scholarly journals Tuning and tracking the growth of gold nanoparticles synthesized using binary surfactant mixtures

2020 ◽  
Vol 2 (5) ◽  
pp. 1980-1992
Author(s):  
Karthik Raghunathan ◽  
Jibin Antony ◽  
Sarmad Munir ◽  
Jens-Petter Andreassen ◽  
Sulalit Bandyopadhyay
Keyword(s):  
Gold Nanoparticles ◽  
Growth Mechanism ◽  
Surfactant Mixtures ◽  
Au Nps ◽  
Synthesis Parameters ◽  
First Time ◽  
Shape Transitions

The effects of synthesis parameters on the shape of gold nanoparticles (Au NPs) and their growth are investigated. A ternary space to study their shape transitions is reported for the first time. A growth mechanism based on supersaturation is proposed.

scholarly journals The role of OH− in the formation of highly selective gold nanowires at extreme pH: multi-fold enhancement in the rate of the catalytic reduction reaction by gold nanowires

2017 ◽  
Vol 19 (7) ◽  
pp. 5077-5090 ◽  
Author(s):  
Riham El Kurdi ◽  
Digambara Patra
Keyword(s):  
Gold Nanoparticles ◽  
Growth Mechanism ◽  
Catalytic Reduction ◽  
Reduction Reaction ◽  
Gold Nanowires ◽  
Au Nps

Illustration (not to scale) of the growth mechanism of gold nanoparticles (Au NPs) at pH 4 to 11 (left) and gold nanowires (Au NWs) at pH 13 (right), by reducing Au3+ to Au0 using curcumin in CTAB media in the presence of Ag+.

scholarly journals Microwave-assisted Synthesis of Hexagonal Gold Nanoparticles Reduced by Organosilane (3-Mercaptopropyl)trimethoxysilane

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1680 ◽  
Author(s):  
Kwok Wei Shah ◽  
Long Zheng
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Microwave Irradiation ◽  
Irradiation Time ◽  
Chemical Reduction ◽  
Microwave Assisted Synthesis ◽  
Au Nps ◽  
One Step ◽  
The Impact ◽  
First Time

A novel synthesis of hexagonal gold nanoparticles (Au NPs) via hydrolyzed organosilane (3-mercaptopropyl)trimethoxysilane (MPTMS) using an ultrafast and environmentally friendly method is presented in this study. For the first time, organosilane MPTMS is used for chemical reduction of auric acid under ultrafast microwave irradiation. To the best of our knowledge, the use of organosilane for the synthesis of Au NPs has not been reported. The entire one-step process is convenient, rapid and cost-effective, as well as eco-friendly under alcohol-free aqueous media. Different characterization methods were carried out to investigate the properties of synthesized gold nanoparticles. transmission electron microscopy and scanning electron microscopy were used to investigate the morphology of as-synthesized Au NPs, while X-ray powder diffraction was applied to obtain the crystalline nature. Nuclear magnetic resonance was used to track the hydrolysis of organosilane MPTMS, which is employed for the first time as a reducing agent for the synthesis of Au NPs. The impact from microwave irradiation time and power, as well as the catalytic property of as-synthesized Au NPs, was investigated via ultraviolet–visible spectroscopy. The as-synthesized products include gold nanohexagon and two-dimensional hexagonal gold nanoplatelets, both of which are single-crystal with (1 1 1) planes as basal surfaces. From UV-vis spectra, it is found that the facile water-based fabrication of hexagonal Au NPs began within seconds of microwave irradiation and the size growth increased with the microwave power and time. Moreover, the efficient reduction of 4-nitrophenol to 4-aminophenol in the presence of as-synthesized Au NPs was observed, exhibiting a remarkable catalytic activity. The present simple, rapid and convenient one-step microwave process possess high scalability and useful for future applications such as catalysis, medical, biological, plasmonic sensors and electronics.

Synthesis of noval gold nanomaterials and it's detection of sewage

2019 ◽  
Vol 14 (2) ◽  
pp. 365-370
Author(s):  
Furong Nie ◽  
Jun Ai
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Gold Nanoparticles ◽  
Pore Structure ◽  
Adsorption Experiment ◽  
Au Nps ◽  
Fluorescent Signal ◽  
Novel Approach ◽  
Gold Nanomaterials ◽  
First Time

Abstract In this article we report a novel approach to polyvinyl pyrrolidone k-30 (PVP)-templated formation of fluorescent gold nanoparticles (Au NPs) with pore structure and its application to sewage detection. For the first time the method of generating PVP-encapsulated Au NPs in aqueous solution is demonstrated. It was found that the formation of fluorescent Au NPs have highly fluorescent signal. Through the adsorption experiment, it is concluded that the methylene blue is adsorbed on Au NPs. This work successfully develops the capping PVP scaffolds of fluorescent Au NPs with pore structure. This experiment lays a foundation for the application of Au NPs in the field of environmental applications.

Synthesis of a silymarin-gold nanoparticle conjugate and analysis of its liver-protecting activity

2021 ◽  
Vol 22 ◽  
Author(s):  
Sergey Staroverov ◽  
Sergey Kozlov ◽  
Alexander Fomin ◽  
Konstantib Gabalov ◽  
Alexey Volkov ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Liver Disease ◽  
Carbon Tetrachloride ◽  
Glutathione Depletion ◽  
Laboratory Animals ◽  
Experimental Hepatitis ◽  
Acute Liver Disease ◽  
The Mean ◽  
Extent Of Damage ◽  
First Time

Background: The liver disease problem prompts investigators to search for new methods of liver treatment. Introduction: Silymarin (Sil) protects the liver by reducing the concentration of free radicals and the extent of damage to the cell membranes. A particularly interesting method to increase the bioavailability of Sil is to use synthesized gold nanoparticles (AuNPs) as reagents. The study considered whether it was possible to use the silymarin-AuNP conjugate as a potential liver-protecting drug. Method: AuNPs were conjugated to Sil and examine the liver-protecting activity of the conjugate. Experimental hepatitis and hepatocyte cytolysis after carbon tetrachloride actionwere used as a model system, and the experiments were conducted on laboratory animals. Result: For the first time, silymarin was conjugated to colloidal gold nanoparticles (AuNPs). Electron microscopy showed that the resultant preparations were monodisperse and that the mean conjugate diameter was 18–30 nm ± 0.5 nm (mean diameter of the native nanoparticles, 15 ± 0.5 nm). In experimental hepatitis in mice, conjugate administration interfered with glutathione depletion in hepatocytes in response to carbon tetrachloride was conducive to an increase in energy metabolism, and stimulated the monocyte–macrophage function of the liver. The results were confirmed by the high respiratory activity of the hepatocytes in cell culture. Conclusion: We conclude that the silymarin-AuNP conjugate holds promise as a liver-protecting agent in acute liver disease caused by carbon tetrachloride poisoning.

scholarly journals Easy and fast in-situ functionalization of exfoliated 2D black phosphorus with gold nanoparticles

2021 ◽  
Author(s):  
Salvatore Moschetto ◽  
Andrea Ienco ◽  
Gabriele Manca ◽  
Manuel Serrano-Ruiz ◽  
Maurizio Peruzzini ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Black Phosphorus ◽  
Au Nps ◽  
In Situ Functionalization

Heterostructures of single- and few-layer black phosphorus (2D bP) functionalized with gold nanoparticles (Au NPs) have been recently reported in the literature, exploiting their intriguing properties and biocompatibility for catalytic,...

scholarly journals Continuous citrate‐capped gold nanoparticle synthesis in a two‐phase flow reactor

2021 ◽  
Author(s):  
Spyridon Damilos ◽  
Ioannis Alissandratos ◽  
Luca Panariello ◽  
Anand N. P. Radhakrishnan ◽  
Enhong Cao ◽  
...  
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Residence Time ◽  
Flow Reactor ◽  
Phase Flow ◽  
Continuous Manufacturing ◽  
Two Phase ◽  
Process Yield ◽  
Au Nps ◽  
Manufacturing Platform

AbstractA continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10–20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 oC and 2.3 bar(a) pressure. The use of a two-phase flow system – using heptane as the continuous phase – prevented fouling on the reactor walls, while improving the residence time distribution. Continuous syntheses for up to 2 h demonstrated its potential application for continuous manufacturing, while live quality control was established using online UV-Vis photospectrometry that monitored the particle size and process yield. The synthesis was stable and reproducible over time for gold precursor concentration above 0.23 mM (after mixing), resulting in average particle size between 12 and 15 nm. A hydrophobic membrane separator provided successful separation of the aqueous and organic phases and collection of colloidal Au NPs in flow. Process yield increased at higher inlet flow rates (from 70 % to almost 100 %), due to lower residence time of the colloidal solution in the separator resulting in less fouling in the PTFE membrane. This study addresses the challenges for the translation of the synthesis from batch to flow and provides tools for the development of a continuous manufacturing platform for gold nanoparticles.Graphical abstract

scholarly journals Phosphatidylserine-Gold Nanoparticles (PS-AuNP) Induce Prostate and Breast Cancer Cell Apoptosis

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1094
Author(s):  
Allan Radaic ◽  
Nam E. Joo ◽  
Soo-Hwan Jeong ◽  
Seong-II Yoo ◽  
Nicholas Kotov ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Therapeutic Potential ◽  
Control Treatment ◽  
Track Record ◽  
Males And Females ◽  
Breast And Prostate Cancer ◽  
First Time

Prostate and breast cancer are the current leading causes of new cancer cases in males and females, respectively. Phosphatidylserine (PS) is an essential lipid that mediates macrophage efferocytosis and is dysregulated in tumors. Therefore, developing therapies that selectively restore PS may be a potential therapeutic approach for carcinogenesis. Among the nanomedicine strategies for delivering PS, biocompatible gold nanoparticles (AuNPs) have an extensive track record in biomedical applications. In this study, we synthesized biomimetic phosphatidylserine-caped gold nanoparticles (PS-AuNPs) and tested their anticancer potential in breast and prostate cancer cells in vitro. We found that both cell lines exhibited changes in cell morphology indicative of apoptosis. After evaluating for histone-associated DNA fragments, a hallmark of apoptosis, we found significant increases in DNA fragmentation upon PS-AuNP treatment compared to the control treatment. These findings demonstrate the use of phosphatidylserine coupled with gold nanoparticles as a potential treatment for prostate and breast cancer. To the best of our knowledge, this is the first time that a phosphatidylserine-capped AuNP has been examined for its therapeutic potential in cancer therapy.

Macroscopical monolayer films of ordered arrays of gold nanoparticles as SERS substrates for in-situ quantitative detection in aqueous solutions

Nanoscale ◽  
2021 ◽  
Author(s):  
Lixiang Xing ◽  
Cui Wang ◽  
Yi Cao ◽  
Jihui Zhang ◽  
Haibing Xia
Keyword(s):  
Gold Nanoparticles ◽  
Volume Fraction ◽  
Water Volume ◽  
Quantitative Detection ◽  
Monolayer Films ◽  
Au Nps ◽  
Sers Substrates ◽  
Ordered Arrays ◽  
Water Volume Fraction

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of...

scholarly journals Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Viability ◽  
Leaf Extract ◽  
Room Temperature ◽  
Klebsiella Oxytoca ◽  
Cost Effective ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Inhibition Concentration ◽  
First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

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.

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