Biosynthesis of Silver Nanoparticles from Eucalyptus corymbia Leaf Extract at Optimized Conditions

2019 ◽  
Vol 25 ◽  
pp. 32-45 ◽  
Author(s):  
Munyao Joshua Sila ◽  
Michira Immaculate Nyambura ◽  
Deborah Atieno Abong’o ◽  
Francis B. Mwaura ◽  
Emmanuel Iwuoha

This study reports the biosynthesis of narrow range diameter silver nanoparticles at optimum conditions usingEucalyptus corymbiaas a reducing and stabilizing agent. Optimal conditions for biosynthesis of silver nanoparticles (AgNPs) were found to be; an extraction temperature of 90°C, pH of 5.7 a Silver Nitrate concentration of 1mM and AgNO3to plant extract ratio of 4:1. UV-Visible spectroscopy monitored the formation of colloidal AgNPs. The UV-Visible spectrum showed a peak around 425 nm corresponding to the Plasmon absorbance of the AgNPs. The size and shape characterization of the AgNPs was done using Transmission Electron Microscopy (TEM) techniques which revealed narrow range diameter (18-20 nm), almost monodispersed AgNPs, spherical in nature and with minimal agglomeration. Energy Dispersive X-ray (EDX) results showed the presence of two peaks at 3.0 and 3.15 keV in the silver region. The Fourier Transform Infrared-Spectra (FTIR) of the plant extract and the AgNPs gave rise to vibrational peaks at 3260 and 1634 wavenumbers which are due to the presence of OH and –C=C-functional groups respectively.

2021 ◽  
Vol 43 (5) ◽  
pp. 513-513
Author(s):  
Abdul Hameed Abdul Hameed ◽  
Komal Saba Komal Saba ◽  
Raheela Taj Raheela Taj ◽  
Andaleeb Azam Andaleeb Azam ◽  
Rohullah and Amna Paracha Rohullah and Amna Paracha

Biocompatibilities of nanoparticles are crucial for biomedical applications. Diverse silver nanoparticles (5 nm, 10 nm, 20 nm, 40 nm and 80 nm) caped with citrate and polyvinylpyrrolidone (PVP) were synthesized and primed their protein coronas. Nanoparticles were characterized with UV-visible spectroscope, Dynamic light scattering (DLS) and Transmission Electron Microscope (TEM). Comparative biocompatibilities were verified and recorded using MTS techniques. Human hepatoma carcinoma HepG2) cell line was used for measuring cytotoxic effect by MTS assays. Deleterious and comparative behaviors of citrate and PVP supported nanoparticles with varied dimensions were investigated and concluded; that citrate caped nanoparticles are comparatively less toxic and independent of size than PVP supported nanoparticles, having increased cytotoxicity with increasing size. The cytotoxic effect of citrate caped and its protein coronas nanoparticles was insignificant, while the boosted concentration of PVP supported nanoparticles enhanced the toxic effect, which endorsed enlarged size and amount of PVP supported nanoparticles. As medicinal precursors, the overwhelming use of PVP nanoparticles should be avoided, and a unique protocol must be designed if its use is crucial and unavoidable.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Naheed Ahmad ◽  
Seema Sharma ◽  
V. N. Singh ◽  
S. F. Shamsi ◽  
Anjum Fatma ◽  
...  

A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag+ ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5–20 nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H+ ions along with NAD which acts as a strong redoxing agent; this seems to be responsible for the formation of AgNPs. Water-soluble antioxidative agents like ascorbic acids further seem to be responsible for the reduction of AgNPs. These AgNPs produced show good antimicrobial activity against common pathogens.


2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.


Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5798
Author(s):  
Amir Reza Sadrolhosseini ◽  
Ganesan Krishnan ◽  
Suhaidi Shafie ◽  
Suraya Abdul Rashid ◽  
Sulaiman Wadi Harun

This study used the carbon dots solution for the laser ablation technique to fabricate silver nanoparticles. The ablation time range was from 5 min to 20 min. Analytical methods, including Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, transmission electron microscopy, and Raman spectroscopy were used to categorize the prepared samples. The UV-visible and z-scan techniques provided optical parameters such as linear and nonlinear refractive indices in the range of 1.56759 to 1.81288 and 7.3769 × 10−10 cm2 W−1 to 9.5269 × 10−10 cm2 W−1 and the nonlinear susceptibility was measured in the range of 5.46 × 10−8 to 6.97 × 10−8 esu. The thermal effusivity of prepared samples, which were measured using the photoacoustic technique, were in the range of 0.0941 W s1/2 cm−2 K−1 to 0.8491 W s1/2 cm−2 K−1. The interaction of the prepared sample with fluoride was investigated using a Raman spectrometer. Consequently, the intensity of the Raman signal decreased with the increasing concentration of fluoride, and the detection limit is about 0.1 ppm.


2013 ◽  
Vol 873 ◽  
pp. 206-210
Author(s):  
Kai Li ◽  
Rao Fu ◽  
Qing Ran Gao ◽  
Ai Wei Tang ◽  
Ying Feng Wang

This paper continues our previous work on preparation of triangular silver nanoparticles. The method proceeds with reaction of silver nitrate with hydrazine hydrate in the presence of polyvinyl pyrrolidone in aqueous solution. Effects of the concentration of PVP on the morphologies of Ag NPs were systematically investigated. The obtained Ag NPs were characterized by transmission electron microscopy and UV-visible spectrophotometer. The results showed that, triangular Ag NPs with edge lengths in the range of 50-200 nm were obtained using PVP as protective agent with lower concentration. As the concentration of PVP increased, spherical Ag NPs with their sizes about 6.2 nm were prepared and triangular Ag NPs were not obtained. The formation mechanism of triangular Ag NPs has been studied. Ostwald ripening is the driving force on the conversion of spherical Ag NPs to triangular Ag NPs in the presence of PVP.


Author(s):  
Shyla Marjorie Haqq ◽  
Amit Chattree

  This review is based on the synthesis of silver nanoparticles (AgNPs) using a green approach which is biofabricated from various medicinal plants. AgNPs were prepared from the various parts of the plants such as the flowers, stems, leaves, and fruits. Various physiochemical characterizations were performed using the ultraviolet (UV)-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, transmission electron microscopy, and energy dispersive spectroscopy. AgNPs were also used to inhibit the growth of bacterial pathogens and were found to be effective against both the Gram-positive and Gram-negative bacteria. For the silver to have antimicrobial properties, it must be present in the ionized form. All the forms of silver-containing compounds with the observed antimicrobial properties are in one way or another source of silver ions. Although the antimicrobial properties of silver have been known, it is thought that the silver atoms bind to the thiol groups in enzymes and subsequently leads to the deactivation of enzymes. For the silver to have antimicrobial properties, it must be present in the ionized form. The study suggested that the action of the AgNPs on the microbial cells resulted into cell lysis and DNA damage. AgNPs have proved their candidature as a potential antibacterial against the multidrug-resistant microbes. The biological agents for synthesizing AgNPs cover compounds produced naturally in microbes and plants. Reaction parameters under which the AgNPs were being synthesized hold prominent impact on their size, shape, and application. Silver nanoparticle synthesis and their application are summarized and critically discussed in this review.


2012 ◽  
Vol 585 ◽  
pp. 144-148
Author(s):  
Poushpi Dwivedi ◽  
S.S. Narvi ◽  
R.P. Tewari

In this nanoregime attempts to bring forth nanoparticles and nanomaterials are myriads, with there interesting and demanding applications in almost every field. Today the field of nanoscience has bloomed with the confluence of nanotechnology with material science, biology, biotechnology and medicine and the need for nanotechnology will only increase as miniaturization becomes extremely important in various arrays of life. Since time immemorial silver nanoparticles have been extensively used for hygienic and healing purposes, and even until most recently, it has indispensible vital role especially in the biomedical arena. Thus in an attempt to generate silver nanoparticles employing green, environmentally benign route, we have designed to converge mythology with technology, with the mystical production of silver nanoparticles, enabled by the blueberry beads of the plant Elaeocarpus granitrus Roxb., the Rudraksha. This non-degradable bead does not disintegrate, but retains the potentiality, even after unlimited production of silver nanoparticles, assisting infinite times. The extremely cost-efficient nanoparticles thus developed in a superiorly efficient manner were characterized through different techniques; like UV/visible spectroscopy, PL spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and nanoparticle size analysis.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Deene Manikprabhu ◽  
K. Lingappa

Traditional synthesis of silver nanoparticles using chemical methods produces toxic substances. In contrast biological synthesis is regarded as a safe and nontoxic process but the major drawback of biological synthesis is, this process is slow. In the present investigation, we developed a rapid and green synthesis of silver nanoparticles employing a pigment produced byStreptomyces coelicolorklmp33 in just 90 s. The silver nanoparticles were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biobased synthesis developed in this method is a safe, rapid, and appropriate way for bulky synthesis of silver nanoparticles.


2016 ◽  
Vol 5 (6) ◽  
Author(s):  
Brajesh Kumar ◽  
Kumari Smita ◽  
Luis Cumbal

AbstractThe present report summarizes an eco-friendly approach for the biosynthesis of silver nanoparticles (AgNPs) using the leaf extract of lavender. Initially, the synthesis of AgNPs was visually observed by the appearance of a wine red color. The optical property, morphology, and structure of as-synthesized AgNPs were characterized by UV-visible spectroscopy, dynamic light scattering, transmission electron microscopy, and X-ray diffraction analyses. All characterization data revealed the formation of crystalline and spherical AgNPs (Ag/Ag


2011 ◽  
Vol 109 ◽  
pp. 174-177 ◽  
Author(s):  
Yu Li Shi ◽  
Qi Zhou ◽  
Li Yun Lv ◽  
Wang Hong

A facile method for the synthesis of silver nanoparticles (NPs) has been developed by using sodium phosphate (Na3PO4) as stabilizing agents and glucose the reducing agent, respectively. The obtained silver NPs have been characterized by X-ray diffraction (XRD), UV-visible spectroscopy (UV-vis) and transmission electron microscopy (TEM). It was found that in the presence of sodium phosphate, silver NPs with different morphologies and sizes were obtained. The formation mechanism of diverse silver NPs was studied preliminarily.


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