scholarly journals Green synthesis and stabilization of earthworm-like gold nanostructure and quasi-spherical shape using Caesalpinia sappan Linn. extract

2018 ◽  
Vol 7 (5) ◽  
pp. 424-432 ◽  
Author(s):  
Widsanusan Chartarrayawadee ◽  
Chee O. Too ◽  
Sukunya Ross ◽  
Gareth M. Ross ◽  
Kanlaya Jumpatong ◽  
...  

AbstractGreen synthesis of nanoparticles (NPs) has received much attention due to biocompatibility and being facile and eco-friendly.Caesalpinia sappanLinn. (CS) is a plant found in Southeast Asia and is commonly known as sappan wood. In this research, we are the first to successfully use CS extract as reducing and stabilizing agents for the green synthesis of gold NPs (AuNPs). Colloidal solutions of AuNPs after reduction show natural red-wine and dark purple color depending on the size of AuNPs, without the interference of the orange/reddish-orange color from the CS extract. The concentration of CS was investigated for the formation and stabilization of AuNPs in colloidal solution (i.e. morphology, size and zeta potential). It was found that the optimized concentration of the reducing agent for the green synthesis of AuNPs was in the range of 0.004–0.04 wt% of CS. As the concentration of CS was increased, the sizes of AuNPs decreased due to the adsorption and stabilizing effect of CS. Transmission electron microscopy (TEM) analysis showed differences in size and shape of the NPs with earthworm and quasi-spherical characteristics. The zeta potential of AuNPs synthesized in the presence of CS was approximately in the range of −10 mV to −20 mV, indicating the stability of AuNPs synthesized by CS.

Author(s):  
Mohib Shah ◽  
Natasha Anwar ◽  
Samreen Saleem ◽  
Iqbal Munir ◽  
Niaz Ali Shah ◽  
...  

Background. Nanotechnology is promising field for generating new applications. A green synthesis of nanoparticles through biological methods using plant extract have a reliable and ecofriendly approach to improve our global environment. Methods. Silver nanoparticles (AgNPs) were synthesized using aqueous extract of Anagalis arvensis L and silver nitrate and were physicochemically characterized. Results. The stability of AgNPs toward acidity, alkalinity, salinity and temperature showed that they remained stable at room temperature for more than two months. The SEM and TEM analysis of the AgNPs showed that they have a uniform spherical shape with an average size in the range of 40–78 nm. Further 1-Dibhenyl-2-Picrylhydrazl radical in Anagalis arvensis L.mediated AgNPs showed a maximum activity of 98% at concentration of 200μg/mL. Hydrogen peroxide scavenging assay in Anagalis arvensis L. mediated AgNPs showed a maximum activity of 85% at concentration of 200μg/mL. Reducing power of Anagalis arvensis L.Ag NPs exhibited a higher activity of 330 μg/mL at concentration of 200 μg/mL. These NPs have cytotoxic effects against brine shrimp (Artemia salina) nauplii with a value of 53% LD 178.04μg/mL. Conclusion. The AgNPs synthesized using Anagalis arvensis L. extract demonstrate a broad range of applications.


Author(s):  
Yoki Yulizar ◽  
Harits Atika Ariyanta ◽  
Lingga Abduracman

Gold nanoparticles (AuNPs) have been successfully prepared by green synthesis method using aqueous extract of garlic with the Latin name of Allium sativum L. (ASL) as a reducing and stabilizing agents. Identification of active compounds in aqueous ASL extract was conducted by phytochemical analysis and Fourier transform infrared (FTIR) spectroscopy, while the synthesized AuNPs were characterized using UV-Vis spectrophotometer and transmission electron microscopy-selected area electron diffraction (TEM-SAED). The AuNPs formation was optimized at aqueous ASL extract concentration of 0.05%, HAuCl4 concentration of 2.0×10-4 M, and pH of 3.6. The optimized AuNPs was characterized   using TEM, and has a spherical shape with particle size of 15±3 nm. The particles were also stable up until one month. The synthesized AuNPs has been studied its interaction with melamine, and showed the optimum pH of interaction at 3.6. Copyright © 2017 BCREC GROUP. All rights reservedReceived: 13rd November 2016; Revised: 3rd January 2017; Accepted: 10th February 2017How to Cite: Yulizar, Y., Ariyanta, H.A., Abdurrachman, L. (2017). Green Synthesis of Gold Nanoparticles using Aqueous Garlic (Allium sativum L.) Extract, and Its Interaction Study with Melamine. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 212-218 (doi:10.9767/bcrec.12.2.770.212-218)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.770.212-218 


Author(s):  
V. Jhansi Lakshmi ◽  
K. P. Kannan

Objective: The present study was aimed to investigate gold nanoparticles synthesized by fungal isolate Neosartorya udagawae and determination of their stability in biofluids to probe their aptness in drug delivery applications.Methods: In this procedure, gold nanoparticles were prepared by biosynthesis using seven days old culture of Neosartorya udagawae and aqueous chloroauric acid. After the complete reaction, the fungal biomass was subjected to UV-Vis, XRD, FT-IR Spectrum analysis, TEM, Zeta potential, SEM and EDX analysis.Results: Intra/extracellular synthesis of gold nanoparticles was confirmed by a sharp peak at 526 nm in UV spectroscopy. SEM, TEM analysis demonstrates the spherical shape of AuNPs with an average diameter of 50 nm and XRD confirm the crystalline gold nanoparticles. FTIR analysis reveals the presence of the protein shell around the gold nanoparticles. The zeta potential value of AuNPs was-36mV which confirmed the stability of nanoparticles dispersion. Gold nanoparticles have shown high stability in biofluids of Bovine Serum Albumin and Phosphate Buffer Saline at pH-5, pH-7and pH-9 which mimic the human colonic biological environment.Conclusion: The fungal synthesis of AuNPs has been experimentally demonstrated and their stability in BSA, 10% NaCl and PBS at pH-7. This might be a promising option for drug delivery applications in carcinogenic colon disorders in human beings. 


Author(s):  
S. Shinozaki ◽  
J. W. Sprys

In reaction sintered SiC (∽ 5um average grain size), about 15% of the grains were found to have long-period structures, which were identifiable by transmission electron microscopy (TEM). In order to investigate the stability of the long-period polytypes at high temperature, crystal structures as well as microstructural changes in the long-period polytypes were analyzed as a function of time in isothermal annealing.Each polytype was analyzed by two methods: (1) Electron diffraction, and (2) Electron micrograph analysis. Fig. 1 shows microdensitometer traces of ED patterns (continuous curves) and calculated intensities (vertical lines) along 10.l row for 6H and 84R (Ramsdell notation). Intensity distributions were calculated based on the Zhdanov notation of (33) for 6H and [ (33)3 (32)2 ]3 for 84R. Because of the dynamical effect in electron diffraction, the observed intensities do not exactly coincide with those intensities obtained by structure factor calculations. Fig. 2 shows the high resolution TEM micrographs, where the striped patterns correspond to direct resolution of the structural lattice periodicities of 6H and 84R structures and the spacings shown in the figures are as expected for those structures.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1085
Author(s):  
Rocío Chong-Cerda ◽  
Laura Levin ◽  
Rocío Castro-Ríos ◽  
Carlos Eduardo Hernández-Luna ◽  
Azucena González-Horta ◽  
...  

One primary drawback of enzyme catalysis at industrial scale is the short-term service life of the enzymes, they lose their activity due to oxidation or other processes which results in less stability and a shorter lifetime thereby rendering them less efficient. An effective way to increase the stability of the enzymes is to attach them to nanoparticles. In this work, the polymer Eudragit® L 100-55 sensitive to pH was used to prepare laccase polymeric nanoparticles by the double-emulsion solvent evaporation approach. The size and morphology of the nanoparticles obtained were evaluated—as well as the encapsulation efficiency and zeta potential. pH effect on activity and stability was compared between free and immobilized laccase. Their stability was also determined in a sequential assay involving acidic pHs up to alkaline ones. The nanoparticles had a spherical shape with a mean size of 147 nm, zeta potential of −22.7 mV at pH 7.0 and load efficiency of 87%. The optimum pH of both free and immobilized laccases was 3.0, being the nanoparticles more stable at acidic pHs. Thus, this would be the first report of obtaining laccase nanoparticles with potential application in animal feed due to the stability conferred to enzymatic activity at pHs similar to those present in the gastrointestinal tract of rabbits, which would allow their potential use in animal feed.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh ◽  
S. M. El-Rafie ◽  
E. S. Abdel-Halim ◽  
M. H. El-Rafie

Green synthesis aims to minimize the use of unsafe reactants and maximize the efficiency of synthesis process. These could be achieved by using environmentally compassionate polymers and nontoxic chemicals. Hydroxyethyl cellulose (HEC), an ecofriendly polymer, was used as both reducing and stabilizing agents in the synthesis of stable silver nanoparticles, while silver nitrate was used as a precursor and water as a solvent. The formation of silver nanoparticles was assessed by monitoring UV-vis spectra of the silver colloidal solution. The size of the nanoparticles was measured using transmission electron microscope (TEM). Reaction kinetics was followed by measuring the absorbance of silver colloidal solution at different time intervals. Optimum reaction conditions revealed that the highest absorbance was obtained using HEC : AgNO3 of 1.5 : 0.17 (g/100 cm3) at 70°C for 120 min at pH 12. The Ag0 nanoparticles colloidal solution so obtained (1000 ppm) were found stable in aqueous solution over a period of six months at room temperature (°C). The sizes of these nanoparticles were found in the range of 11–60 nm after six months of storing. FTIR spectra confirmed the interaction of both the aldehyde and OH groups in the synthesis and stabilization of silver nanoparticles.


2021 ◽  
Vol 12 (7) ◽  
pp. 25-31
Author(s):  
Pooja . ◽  
Pankaj Kumar Sharma ◽  
Viswanath Agrahari

Background: The aim of this study is to develop a liquid self-nano emulsifying drug delivery system for alverine (liquid-SNEDDS).Excipients in the alverine SNEDDS include Ethyl oleate as the oil phase, Tween 80 as a surfactant, and PEG600, Propylene glycol as a cosurfactant.The prepared eleven formulations of alverine SNEDDS were performed for emulsification time, percentage transmittance, particle size, drug release, in vitro dissolution and stability studies.The optimised alverine liquid SNEDDS formulation (D1) was studied for drug-excipient compatibility using infrared spectroscopy, as well as particle size, zeta potential, transmission electron microscopy, and stability. Alverine SNEDDS have a spherical shape with uniform particle distribution, according to their morphology. D1's optimised formulation's drug release percentage (96.6). The stability data revealed no discernible changes in drug content, emulsifying properties, drug release, or appearance. As a result, a potential SNEDDS formulation of alverine with improved solubility, dissolution rate, and bioavailability was developed.


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1485 ◽  
Author(s):  
Marta Rubio-Camacho ◽  
Yolanda Alacid ◽  
Ricardo Mallavia ◽  
María José Martínez-Tomé ◽  
C. Reyes Mateo

Multifunctional nanoparticles have been attracting growing attention in recent years because of their capability to integrate materials with different features in one entity, which leads them to be considered as the next generation of nanomedicine. In this work, we have taken advantage of the interesting properties of conjugated polyelectrolytes to develop multicolor fluorescent nanoparticles with integrating imaging and therapeutic functionalities. With this end, thermosensitive liposomes were coated with three recently synthesized polyfluorenes: copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(phenylene)) bromide (HTMA-PFP), copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-4,7-(2- (phenyl)benzo(d) (1,2,3) triazole)) bromide (HTMA-PFBT) and copoly-((9,9-bis(6′-N,N,N- trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(naphtho(2,3c)-1,2,5-thiadiazole)) bromide (HTMA-PFNT), in order to obtain blue, green and red fluorescent drug carriers, respectively. The stability, size and morphology of the nanoparticles, as well as their thermotropic behavior and photophysical properties, have been characterized by Dynamic Light Scattering (DLS), Zeta Potential, transmission electron microscope (TEM) analysis and fluorescence spectroscopy. In addition, the suitability of the nanostructures to carry and release their contents when triggered by hyperthermia has been explored by using carboxyfluorescein as a hydrophilic drug model. Finally, preliminary experiments with mammalian cells demonstrate the capability of the nanoparticles to mark and visualize cells with different colors, evidencing their potential use for imaging and therapeutic applications.


nano Online ◽  
2018 ◽  
Author(s):  
Widsanusan Chartarrayawadee ◽  
Chee O. Too ◽  
Sukunya Ross ◽  
Gareth M. Ross ◽  
Kanlaya Jumpatong ◽  
...  

2014 ◽  
Vol 917 ◽  
pp. 3-9
Author(s):  
Muhammad Ayoub ◽  
Ahmad Zuhairi Abdullah

Mesoporous material SBA-15 was synthesized using P123 and TEMOS as the templates. Lithium in the form of LiOH was loaded over a previously prepared SBA-15. The basic strength of the prepared samples of SBA-15 was found to increase but the mesoporous structure was severely destroyed. The mesoporous structure of the prepared SBA-15 was retained after coating it with 30 wt. % magnesium prior to LiOH loading. The stability of mesoporous structure was strongly influenced by the extent of magnesium coating. It was also noted that this structure was also affected by LiOH loading and significantly destroyed structure when magnesium coating value exceeded 20 %. These samples were thoroughly characterized for their surface area, pore volume, pore size, basic strength, SAXRD patterns and transmission electron microscopic (TEM) analysis.


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