Seed-mediated synthesis and PEG coating of gold nanoparticles for controlling morphology and sizes

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3353-3360
Author(s):  
Susana Helena Arellano Ramírez ◽  
Perla García Casillas ◽  
Christian Chapa González
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Infrared Spectrometry ◽  
Ammonium Bromide ◽  
Chloroauric Acid ◽  
Vis Spectroscopy ◽  
Seed Mediated ◽  
Peg Coating

AbstractA significant area of research is biomedical applications of nanoparticles which involves efforts to control the physicochemical properties through simple and scalable processes. Gold nanoparticles have received considerable attention due to their unique properties that they exhibit based on their morphology. Gold nanospheres (AuNSs) and nanorods (AuNRs) were prepared with a seed-mediated method followed of polyethylene glycol (PEG)-coating. The seeds were prepared with 0.1 M cetyltrimethyl-ammonium bromide (CTAB), 0.005 M chloroauric acid (HAuCl4), and 0.01 M sodium borohydride (NaBH4) solution. Gold nanoparticles with spherical morphology was achieved by growth by aggregation at room temperature, while to achieve the rod morphology 0.1 M silver nitrate (AgNO3) and 0.1 M ascorbic acid solution were added. The gold nanoparticles obtained by the seed-mediated synthesis have spherical or rod shapes, depending on the experimental conditions, and a uniform particle size. Surface functionalization was developed using polyethylene glycol. Morphology, and size distribution of AuNPs were evaluated by Field Emission Scanning Electron Microscopy. The average size of AuNSs, and AuNRs was 7.85nm and 7.96 x 31.47nm respectively. Fourier transform infrared spectrometry was performed to corroborate the presence of PEG in the AuNPs surface. Additionally, suspensions of AuNSs and AuNRs were evaluated by UV-Vis spectroscopy. Gold nanoparticles were stored for several days at room temperature and it was observed that the colloidal stability increased once gold nanoparticles were coated with PEG due to the shield formed in the surface of the NPs and the increase in size which were 9.65±1.90 nm of diameter for AuNSs and for AuNRs were 29.03±5.88 and 8.39±1.02 nm for length and transverse axis, respectively.

Optimization of Gold Nanoparticles Synthesis using Design of Experiments Technique

2017 ◽  
Vol 68 (7) ◽  
pp. 1518-1423
Author(s):  
Adina Turcu Stiolica ◽  
Mariana Popescu ◽  
Maria Viorica Bubulica ◽  
Carmen Nicoleta Oancea ◽  
Claudiu Nicolicescu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Design Of Experiments ◽  
Process Model ◽  
Sodium Citrate ◽  
Drug Carriers ◽  
Chloroauric Acid ◽  
Gold Colloids ◽  
Citrate Concentration ◽  
Vis Spectroscopy

Gold nanoparticles are considered the newest drug carriers for different diseases. Therefore it is appropriate continuous optimization of their preparation. In this study, gold colloids with an average size of 1 - 26 nm were obtained by the reduction of tetrachloroauric acid with trisodium citrate. The nanomaterials were characterized by UV-Vis spectroscopy and dynamic light scattering technique. In addition, zeta potential was measured for samples synthesized in order to determine the stability of the colloids. A Two-level Full Factorial design was chosen to determine the optimum set of process parameters (chloroauric acid concentration and sodium citrate concentration) and their effect on various gold nanoparticles characteristics (size and zeta potential). These effects were quantified using Design of Experiments (DoE) with 5 runs and 1 centerpoint. The selected objective and process model in this investigation are screening and interaction. Findings from this research show that to obtain particles larger than 35 nm, it is recommended to increase sodium citrate concentration, at low chloroauric acid values. These conditions will help to achieve smaller zeta potential, too.

scholarly journals Controlled Synthesis of Gold Nanoparticles UsingAspergillus terreusIF0 and Its Antibacterial Potential against Gram Negative Pathogenic Bacteria

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Eepsita Priyadarshini ◽  
Nilotpala Pradhan ◽  
Lala B. Sukla ◽  
Prasanna K. Panda
Keyword(s):  
Gold Nanoparticles ◽  
Pathogenic Bacteria ◽  
Particle Diameter ◽  
Weight Fraction ◽  
Xrd Analysis ◽  
Controlled Synthesis ◽  
Chloroauric Acid ◽  
Gram Negative ◽  
Fungal Extract ◽  
Vis Spectroscopy

Biosynthesis of monodispersed nanoparticles, along with determination of potential responsible biomolecules, is the major bottleneck in the area of bionanotechnology research. The present study focuses on an ecofriendly, ambient temperature protocol for size controlled synthesis of gold nanoparticles, using the fungusAspergillus terreusIF0. Gold nanoparticles were formed immediately, with the addition of chloroauric acid to the aqueous fungal extract. Synthesized nanoparticles were characterized by UV-Vis spectroscopy, TEM-EDX, and XRD analysis. Particle diameter and dispersity of nanoparticles were controlled by varying the pH of the fungal extract. At pH 10, the average size of the synthesized particles was in the range of 10–19 nm. Dialysis to obtain high and low molecular weight fraction followed by FTIR analysis revealed that biomolecules larger than 12 kDa and having –CH, –NH, and –SH functional groups were responsible for bioreduction and stabilization. In addition, the synthesized gold nanoparticles were found to be selectively bactericidal against the pathogenic gram negative bacteria,Escherichia coli.

scholarly journals Room temperature seed mediated growth of gold nanoparticles: mechanistic investigations and life cycle assesment

2015 ◽  
Vol 2 (5) ◽  
pp. 440-453 ◽  
Author(s):  
Weinan Leng ◽  
Paramjeet Pati ◽  
Peter J. Vikesland
Keyword(s):  
Gold Nanoparticles ◽  
Life Cycle ◽  
Room Temperature ◽  
Gold Salt ◽  
Life Cycle Assesment ◽  
Seed Mediated ◽  
Mechanistic Investigations

In this study, we report the first room temperature seed-mediated synthesis of gold nanoparticles (AuNPs) in the presence of citrate and gold salt.

scholarly journals Arsenate reductase from Thermus thermophilus conjugated to polyethylene glycol-stabilized gold nanospheres allow trace sensing and speciation of arsenic ions

2016 ◽  
Vol 13 (123) ◽  
pp. 20160629 ◽  
Author(s):  
Jane Politi ◽  
Jolanda Spadavecchia ◽  
Gabriella Fiorentino ◽  
Immacolata Antonucci ◽  
Luca De Stefano
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Environmental Problem ◽  
Thermus Thermophilus ◽  
Arsenate Reductase ◽  
Gold Nanospheres ◽  
Enzyme Adsorption ◽  
Ph Values ◽  
Vis Spectroscopy ◽  
The World

Water sources pollution by arsenic ions is a serious environmental problem all around the world. Arsenate reductase enzyme ( TtArsC ) from Thermus thermophilus extremophile bacterium, naturally binds arsenic ions, As(V) and As (III), in aqueous solutions. In this research, TtArsC enzyme adsorption onto hybrid polyethylene glycol-stabilized gold nanoparticles (AuNPs) was studied at different pH values as an innovative nanobiosystem for metal concentration monitoring. Characterizations were performed by UV/Vis and circular dichroism spectroscopies, TEM images and in terms of surface charge changes. The molecular interaction between arsenic ions and the TtArsC -AuNPs nanobiosystem was also monitored at all pH values considered by UV/Vis spectroscopy. Tests performed revealed high sensitivities and limits of detection equal to 10 ± 3 M −12 and 7.7 ± 0.3 M −12 for As(III) and As(V), respectively.

Hybrid Microgels Containing Gold Nanoparticles

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Andrij Pich ◽  
Arpita Karak ◽  
Yan Lu ◽  
Anup K. Ghosh ◽  
Hans-Juergen P. Adler
Keyword(s):  
Gold Nanoparticles ◽  
Sodium Citrate ◽  
Colloidal Stability ◽  
Nano Particles ◽  
Composite Particles ◽  
Temperature Sensitive ◽  
Chloroauric Acid ◽  
Gold Nano Particles ◽  
Hybrid Microgels

AbstractIn present paper we report on a preparation of hybrid microgels filled with gold nano-particles (AuNPs). Temperature-sensitive VCL/AAEM microgels have been used as containers for deposition of Au by in situ formation of gold nano-particles. Synthesis of AuNPs has been performed by two methods: a) reduction of chloroauric acid with sodium borhydride and b) reduction of chloroauric acid by sodium citrate under ultrasonic agitation. In both cases AuNPs were deposited directly into microgels leading to formation of composite particles which exhibit temperature-sensitive properties, tunable gold contents and high colloidal stability. The influence of Au load on microgel size, morphology, swellingdeswelling behaviour and stability is discussed.

scholarly journals Role of Surfactant in the Formation of Gold Nanoparticles in Aqueous Medium

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Abhishek Das ◽  
Ridhima Chadha ◽  
Nandita Maiti ◽  
Sudhir Kapoor
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Medium ◽  
Sodium Dodecyl ◽  
Chloroauric Acid ◽  
Synthesis Mechanism ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The Stability ◽  
Mediated Reduction

The stability of gold nanoparticles is a major issue which decides their impending usage in nanobiotechnological applications. Often biomimetically synthesized nanoparticles are deemed useless owing to their instability in aqueous medium. So, surfactants are used to stabilize the nanoparticles. But does the surfactant only stabilize by being adsorbed to the surface of the nanoparticles and not play significantly in moulding the size and shape of the nanoparticles? Keeping this idea in mind, gold nanoparticles (GNPs) synthesized by l-tryptophan (Trp) mediated reduction of chloroauric acid (HAuCl4) were stabilized by anionic surfactant, sodium dodecyl sulphate (SDS), and its effect on the moulding of size and properties of the GNPs was studied. Interestingly, unlike most of the gold nanoparticles synthesis mechanism showing saturation growth mechanism, inclusion of SDS in the reaction mixture for GNPs synthesis resulted in a bimodal mechanism which was studied by UV-Vis spectroscopy. The mechanism was further substantiated with transmission electron microscopy. Zeta potential of GNPs solutions was measured to corroborate stability observations recorded visually.

scholarly journals Intratumoral generation of photothermal gold nanoparticles through a vectorized biomineralization of ionic gold

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Aaron S. Schwartz-Duval ◽  
Christian J. Konopka ◽  
Parikshit Moitra ◽  
Enrique A. Daza ◽  
Indrajit Srivastava ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Incubation Time ◽  
Biomedical Applications ◽  
Gold Clusters ◽  
Chloroauric Acid ◽  
Delivery Vector ◽  
Biomedical Potential ◽  
Ionic Gold

Abstract Various cancer cells have been demonstrated to have the capacity to form plasmonic gold nanoparticles when chloroauric acid is introduced to their cellular microenvironment. But their biomedical applications are limited, particularly considering the millimolar concentrations and longer incubation period of ionic gold. Here, we describe a simplistic method of intracellular biomineralization to produce plasmonic gold nanoparticles at micromolar concentrations within 30 min of application utilizing polyethylene glycol as delivery vector for ionic gold. We have characterized this process for intracellular gold nanoparticle formation, which progressively accumulates proteins as the ionic gold clusters migrate to the nucleus. This nano-vectorized application of ionic gold emphasizes its potential biomedical opportunities while reducing the quantity of ionic gold and required incubation time. To demonstrate its biomedical potential, we further induce in-situ biosynthesis of gold nanoparticles within MCF7 tumor mouse xenografts which is followed by its photothermal remediation.

scholarly journals Synthesis of Monodispersed Gold Nanoparticles with Exceptional Colloidal Stability with Grafted Polyethylene Glycol-g-polyvinyl Alcohol

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Alaaldin M. Alkilany ◽  
Alaa I. Bani Yaseen ◽  
Mohammed H. Kailani
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Colloidal Stability ◽  
Kinetic Mechanism ◽  
Grafted Copolymer ◽  
Synthesis Parameters ◽  
Salt Addition ◽  
One Step ◽  
Spherical Gold Nanoparticles

Herein, we report the synthesis of spherical gold nanoparticles with tunable core size (23–79 nm) in the presence of polyethylene glycol-g-polyvinyl alcohol (PEG-g-PVA) grafted copolymer as a reducing, capping, and stabilizing agent in a one-step protocol. The resulted PEG-g-PVA-capped gold nanoparticles are monodispersed with an exceptional colloidal stability against salt addition, repeated centrifugation, and extensive dialysis. The effect of various synthesis parameters and the kinetic/mechanism of the nanoparticle formation are discussed.

Photochemical transformations of thiolated polyethylene glycol coatings on gold nanoparticles

2016 ◽  
Vol 3 (5) ◽  
pp. 1090-1102 ◽  
Author(s):  
Stacey M. Louie ◽  
Justin M. Gorham ◽  
Eric A. McGivney ◽  
Jingyu Liu ◽  
Kelvin B. Gregory ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Gold Nanoparticle ◽  
Uv Irradiation ◽  
Colloidal Stability ◽  
Chain Scission ◽  
Photochemical Reactions ◽  
Surface Coatings ◽  
Photochemical Transformations ◽  
Thiolated Polyethylene Glycol

Photochemical reactions can cause significant transformations of manufactured nanomaterials and their surface coatings in sunlit environments. In this study, loss of thiolated polyethylene glycol from gold nanoparticle surfaces by chain scission was observed under UV irradiation and resulted in diminished colloidal stability.

scholarly journals Gold Nanoparticles Endowed with Low-Temperature Colloidal Stability by Cyclic Polyethylene Glycol in Ethanol

Soft Matter ◽  
2021 ◽  
Author(s):  
M. Ali Aboudzadeh ◽  
Joscha Kruse ◽  
Maria Sanromán-Iglesias ◽  
Daniele Cangialosi ◽  
Ángel Alegría ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Low Temperature ◽  
Thermal Behavior ◽  
Metal Nanoparticles ◽  
Polymer Brushes ◽  
Colloidal Stability ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature

The colloidal stability of metal nanoparticles is tremendously dependent on the thermal behavior of polymer brushes. Neat polyethylene glycol (PEG) presents an unconventional upper critical solution temperature in ethanol, where...

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