Biocompatible d-penicillamine conjugated Au nanoparticles: targeting intracellular free copper ions for detoxification

Electrochemical carbonylation of phenol (PhOH) with CO (1 atm) to form diphenyl carbonate (DPC) was studied by using a Pd-(in situ NHC) electrocatalyst and graphene-supported Au nanoparticle (Au NPs/GR) anodes.

Download Full-text

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

Current Catalysis ◽

10.2174/2211544708666190124114519 ◽

2019 ◽

Vol 8 (1) ◽

pp. 56-61

Author(s):

Aneeya K. Samantara ◽

Debasrita Dash ◽

Dipti L. Bhuyan ◽

Namita Dalai ◽

Bijayalaxmi Jena

Keyword(s):

Electron Transfer ◽

Photocatalytic Activity ◽

Visible Light ◽

Transfer Rate ◽

Photocatalytic Performance ◽

Light Exposure ◽

Au Nanoparticle ◽

Electron Transfer Rate ◽

Au Nps ◽

Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

Download Full-text

Fabrication and Application of SERS-Active Cellulose Fibers Regenerated from Waste Resource

Polymers ◽

10.3390/polym13132142 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2142

Author(s):

Shengjun Wang ◽

Jiaqi Guo ◽

Yibo Ma ◽

Alan X. Wang ◽

Xianming Kong ◽

...

Keyword(s):

Au Nanoparticles ◽

Cellulose Fiber ◽

Cellulose Fibers ◽

Regenerated Cellulose ◽

Sers Substrate ◽

Au Nps ◽

Convenient Approach ◽

Theoretical Simulations ◽

Difference Time ◽

Raman Probe

The flexible SERS substrate were prepared base on regenerated cellulose fibers, in which the Au nanoparticles were controllably assembled on fiber through electrostatic interaction. The cellulose fiber was regenerated from waste paper through the dry-jet wet spinning method, an eco-friendly and convenient approach by using ionic liquid. The Au NPs could be controllably distributed on the surface of fiber by adjusting the conditions during the process of assembling. Finite-difference time-domain theoretical simulations verified the intense local electromagnetic fields of plasmonic composites. The flexible SERS fibers show excellent SERS sensitivity and adsorption capability. A typical Raman probe molecule, 4-Mercaptobenzoicacid (4-MBA), was used to verify the SERS cellulose fibers, the sensitivity could achieve to 10−9 M. The flexible SERS fibers were successfully used for identifying dimetridazole (DMZ) from aqueous solution. Furthermore, the flexible SERS fibers were used for detecting DMZ from the surface of fish by simply swabbing process. It is clear that the fabricated plasmonic composite can be applied for the identifying toxins and chemicals.

Download Full-text

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

Journal of Nanoparticles ◽

10.1155/2013/841582 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5 ◽

Cited By ~ 4

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.

Download Full-text

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

Nanoscale ◽

10.1039/d1nr01272j ◽

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...

Download Full-text

A novel photoelectrode based on eosin Y–rhodamine B duo-dye sensitized Au nanoparticles by in situ reduction

Analytical Methods ◽

10.1039/c7ay01743j ◽

2017 ◽

Vol 9 (38) ◽

pp. 5586-5592 ◽

Cited By ~ 3

Author(s):

Y. L. Yuan ◽

G. M. Pang ◽

X. K. Li ◽

W. Y. Zhu ◽

H. C. Pan

Keyword(s):

Rhodamine B ◽

Au Nanoparticles ◽

Specific Response ◽

Eosin Y ◽

In Situ Reduction ◽

Au Nps ◽

Dye Sensitized ◽

Novel Strategy

A novel strategy for the fabrication of a photoelectrochemical system, involving a duo-dye sensitized Au NPs composite, that displays a specific response to mercury.

Download Full-text

Effect of Conditions of Sol-Gel Synthesis and Post-Synthetic Treatment on Photoelectrochemical and Electro-Catalytic Properties of Titanium Oxide Nanostructures and Tio2-Au Nanocomposites

Elektronnaya Obrabotka Materialov ◽

10.52577/eom.2021.57.4.01 ◽

2021 ◽

Vol 57 (4) ◽

pp. 1-14

Author(s):

N.I. Romanovska ◽

◽

P.A. Manorik ◽

V.S. Vorobets ◽

G.Ya. Kolbasov ◽

...

Keyword(s):

Visible Light ◽

Au Nanoparticles ◽

Sol Gel ◽

Au Nanoparticle ◽

Chemical Compositions ◽

High Catalytic Activity ◽

Electron Microscopies ◽

Treatment Conditions ◽

Carboxylate Groups ◽

Tio2 Nanostructures

Carbon-doped mesoporous TiO2 nanostructures and TiO2-Au nanocomposites with stabilized Au nanoparticles have been synthesized by the sol-gel template method and characterized by X-ray diffraction, scanning and transmission electron microscopies, Fourier-transform infrared spectroscopy, N2 adsorption/desorption, ultraviolet-visible spectroscopy, and photoelectrochemical current spectroscopy. The synthesis hydrothermal treatment conditions affected the particle size, electronic structure, morphology, phase, and chemical compositions, as well as the texture of the synthesized materials. The TiO2 and TiO2-Au based electrodes were light-sensitive in a wavelength range of 250–412 nm and were distinguished by a high catalytic activity during oxygen electroreduction. The presence of -ol and carboxylate groups in the amorphous phase is the main factor affecting the photosensitivity of TiO2 nanostructures to visible light and an increase in their photoactivity during the decomposition of methylene blue upon irradiation with ultraviolet and visible light relative to pure anatase. The higher photosensitivity and photoactivity of TiO2-Au nanocomposites compared with those of the corresponding starting TiO2 is due to the synergistic effect of Au nanoparticles and interstitial Ti-O-C groups, which depends on the Au nanoparticle content of the composite and on the mesopore size.

Download Full-text

Sensitive Hg2+ Ion Detection Using Metal Enhanced Fluorescence of Novel Polyvinyl Pyrrolidone (PVP)-Templated Gold Nanoparticles

Applied Spectroscopy ◽

10.1177/0003702818775704 ◽

2018 ◽

Vol 72 (11) ◽

pp. 1645-1652 ◽

Cited By ~ 6

Author(s):

Kailong Dong ◽

Jiasheng Zhou ◽

Taiqun Yang ◽

Shan Dai ◽

Hao Tan ◽

...

Keyword(s):

Gold Nanoparticles ◽

Detection Limit ◽

Au Nanoparticles ◽

Polyvinyl Pyrrolidone ◽

Quenching Mechanism ◽

Ion Detection ◽

Enhanced Fluorescence ◽

Metal Enhanced Fluorescence ◽

One Pot ◽

Au Nps

In this study, we report a straightforward strategy for Hg2+ ion detection. Fluorescent Au nanoparticles (NPs) were one-pot synthesized using a polymer (polyvinyl pyrrolidone [PVP]) as both capping and fluorescence agent. The as-synthesized PVP-Au NPs showed a remarkably rapid response selectively for Hg2+ ions compared to 14 other metal ions. The detection limit of Hg2+ was estimated at 100 nM. We discuss the emission and quenching mechanism of the PVP-Au NPs, the former being attributed to metal enhanced fluorescence and the latter being related to static quenching by Hg2+. The fluorescence of PVP-Au NPs offers an efficient and reliable strategy for Hg2+ ions detection. They therefore have a great potential for applications in health and environmental monitoring.

Download Full-text

CO Total and Preferential Oxidation over Stable Au/TiO2 Catalysts Derived from Preformed Au Nanoparticles

Catalysts ◽

10.3390/catal10091028 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1028

Author(s):

Núria J. Divins ◽

Eduardo López ◽

Inmaculada Angurell ◽

Stefan Neuberg ◽

Ralf Zapf ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Au Nanoparticles ◽

Gold Catalyst ◽

Space Velocity ◽

Ex Situ ◽

Oxidation Reactions ◽

Preferential Oxidation ◽

Au Nps ◽

Tio2 Anatase ◽

Operation Conditions

CO preferential oxidation (PROX) is an effective method to clean reformate H2 streams to feed low-temperature fuel cells. In this work, the PROX and CO oxidation reactions were studied on preformed Au nanoparticles (NPs) supported on TiO2 anatase. Preformed Au NPs were obtained from gold cores stabilized by dodecanethiols or trimethylsilane-dendrons. A well-controlled size of ca. 2.6 nm and narrow size distributions were achieved by this procedure. The catalysts were characterized by high-resolution transmission electron microscopy and ex situ and in situ X-ray photoelectron spectroscopy (XPS). The XPS results showed that the preformed Au NPs exhibited high thermal stability. The different ligand-derived Au catalysts, as well as a conventional gold catalyst for comparison purposes, were loaded onto cordierite supports with 400 cells per square inch. The activity and selectivity of the samples were evaluated for various operation conditions. The catalyst prepared using dodecanethiol-capped Au NPs showed the best performance. In fact, CO conversions of up to 70% at 40% CO2 selectivity and 90% O2 conversion were observed operating at 363 K in H2-rich atmospheres. The performance of the best catalysts was subsequently tested on stainless steel microreactors. A 500-hour stability test was carried out under a real post-reformate stream, including 18 vol.% CO2 and 29 vol.% H2O. A mean CO conversion of ca. 24% was measured for the whole test operating at 453 K and a gas hourly space velocity (GHSV) of 1.3 × 104 h−1. These results reveal our dodecanethiol- and carbosilane-derived Au catalysts as extremely promising candidates to conduct a PROX reaction while avoiding deactivation, which is one of the major drawbacks of Au/TiO2 catalysts.

Download Full-text