scholarly journals Green synthesis of silver nanoparticles (Ag-NPs) from Olea dioica Roxb., leaf extracts and its biological activity

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.,

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.


2018 ◽  
Vol 8 (5-s) ◽  
pp. 301-305
Author(s):  
DR SHOBHA RANI TENKAYALA ◽  
Pagadala R Sougandhi ◽  
Mekala. Reddeppa ◽  
Sapara Sekhar Harini ◽  
R. Gangadhara

In this study, rapid, simple approach was applied for synthesis of silver nanoparticles by using Psidium guajava aqueous leaf extract. The plant extract acts as both reducing agent and capping agent. The green synthesized silver nanoparticles were characterized by using physic-chemical techniques viz, UV-Visible spectroscopy, Fourier Transform Infrared Spectrophotometer [FTIR], Particle size analyser and Scanning electron microscopy. UV-Visible spectrophotometer showed absorbance peak in the range of 419nm.The compounds responsible for silver ions and the functional groups present in plant extract were identified and investigated by FTIR technique. The characterization data reveals that the particles were in crystalline in nature with an average size of 62nm. The silver nanoparticles (Ag NPs) were rapidly synthesized using aqueous extract of guava leaf with AgNO3 solution within 15min at room temperature, without the involvement of any hazardous chemicals. Keywords: Nano particles, green synthesis, Silver,  Psidium guajava and reducing agents.


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.


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.


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.


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