scholarly journals Green Synthesis of Silver Nanoparticles using Polyalthia longifolia Stem Bark Extract and its Catalytic Reduction of 4-Nitrophenol

2019 ◽  
Vol 31 (11) ◽  
pp. 2439-2442
Author(s):  
Karuppiah Muthu ◽  
B. Akilandaeaswari ◽  
S. Mangala Nagasundari

In this present study, green synthesis of silver nanoparticles (AgNPs) was synthesized from silver nitrate using the reducing agents of Polyalthia longifolia bark extract and applied the catalyst in the reduction/degradation of environmental polluted organic compound in the presence of NaBH4. Initially, the colourless reaction mixture was slowly changed to yellowish brown, UV-visible spectroscopy of surface plasmon resonance centre at 447 nm confirmed the formation of AgNPs. High resolution transmission electron microscopy (HRTEM) clearly identified the spherical shapes nanoparticles with diameters sizes 5-25 nm. This AgNPs has excellent catalyst in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as compared to the reducing agent of NaBH4 (chemical) and plant extract (natural).

Author(s):  
A S Ningrum ◽  
A P Pridyantari ◽  
W Handayani ◽  
K Secario ◽  
D Djuhana ◽  
...  

Author(s):  
A ANTONY LAWRENCE ◽  
J THOMAS JOSEPH PRAKASH

Objective: The present study was to synthesize nanoparticles using Manilkara hexandra stem bark extract its characterization and evaluating it by an antimicrobial and antioxidant assay. Methods: Manilkara hexandra stem bark silver nanoparticles (MHSB-AgNPs) was done by mixing silver nitrate (1 mmol) and aqueous stem bark extract and it was analyzed by UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), Zeta potential, Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDAX), Thermogravimetry/Differential Thermal Analysis (TG/DTA) and Differential scanning calorimetry (DSC). The antibacterial assay was done by a well diffusion method and also examined for antifungal assay was done by disk diffusion method and antioxidant potential Diphenyl-1-picryl hydrazyl (DPPH method) Results: Manilkara hexandra stem bark silver nanoparticles (MHSB-AgNPs) is characterized by various techniques such as UV-visible absorption spectrum ranges from 430 nm to 440 nm indicate silver nanoparticles. The Fourier Transform Infrared Spectroscopy consists of biomolecules acts as capping agent to form silver nanoparticles. Field Emission Scanning Electron Microscopy shows particle size ranges from 15 nm to 50 nm. Energy Dispersive Spectroscopy shows the presence of Silver. X-ray Diffraction corresponds to face-centered lattice planes (111), (200), (220) and (311). Dynamic Light Scattering show the range of 68 nm and Zeta potential show the negative value of-17 nm which has high stability. Silver nanoparticles is also examined by Thermogravimetry/Differential Thermal Analysis (TG/DTA) and Differential scanning calorimetry (DSC) this project the thermal stability of the nanoparticles. The aqueous stem bark is also examined by UV-visible absorption spectrum, Fourier Transform Infrared Spectroscopy (FTIR), and Gas Chromatography-Mass Spectrometry (GCMS). In GCMS 20 compounds were identified. Silver nanoparticles show high zone of inhibition in antimicrobial assays and act as a good antioxidant agent. Conclusion: It is eco-friendly, non-toxic, and it’s easy to synthesis and it shows good result in an antimicrobial and antioxidant assay can be applied in a pharmaceutical application.


Author(s):  
Ojeyemi M. Olabemiwo ◽  
Sunday A. Akintelu ◽  
Aisha A. Waheed ◽  
Dasola S. Okunlola ◽  
Darasimi R. Akinwale ◽  
...  

2021 ◽  
Author(s):  
Ojeyemi M. Olabemiwo ◽  
Sunday Akintelu ◽  
Aisha A. Waheed ◽  
Dasola S. Okunlola ◽  
Darasimi R. Akinwale ◽  
...  

Author(s):  
Md. Abdullah Al Masud ◽  
Hamid Shaikh ◽  
Md. Shamsul Alam ◽  
M. Minnatul Karim ◽  
M. Abdul Momin ◽  
...  

Abstract Background The green synthesis strategy of metallic nanoparticles (NPs) has become popular due to being environmentally friendly. Stable silver nanoparticles (AgNPs) have been synthesized by natural products such as starch, soy protein, various extract of leaves, barks, and roots functioning both as reducing and stabilizing agents. Likewise, silk sericin (SS) is a globular protein discarded in the silk factory might be used for NP synthesis. In this research, we focus on the green synthesis and stabilization of AgNPs by SS as well as assessment of their antibacterial activities against some drug-resistant pathogen. Results SS was extracted from Bombyx mori silkworm cocoons in an aqueous medium. 17 w/w% of dry sericin powder with respect to the cocoon’s weight was obtained by freeze-drying. Furthermore, AgNPs conjugated to sericin, i.e., SS-capped silver nanoparticles (SS-AgNPs) were synthesized by easy, cost-effective, and environment-friendly methods. The synthesized SS-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction measurement. It has been found from the absorbance of UV-visible spectroscopy that a higher percent of SS-AgNPs was obtained at a higher concentration of silver nitrate solution. FTIR-ATR spectra showed that the carboxylate groups obtained from silk sericin act as a reducing agent for the synthesis of silver nanoparticles, while NH2+ and COO− act as a stabilizer of AgNPs. The X-ray diffractogram of SS-AgNPs was quite different from AgNO3 and sericin due to a change in the crystal structure. The diameter of AgNPs was around 20–70 nm observed using TEM. The synthesized SS-AgNPs exhibited strong antibacterial activity against multidrug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 20μg/mL. Conclusions This study encourages the use of Bombyx mori for the ecofriendly synthesis of SS-AgNPs to control multidrug-resistant microorganisms.


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.


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.


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