Synthesis of gold nanoparticles and nanoclusters in a supramolecular gel and their applications in catalytic reduction of p-nitrophenol to p-aminophenol and Hg(ii) sensing

RSC Advances ◽  
2014 ◽  
Vol 4 (85) ◽  
pp. 45449-45457 ◽  
Author(s):  
Dhurjati Prasad Kumar
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Catalytic Reduction ◽  
Au Nanoparticle ◽  
Au Nanoclusters ◽  
Supramolecular Gel ◽  
Supramolecular Gels

Seven gelator molecules giving supramolecular gels produced Au-nanoparticles and fluorescent, small Au-nanoclusters. Such Au-nanoparticle containing gels catalyzed the reduction of p-nitrophenol to p-aminophenol without NaBH4. The fluorescent Au-nanoclusters acted as a Hg(ii) sensor.

scholarly journals Thermal atomic layer deposition of gold nanoparticles: controlled growth and size selection for photocatalysis

Nanoscale ◽  
2020 ◽  
Vol 12 (16) ◽  
pp. 9005-9013 ◽  
Author(s):  
Fatemeh S. M. Hashemi ◽  
Fabio Grillo ◽  
Vikram R. Ravikumar ◽  
Dominik Benz ◽  
Ankit Shekhar ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Atomic Layer Deposition ◽  
Fluidized Bed ◽  
Au Nanoparticles ◽  
Atomic Layer ◽  
Fluidized Bed Reactor ◽  
Au Nanoparticle ◽  
Pulse Time ◽  
Layer Deposition ◽  
Selection For

Thermal atomic layer deposition of Au nanoparticles on titania in a fluidized bed reactor. Effects of precursor pulse time on Au nanoparticle size and loading.

scholarly journals Polydopamine as a bridge to decorate monodisperse gold nanoparticles on Fe3O4 nanoclusters for the catalytic reduction of 4-nitrophenol

RSC Advances ◽  
2017 ◽  
Vol 7 (72) ◽  
pp. 45545-45551 ◽  
Author(s):  
Shili Liu ◽  
Aori Qileng ◽  
Junying Huang ◽  
Qiongzhi Gao ◽  
Yingju Liu
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Catalytic Reduction ◽  
Good Stability

The in situ assembly of Au nanoparticles on Fe3O4@PDA showed excellent recyclability and good stability for the catalytic reduction of 4-nitrophenol.

scholarly journals Six-fold plasmonic enhancement of thermal scavenging via CsPbBr3 anti-Stokes photoluminescence

Nanophotonics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 599-605 ◽  
Author(s):  
Benjamin J. Roman ◽  
Matthew T. Sheldon
Keyword(s):  
Gold Nanoparticles ◽  
Thermal Energy ◽  
Au Nanoparticles ◽  
Fold Increase ◽  
Au Nanoparticle ◽  
Plasmonic Enhancement ◽  
Limited Region ◽  
Confocal Fluorescence ◽  
Bare Substrate ◽  
Anti Stokes

AbstractOne-photon up-conversion, also called anti-Stokes photoluminescence (ASPL), is the process whereby photoexcited carriers scavenge thermal energy and are promoted into a higher energy excited state before emitting a photon of greater energy than initially absorbed. Here, we examine how ASPL from CsPbBr3 nanoparticles is modified by coupling with plasmonically active gold nanoparticles deposited on a substrate. Two coupling regimes are examined using confocal fluorescence microscopy: three to four Au nanoparticles per diffraction limited region and monolayer Au nanoparticle coverage of the substrate. In both regimes, CsPbBr3 ASPL is blue-shifted relative to CsPbBr3 deposited on a bare substrate, corresponding to an increase in the thermal energy scavenged per emitted photon. However, with monolayer Au nanoparticle coverage, ASPL is enhanced relative to the conventional Stokes-shifted PL. Together, these phenomena result in a 6.7-fold increase in the amount of thermal energy extracted from the system during optical absorption and reemission.

An Effort to Making a Colorimitric Nano-Biosensor for Vibrio cholera Detection

2020 ◽  
Vol 16 (5) ◽  
pp. 793-804
Author(s):  
Naimeh Mahheidari ◽  
Jamal Rashidiani ◽  
Hamid Kooshki ◽  
Khadijeh Eskandari
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Assay ◽  
Au Nanoparticle ◽  
Bacteria Detection ◽  
Great Promise ◽  
Bacterial Cells ◽  
Vibrio Cholera ◽  
Minimum Concentration ◽  
Vis Spectroscopy ◽  
Fast Procedure

Background: Today, nanoparticles hold great promise in biomedical researches and applications including bacteria detection. The rapid and sensitive outcomes of bacteria detection strategies using nanoparticle conjugates become determinative, especially in bacterial outbreaks. In the current research, we focused on detecting V. cholera bacteria and its toxin using a thiocyanate/Au nanoparticle. Thiocyanate adsorbed strongly on the surface of gold nanoparticles and changed the surface by enhancing surface plasmon resonance of gold nanoparticles. Objective: This method is tried to introduce a simple and fast procedure to assay vibrio cholera. So, it is observed by the naked eyes as well. Methods: We used two antibodies (Ab) for V. cholera detection: a) a primary antibody conjugated to magnetic nanoparticles (MNPs) for trapping V. cholera bacterial cells, and b) a secondary Abconjugated thiocyanate-GNPs as a colorimetric detector. Then, an immuno-magnetic separation system connected to a colorimetric assay was designed based on the GNPs. The results were measured by ultraviolet-visible (UV-Vis) spectroscopy. Results: The results showed that gold nanoparticles are an appropriate optical assay for detecting biological samples in a minimum concentration and also it can be easily seen by the naked eyes. The linear range of this biosensor is 3.2×104 to 28×104 cells per ml. Conclusion: In this research, a colorimetric immune assay based on gold nanoparticles was designed to improve the sensitivity of V. cholera detection. Also, this method can be used for the detection of other biological agents.

The Stabilization of Supported Au Nanoparticles in a Highly Sintering Environment using High Surface Free Energy Pt and Ru Cores

2021 ◽  
Author(s):  
Kerry O-Connell ◽  
John R Monnier ◽  
John Regalbuto
Keyword(s):  
Gold Nanoparticles ◽  
Free Energy ◽  
Surface Free Energy ◽  
Au Nanoparticles ◽  
High Surface ◽  
Chemical Environment ◽  
Core Shell

In an effort to stabilize gold nanoparticles which sinter rapidly in a highly corrosive chemical environment, the hydrochlorination of acetylene, bimetallic Ru@Au and Pt@Au core-shell catalysts were prepared by anchoring...

scholarly journals Electroless Deposited Gold Nanoparticles on Glass Plates as Sensors for Measuring the Dielectric Constant of Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Y. Kobayashi ◽  
Y. Ishii
Keyword(s):  
Dielectric Constant ◽  
Au Nanoparticles ◽  
Glass Plate ◽  
Au Nanoparticle ◽  
Peak Wavelength ◽  
Nanoparticle Deposition ◽  
Metal Plating ◽  
Large Dielectric Constant ◽  
Electroless Metal Plating ◽  
Glass Plates

This work describes a method for the deposition of Au nanoparticles on glass plates (Au-glass). An electroless metal plating technique was extended to the Au nanoparticle deposition. The technique consisted of three steps that took place on the glass plate: (1) adsorption of Sn2+ ions, (2) deposition of metallic Ag nuclei generated by reducing Ag+ ions with Sn2+ ions on the Sn-adsorbed sites, and (3) deposition of Au nanoparticles by reducing Au+ ions on the Ag surface. TEM observation revealed that metallic Au nanoparticles with a size of  nm were formed on the glass surface. A surface plasmon resonance absorption peak was observed, and its peak wavelength redshifted by immersing the Au-glass into a solution with a large dielectric constant. The redshift corresponded qualitatively to the calculation by the Mie theory accompanying the Drude expression, which was based on the change of the dielectric constant of the solution. The obtained results indicated that the Au-glass functioned as a sensor for measuring the dielectric constant of the solution.

scholarly journals Structural characterization of functionalized gold nanoparticles for drug delivery in cancer therapy: a NMR based approach

2015 ◽  
Vol 17 (29) ◽  
pp. 18971-18979 ◽  
Author(s):  
Sílvia C. Coelho ◽  
Maria Rangel ◽  
Maria C. Pereira ◽  
Manuel A. N. Coelho ◽  
Galya Ivanova
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Cancer Therapy ◽  
Structural Characterization ◽  
Au Nanoparticles ◽  
Functionalized Gold Nanoparticles ◽  
Loaded Surface

Structure of Bortezomib loaded, surface functionalized Au nanoparticles.

scholarly journals Green Synthesis of Silver and Gold Nanoparticles via Sargassum serratifolium Extract for Catalytic Reduction of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Catalytic Reduction ◽  
Organic Dyes ◽  
Low Cost ◽  
Inorganic Nanoparticles ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sargassum Serratifolium

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.

Coalescence and shape oscillations of Au nanoparticles in CO2 hydrogenation for methanol reaction

Nanoscale ◽  
2021 ◽  
Author(s):  
Shengnan Yue ◽  
Yongli Shen ◽  
Ziliang Deng ◽  
Wenjuan Yuan ◽  
Wei Xi
Keyword(s):  
Au Nanoparticles ◽  
High Selectivity ◽  
Co2 Hydrogenation ◽  
Au Nanoparticle ◽  
Limited Knowledge ◽  
Shape Oscillations

Recently, there has been renewed interest in Au nanoparticle (Au NP) catalysts owing to their high selectivity for CO2 hydrogenation to methanol. However, there is still limited knowledge on the...

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