scholarly journals The role of pre-nucleation clusters in the crystallization of gold nanoparticles

Nanoscale ◽  
2020 ◽  
Vol 12 (30) ◽  
pp. 16173-16188 ◽  
Author(s):  
Raj Kumar Ramamoorthy ◽  
Ezgi Yildirim ◽  
Enguerrand Barba ◽  
Pierre Roblin ◽  
Jorge A. Vargas ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Nucleation Mechanism ◽  
Nucleation Stage

The gold nanoparticle nucleation stage identified by XAS is accompanied in SAXS by an abrupt shrinkage of the size of molecular pre-nucleation clusters into gold nuclei, which is interpreted as a non-classical nucleation mechanism.

scholarly journals Innovative gold nanoparticle patterning and selective metallization

2013 ◽  
Vol 1547 ◽  
pp. 149-154
Author(s):  
E.S. Kooij ◽  
M.A. Raza ◽  
H.J.W. Zandvliet
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Pure Water ◽  
Water Molecules ◽  
Thiol Groups ◽  
Seeded Growth ◽  
Self Assembled Layer ◽  
High Degree ◽  
Metal Layers

ABSTRACTWe present a simple, novel procedure to selectively deposit gold nanoparticles using pure water. It enables patterning of nanoparticle monolayers with a remarkably high degree of selectivity on flat as well as microstructured oxide surfaces. We demonstrate that water molecules form a thin ‘capping’ layer on exposed thiol molecules within the mercaptan self-assembled layer. This reversible capping of water molecules locally ‘deactivates’ the thiol groups, therewith inhibiting the binding of metallic gold nanoparticles to these specific areas. In addition, we show that this amazing role of water molecules can be used to selectively metalize the patterned gold nanoparticle arrays. Employing an electroless seeded growth process, the isolated seeds are enlarged past the percolation threshold to deposit conducting metal layers.

scholarly journals Near-Infrared-Responsive Cancer Photothermal and Photodynamic Therapy Using Gold Nanoparticles

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 961 ◽  
Author(s):  
Hyung Kim ◽  
Dong Lee
Keyword(s):  
Gold Nanoparticles ◽  
Cancer Therapy ◽  
Gold Nanoparticle ◽  
Near Infrared ◽  
Energy Conversion Efficiency ◽  
Biological Properties ◽  
Drug Delivery Carrier ◽  
Thermal Energy Conversion ◽  
Gold Nanocomposites

Rapid growth of nanotechnology is one of the most quickly emerging tendencies in cancer therapy. Gold nanoparticles roused a distinctive interest in the field, due to their incomparable light-to-thermal energy conversion efficiency, and their ability to load and deliver a variety of anticancer drugs. Therefore, simultaneous photothermal (PTT) and photodynamic (PDT) cancer therapy is available by the role of the thermal agent of the gold nanoparticle itself and the drug delivery carrier for photosensitizer (PS) transport. In this review, the physical, chemical, and biological properties of gold nanoparticle, which can promote PTT and PDT efficiency, are briefly demonstrated, and we highlight recent progression in the development of PS-containing gold nanocomposites for effective cancer therapy.

scholarly journals Sinter-resistant gold nanoparticles encapsulated by zeolite nanoshell for oxidation of cyclohexane

RSC Advances ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 8015-8020 ◽  
Author(s):  
Shilpi Saxena ◽  
Rupesh Singh ◽  
Raj Ganesh S. Pala ◽  
Sri Sivakumar
Keyword(s):  
Gold Nanoparticles ◽  
Hydrothermal Synthesis ◽  
Gold Nanoparticle ◽  
Au Nanoparticles ◽  
Cyclohexane Oxidation

We report hydrothermal synthesis of sinter-resistant gold nanoparticle encapsulated by zeolite shells, which serve the role of stabilizing Au nanoparticles against sintering during cyclohexane oxidation.

Interference of Gold Nanoparticles with In vitro Endotoxin Detection Assays

2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Surface Reactivity ◽  
In Vitro Assays ◽  
Limulus Amebocyte Lysate ◽  
Chromogenic Assay ◽  
Nanoparticle Suspensions ◽  
Endotoxin Contamination ◽  
Factor C

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.

Key Role of the Oxidized Citrate-Free Radical in the Nucleation Mechanism of the Metal Nanoparticle Turkevich Synthesis

2019 ◽  
Vol 123 (36) ◽  
pp. 22624-22633 ◽  
Author(s):  
Sarah Al Gharib ◽  
Jean-Louis Marignier ◽  
Abdel Karim El Omar ◽  
Adnan Naja ◽  
Sophie Le Caer ◽  
...  
Keyword(s):  
Free Radical ◽  
Nucleation Mechanism ◽  
Metal Nanoparticle

scholarly journals CRISPR/Cas12a-mediated gold nanoparticle aggregation for colorimetric detection of SARS-CoV-2

2021 ◽  
Author(s):  
Yiren Cao ◽  
Jinjun Wu ◽  
Bo Pang ◽  
Hongquan Zhang ◽  
X. Chris Le
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Colorimetric Detection ◽  
Isothermal Amplification ◽  
Nanoparticle Aggregation ◽  
Cleavage Activity ◽  
Gold Nanoparticle Aggregation

The trans-cleavage activity of the target-activated CRISPR-Cas12a liberated an RNA crosslinker from a molecular transducer, which facilitated assembly of gold nanoparticles. Integration of the molecular transducer with isothermal amplification and...

Fluorescence biosensor for Salmonella typhimurium detection in food based on nano-self-assembly of alendronic acid modified upconversion and gold nanoparticles

2021 ◽  
Author(s):  
Min Chen ◽  
Leiqing Pan ◽  
K. Tu
Keyword(s):  
Gold Nanoparticles ◽  
Salmonella Typhimurium ◽  
Gold Nanoparticle ◽  
Alendronic Acid ◽  
Self Assembly ◽  
Upconversion Nanoparticles ◽  
Fluorescent Biosensor ◽  
Fluorescence Biosensor

A simple and quick responsive fluorescent biosensor for Salmonella typhimurium detection based on the recognition of aptamer coupled with alendronic acid (ADA)@upconversion nanoparticles (UCNPs) and gold nanoparticle (AuNPs) has been...

scholarly journals Enhanced Extracellular Synthesis of Gold Nanoparticles by Soluble Extracts from Escherichia coli Transformed with Rhizobium tropici Phytochelatin Synthase Gene

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 472
Author(s):  
Qunying Yuan ◽  
Manjula Bomma ◽  
Zhigang Xiao
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Synthesis Method ◽  
Nanoparticle Synthesis ◽  
Morphological Properties ◽  
Phytochelatin Synthase ◽  
Rhizobium Tropici ◽  
Whole Cells ◽  
E Coli ◽  
Recombinant Cells

Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.

scholarly journals Enhanced enzymatic activity from phosphotriesterase trimer gold nanoparticle bioconjugates for pesticide detection

The Analyst ◽  
2017 ◽  
Vol 142 (17) ◽  
pp. 3261-3271 ◽  
Author(s):  
John A. Hondred ◽  
Joyce C. Breger ◽  
Nate T. Garland ◽  
Eunkeu Oh ◽  
Kimihiro Susumu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Activity ◽  
Gold Nanoparticle ◽  
Pesticide Detection

A significant enzymatic enhancement of phosphotriesterase has been demonstrated when immobilized on various sized gold nanoparticles.

The Role of Silver and Gold Nanoparticles in Enhancing Luminescence of Europium Complexes

2014 ◽  
Vol 14 (6) ◽  
pp. 4357-4362 ◽  
Author(s):  
Hongyan Zhao ◽  
Feng Song ◽  
Fengxiao Wang ◽  
Jiadong Liu ◽  
Yanling Liu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Europium Complexes ◽  
Silver And Gold Nanoparticles
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