◽  
Savithramma N

Silver nanoparticles (SNPs) exhibit tremendous applications in medicine as antimicrobial agent.  The use of different parts of plants for the synthesis of nanoparticles is considered as a green technology as it does not involve any harmful chemicals.  In the present study, we report a rapid biosynthesis of silver nanoparticles from aqueous leaf extract of medicinal plant Allamanda cathartica.  The active phytochemicals present in the plant were responsible for the quick reduction of silver ion to metallic silver nanoparticles. The reduced silver nanoparticles were characterized by using UV-Vis spectrophotometry, Scanning Electron Microscope (SEM), Energy Dispersive Analysis of X-ray (EDAX) and Atomic Force Microscopy (AFM).  The spherical shaped silver nanoparticles were observed and it was found to 19-40 nm range of size.  These phytosynthesized SNPs were tested for their antimicrobial activity and it analyzed by measuring the inhibitory zone. A. cathartica aqueous leaf extract of SNPs showed highest toxicity to Pseudomonas followed by Klebsiella, Bacillus and E. coli and lowest toxicity towards Proteus. In fungal species, highest inhibition zone was noted against Rhizopus followed by Curvularia, Aspergillus flavus and Aspergillus niger and minimum inhibition zone was observed against Fusarium species.  These results suggest a promising potential of Indian plant-based green chemistry for production of SNPs for biomedical and nanotechnology applications.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1007
Author(s):  
Azam Ali ◽  
Mariyam Sattar ◽  
Fiaz Hussain ◽  
Muhammad Humble Khalid Tareen ◽  
Jiri Militky ◽  
...  

The versatile one-pot green synthesis of a highly concentrated and stable colloidal dispersion of silver nanoparticles (Ag NPs) was carried out using the self-assembled tannic acid without using any other hazardous chemicals. Tannic acid (Plant-based polyphenol) was used as a reducing and stabilizing agent for silver nitrate in a mild alkaline condition. The synthesized Ag NPs were characterized for their concentration, capping, size distribution, and shape. The experimental results confirmed the successful synthesis of nearly spherical and highly concentrated (2281 ppm) Ag NPs, capped with poly-tannic acid (Ag NPs-PTA). The average particle size of Ag NPs-PTA was found to be 9.90 ± 1.60 nm. The colloidal dispersion of synthesized nanoparticles was observed to be stable for more than 15 months in the ambient environment (25 °C, 65% relative humidity). The synthesized AgNPs-PTA showed an effective antimicrobial activity against Staphylococcus Aureus (ZOI 3.0 mM) and Escherichia coli (ZOI 3.5 mM). Ag NPs-PTA also exhibited enhanced catalytic properties. It reduces 4-nitrophenol into 4-aminophenol in the presence of NaBH4 with a normalized rate constant (Knor = K/m) of 615.04 mL·s−1·mg−1. For comparison, bare Ag NPs show catalytic activity with a normalized rate constant of 139.78 mL·s−1·mg−1. Furthermore, AgNPs-PTA were stable for more than 15 months under ambient conditions. The ultra-high catalytic and good antimicrobial properties can be attributed to the fine size and good aqueous stability of Ag NPs-PTA. The unique core-shell structure and ease of synthesis render the synthesized nanoparticles superior to others, with potential for large-scale applications, especially in the field of catalysis and medical.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Akshay Rajeev Geetha ◽  
Elizabeth George ◽  
Akshay Srinivasan ◽  
Jameel Shaik

Production of silver nanoparticles from the leaf extracts ofPimenta dioicais reported for the first time in this paper. Three different sets of leaves were utilized for the synthesis of nanoparticles—fresh, hot-air oven dried, and sun-dried. These nanoparticles were characterized using UV-Vis spectroscopy and AFM. The results were diverse in that different sizes were seen for different leaf conditions. Nanoparticles synthesized using sun-dried leaves (produced using a particular ratio (1 : 0.5) of the leaf extract sample and silver nitrate (1 mM), resp.) possessed the smallest sizes. We believe that further optimization of the current green-synthesis method would help in the production of monodispersed silver nanoparticles having great potential in treating several diseases.


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