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 Nitrone Modified Gold Nanoparticles: Synthesis, Characterization and Their Potential as 18F-Labeled PET Probes via I-SPANC

2019 ◽  
Author(s):  
Sara Ghiassian ◽  
Lihai Yu ◽  
Pierangelo Gobbo ◽  
Ali nazemi ◽  
Tommaso Romagnoli ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Nmr Spectroscopy ◽  
Gold Nanoparticle ◽  
Molecular Level ◽  
Prosthetic Group ◽  
H Nmr ◽  
Nanoparticles Synthesis ◽  
Interfacial Strain ◽  
Pet Probes ◽  
High Degree

A bioorthogonal gold nanoparticle template displaying interfacial nitrone functional groups for bioorthogonal interfacial strain-promoted alkyne-nitrone cycloaddition (I-SPANC) reactions has been synthesized. The Nitrone-AuNPs were characterized in detail using <sup>1</sup>H NMR spectroscopy, TEM, TGA, and XPS and a nanoparticle raw formula was calculated. The ability to control the conjugation of molecules of interest at the molecular level onto the Nitrone-AuNPs template allowed us to create a methodology for the synthesis of AuNP-based radiolabeled probes with a high degree of loading using copper free, strained-promoted cycloaddition. To this end, we also describe the synthesis of a new prosthetic group containing a strained-alkyne capable of clicking hot <sup>18</sup>F-label onto complementary azide or nitrone labelled agents.

scholarly journals Nitrone Modified Gold Nanoparticles: Synthesis, Characterization and Their Potential as 18F-Labeled PET Probes via I-SPANC

2019 ◽  
Author(s):  
Sara Ghiassian ◽  
Lihai Yu ◽  
Pierangelo Gobbo ◽  
Ali nazemi ◽  
Tommaso Romagnoli ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Nmr Spectroscopy ◽  
Gold Nanoparticle ◽  
Molecular Level ◽  
Prosthetic Group ◽  
H Nmr ◽  
Nanoparticles Synthesis ◽  
Interfacial Strain ◽  
Pet Probes ◽  
High Degree

A bioorthogonal gold nanoparticle template displaying interfacial nitrone functional groups for bioorthogonal interfacial strain-promoted alkyne-nitrone cycloaddition (I-SPANC) reactions has been synthesized. The Nitrone-AuNPs were characterized in detail using <sup>1</sup>H NMR spectroscopy, TEM, TGA, and XPS and a nanoparticle raw formula was calculated. The ability to control the conjugation of molecules of interest at the molecular level onto the Nitrone-AuNPs template allowed us to create a methodology for the synthesis of AuNP-based radiolabeled probes with a high degree of loading using copper free, strained-promoted cycloaddition. To this end, we also describe the synthesis of a new prosthetic group containing a strained-alkyne capable of clicking hot <sup>18</sup>F-label onto complementary azide or nitrone labelled agents.

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.

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.

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.

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 Mechanism of porphobilinogen synthase. Possible role of essential thiol groups.

1977 ◽  
Vol 252 (24) ◽  
pp. 8965-8974 ◽  
Author(s):  
G.F. Barnard ◽  
R. Itoh ◽  
L.H. Hohberger ◽  
D. Shemin
Keyword(s):  
Thiol Groups ◽  
Porphobilinogen Synthase

scholarly journals Substrate wettability guided oriented self assembly of Janus particles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meneka Banik ◽  
Shaili Sett ◽  
Chirodeep Bakli ◽  
Arup Kumar Raychaudhuri ◽  
Suman Chakraborty ◽  
...  
Keyword(s):  
Self Assembly ◽  
Janus Particles ◽  
Water Molecules ◽  
Functional Coatings ◽  
Hexagonal Close Packed ◽  
Local Densities ◽  
Inhomogeneous Properties ◽  
Metal Polymer ◽  
Specific Orientation

AbstractSelf-assembly of Janus particles with spatial inhomogeneous properties is of fundamental importance in diverse areas of sciences and has been extensively observed as a favorably functionalized fluidic interface or in a dilute solution. Interestingly, the unique and non-trivial role of surface wettability on oriented self-assembly of Janus particles has remained largely unexplored. Here, the exclusive role of substrate wettability in directing the orientation of amphiphilic metal-polymer Bifacial spherical Janus particles, obtained by topo-selective metal deposition on colloidal Polymestyere (PS) particles, is explored by drop casting a dilute dispersion of the Janus colloids. While all particles orient with their polymeric (hydrophobic) and metallic (hydrophilic) sides facing upwards on hydrophilic and hydrophobic substrates respectively, they exhibit random orientation on a neutral substrate. The substrate wettability guided orientation of the Janus particles is captured using molecular dynamic simulation, which highlights that the arrangement of water molecules and their local densities near the substrate guide the specific orientation. Finally, it is shown that by spin coating it becomes possible to create a hexagonal close-packed array of the Janus colloids with specific orientation on differential wettability substrates. The results reported here open up new possibilities of substrate-wettability driven functional coatings of Janus particles, which has hitherto remained unexplored.

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