scholarly journals Synthesis of Gold Nanoparticles and Association of DNA-Gold Nanoparticles

2016 ◽  
Vol 11 (2) ◽  
pp. 77
Author(s):  
Weon Bae Ko ◽  
Young Min Lee ◽  
Sung Kyu Hong ◽  
Sung Sook Choi ◽  
Sang Jin Lee
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Gel Electrophoresis ◽  
Bos Taurus ◽  
Ionic Surfactant ◽  
Polysorbate 80 ◽  
Specific Primer ◽  
Binding Ability ◽  
Transmission Electron ◽  
Vis Spectroscopy

<p>This study examined the synthesis of gold nanoparticles using a non-ionic surfactant, polysorbate 80, and KAuCl<sub>4 </sub>in water. The gold nanoparticles, which were well dispersed in water, were analyzed by UV-vis spectroscopy and transmission electron microscopy (TEM). In addition, the SRY(sex-determining region Y) gene of the Bos taurus specific primer was designed, and this primer solution was mixed with the aqueous gold nanoparticles solution. The binding ability of DNA and gold nanoparticles was identified by polyacryllamide gel electrophoresis. The products of DNA linked with gold nanoparticles were also characterized by UV-vis spectroscopy and TEM.</p>

scholarly journals Effects of Different Surfactant Charges on the Formation of Gold Nanoparticles by the LASiS Method

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2937
Author(s):  
Muhammad Zulfajri ◽  
Wei-Jie Huang ◽  
Genin-Gary Huang ◽  
Hui-Fen Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Laser System ◽  
Synthesis Process ◽  
Au Nps ◽  
Laser Fluences ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
532 Nm

The laser ablation synthesis in solution (LASiS) method has been widely utilized due to its significant prospects in laser microprocessing of nanomaterials. In this study, the LASiS method with the addition of different surfactant charges (cationic CTAB, nonionic TX-100, and anionic SDS) was used to produce Au NPs. An Nd:YAG laser system at 532 nm excitation with some synthetic parameters, including different laser fluences, ablation times, and surfactant concentrations was performed. The obtained Au NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, and zeta potential analyzer. The Au NPs exhibited the maximum absorption peak at around 520 nm for all samples. The color of Au NPs was changed from red to reddish by increasing the laser fluence. The surfactant charges also played different roles in the Au NPs’ growth during the synthesis process. The average sizes of Au NPs were found to be 8.5 nm, 5.5 nm, and 15.5 nm with the medium containing CTAB, TX-100, and SDS, respectively. Besides, the different surfactant charges induced different performances to protect Au NPs from agglomeration. Overall, the SDS and CTAB surfactants exhibited higher stability of the Au NPs compared to the Au NPs with TX-100 surfactant.

scholarly journals Biosynthesized gold nanoparticles-doped hydroxyapatite as antibacterial and antioxidant nanocomposite

2021 ◽  
Author(s):  
Is Fatimah ◽  
Putwi Widya Citradewi ◽  
Amri Yahya ◽  
Bambang Nugroho ◽  
Habibi Hidayat ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antioxidant Activity ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging

Abstract The composite of green synthesized gold nanoparticles (Au NPs)-doped hydroxyapatite (HA) has been prepared. The gold nanoparticles were produced via bioreduction of HAuCl4 with Clitoria ternatea flower extract, and utilized in the synthesis of hydroxyapatite using Ca(OH)2 and ammonium diphosphate as precursor. The aim of this research is to study the structural analysis of the composite and antibacterial activity test toward Eschericia coli, Staphylococcus aureus, Klebsiela pneumoniae, and Streptococcus pyogenes. In addition, the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The monitoring of gold nanoparticles formation was conducted by UV–vis spectroscopy and particle size analyses, meanwhile the synthesized composite was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that homogeneously dispersed gold nanoparticles in HA structure was obtained with the particle size ranging at 5-80 nm. The nanocomposite demonstrated antibacterial activity against tested bacteria. The nanocomposite expressed an antioxidant activity as shown by the DPPH scavenging activity of 66 and 58% at the concentration of 100 μg/mL and 50 μg/mL, respectively.

Synthesis of Chitosan-Stabilized Gold Nanorod Using Tripolyphosphate

2013 ◽  
Vol 652-654 ◽  
pp. 250-253
Author(s):  
Hua Nan Guan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Chemical Synthesis ◽  
Gold Nanorods ◽  
Gold Nanorod ◽  
Gold Salt ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Seed Mediated

An improvement in the previously reported seed-mediated chemical synthesis of gold nanorods (GNRs) is reported. Gold nanoparticles were prepared by reducing gold salt with a polysaccharide, chitosan, in the presence of tripolyphosphate (TPP). The obtained gold nanoparticles were characterized with UV-vis spectroscopy and transmission electron microscopy. The study shows that TPP plays an important role in the formation of GNRs.

scholarly journals SYNTHESIS AND CATALYTIC ACTIVITY OF BRANCHED GOLD NANOPARTICLES IN AQUEOUS MEDIUM

2018 ◽  
Vol 55 (5B) ◽  
pp. 227
Author(s):  
Phan Ha Nu Diem
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Kinetic Data ◽  
Gold Nanostructures ◽  
Simple Method ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Experimental Parameters

In this article, a simple method for the preparation of multi–branched gold nanoparticles from an aqueous solution of silver seeds, cetyl-trimethylammonium bromide (CTAB), HAuCl4, and Pluronic F–127 was described. It was found that morphologies and sizes of gold nanostructures (AuNPs) depended strongly on such experimental parameters as concentrations of Pluronic F–127 and Au3+. The products were characterized by transmission electron microscopy (TEM). Interestingly, the multi – branched AuNPs were found to serve as an effective catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4. Kinetic data have been obtained from monitoring the concentrations of 4-NP and BH4‒ by UV‒vis spectroscopy.

BIOSYNTHESIS AND CHARACTERIZATION OF GOLD NANOPARTICLES USING THE ALGA Kappaphycus alvarezii

2010 ◽  
Vol 09 (05) ◽  
pp. 511-516 ◽  
Author(s):  
P. RAJASULOCHANA ◽  
R. DHAMOTHARAN ◽  
P. MURUGAKOOTHAN ◽  
S. MURUGESAN ◽  
P. KRISHNAMOORTHY
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Kappaphycus Alvarezii ◽  
Nanoparticle Synthesis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Gold Nanoparticle Synthesis

As a part of our ongoing investigation into the use of algae for gold nanoparticle synthesis, we screened the marine alga Kappaphycus alvarezii, to investigate its efficiency to reduce gold ions as well as the formation of gold nanoparticles. In the present work, we report the reaction condition of the alga K. alvarezii with aqueous gold ions for gold nanoparticle synthesis within the biomass extracellularly. The formation of gold nanoparticles was characterized by UV–Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) method. Moreover, we have found that the reaction of gold ions with the K. alvarezii biomass under stationary conditions results in the rapid extracellular formation of gold nanoparticles of spherical morphology. The gold nanoparticles are not toxic to the cells that continued to grow after the biosynthesis of the gold nanoparticles.

scholarly journals Green synthesis of gold nanoparticles using cinnamon bark extract, characterization, and fluorescence activity in Au/eosin Y assemblies

2020 ◽  
Vol 22 (10) ◽  
Author(s):  
Omar S. ElMitwalli ◽  
Omar A. Barakat ◽  
Rabbani M. Daoud ◽  
Sultan Akhtar ◽  
Fryad Z. Henari
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Spherical Shape ◽  
Bark Extract ◽  
Eosin Y ◽  
Cinnamon Bark ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Average Size ◽  
Fluorescence Peak

Abstract This study reports the synthesis of gold nanoparticles (AuNPs) using an unconventional, eco-friendly method that utilizes cinnamon bark extract as a reducing agent and stabilizer. The synthesized AuNPs were characterized using UV–Vis spectroscopy and transmission electron microscopy (TEM). UV–Vis spectrum shows the surface plasmon resonance (SPR) peak around 535 nm. TEM shows the spherical shape of AuNPs and the particle size distribution at around 35 nm. The ability of the synthesized AuNPs as a quencher of eosin Y dye was monitored using a fluorometer. It was found that in the presence of AuNPs, the fluorescence peak of eosin is quenched. The fluorescence of the mixture of eosin and AuNPs is enhanced in the presence of bovine serum albumin (BSA) protein. TEM shows that the average size of the AuNPs is reduced from 35 to 5 nm with the addition of eosin, and the size of AuNPs then increased to 26 nm upon adding BSA to the mixture of ANPs and eosin. These fluorescence fluctuations may be used for trace identification and biosensing.

scholarly journals Synthesis of Gold Nanoparticles Stabilized in Dextran Solution by Gamma Co-60 Ray Irradiation and Preparation of Gold Nanoparticles/Dextran Powder

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Phan Ha Nu Diem ◽  
Doan Thi Thu Thao ◽  
Dang Van Phu ◽  
Nguyen Ngoc Duy ◽  
Hoang Thi Dong Quy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Spherical Shape ◽  
Powder Form ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Influence Of Ph ◽  
Dextran Solution

Gold nanoparticles (AuNPs) in spherical shape with diameter of 6–35 nm stabilized by dextran were synthesized by γ-irradiation method. The AuNPs were characterized by UV-Vis spectroscopy and transmission electron microscopy. The influence of pH, Au3+ concentration, and dextran concentration on the size of AuNPs was investigated. Results indicated that the smallest AuNPs size (6 nm) and the largest AuNPs size (35 nm) were obtained for pH of 1 mM Au3+/1% dextran solution of 5.5 and 7.5, respectively. The smaller Au3+ concentration favored smaller size and conversely the smaller dextran concentration favored bigger size of AuNPs. AuNPs powders were prepared by spay drying, coagulation, and centrifugation and their sizes were also evaluated. The purity of prepared AuNPs powders was also examined by energy dispersive X-ray (EDX) analysis. Thus, the as-prepared AuNPs stabilized by biocompatible dextran in solution and/or in powder form can be potentially applied in biomedicine and pharmaceutics.

scholarly journals Synthesis of Gold Nanoparticles Conjugated with Protein A: Towards the Application in Biosensors for Virus Detection

2011 ◽  
Vol 21 (4) ◽  
pp. 333
Author(s):  
Tran Quang Huy ◽  
Mai Anh Tuan
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Influenza A Virus ◽  
Influenza A ◽  
Protein A ◽  
Virus Detection ◽  
Sodium Ascorbate ◽  
Virus Particles ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, a facile and effective technique is described to prepare a complex of gold nanoparticles (GNPs)/protein A (PrA) for biosensors in virus detection. GNPs were synthesized by the reduction of tetrachloroauric (III) acid trihydrate using sodium ascorbate, and then coated with PrA via ultracentrifugation. The complex of GNPs/PrA was characterized using UV-vis spectroscopy and transmission electron microscopy. The immunogold labeling method of scanning electron microscopy was also used to verify the capacity for the detection and binding of GNPs/PrA to H$_{1}$N$_{1}$ influenza A virus particles. The results showed that GNPs were spherical, uniform shape, and approximately 10 nm in size. Noticeably, the complex of GNPs/PrA could detect and bind effectively to H$_{1}$N$_{1}$ influenza A virus particles by a large number of GNPs surrounded. The advantage of the complex of GNPs/PrA showed a highly potential application in biosensors with the improvement of the sensitivity and transducing signal for virus detection.

scholarly journals Study of Methylene Blue Degradation by Gold Nanoparticles Synthesized within Natural Zeolites

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ericka Rodríguez León ◽  
Eduardo Larios Rodríguez ◽  
César Rodríguez Beas ◽  
Germán Plascencia-Villa ◽  
Ramón Alfonso Iñiguez Palomares
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Gold Nanoparticles ◽  
Methylene Blue Degradation ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Scanning Transmission ◽  
Type Zeolite ◽  
Natural Clinoptilolite

We carried out thein situsynthesis of gold nanoparticles inside a natural clinoptilolite-type zeolite matrix, using ascorbic acid as reducing agent. The microstructure of both zeolite and zeolite-gold nanocomposite was characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and Energy-Dispersive X-ray Spectroscopy (EDS) techniques. Size distribution as assessed by STEM indicated that 60% of gold nanoparticles measured less than 2.5 nm. Determination of the surface area by the BET method revealed a specific value of 27.35 m2/g. The catalytic activity of zeolite-gold regarding methylene blue degradation under different light-exposing conditions was evaluated by UV-Vis spectroscopy. The results indicated that 50% degradation was achieved in only 11 min in presence of sunlight. This reaction was faster in comparison with those obtained using a white LED light. A notable aspect of this study is that catalysis was carried out without the addition of any strong reducing agents, such as sodium borohydride (NaBH4).

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