Simply amplificated signal in electrochemiluminescence sensor using nano-gold film as a bridge

2021 ◽  
pp. 106887
Author(s):  
Xueling Shan ◽  
Qingyuan Song ◽  
Chang Su ◽  
Chunping Dong ◽  
Ding Jiang ◽  
...  
Keyword(s):  
Gold Film ◽  
Nano Gold

Contrast from epitaxially sandwiched macromolecules

1978 ◽  
Vol 36 (2) ◽  
pp. 226-227
Author(s):  
M. Talianker ◽  
D.G. Brandon
Keyword(s):  
Gold Film ◽  
Lattice Defect ◽  
Gold Foil ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Resolution Limit ◽  
Transmission Electron ◽  
Crystal Lattice Defect ◽  
Void Effect ◽  
Lattice Resolution

A new specimen preparation technique for visualizing macromolecules by conventional transmission electron microscopy has been developed. In this technique the biopolymer-molecule is embedded in a thin monocrystalline gold foil. Such embedding can be performed in the following way: the biopolymer is deposited on an epitaxially-grown thin single-crystal gold film. The molecule is then occluded by further epitaxial growth. In such an epitaxial sandwich an occluded molecule is expected to behave as a crystal-lattice defect and give rise to contrast in the electron microscope.The resolution of the method should be limited only by the precision with which the epitaxially grown gold reflects the details of the molecular structure and, in favorable cases, can approach the lattice resolution limit.In order to estimate the strength of the contrast due to the void-effect arising from occlusion of the DNA-molecule in a gold crystal some calculations were performed.

Nano-Folded Gold Electrocatalysts Enhance the Selectivity of Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kam Sang Kwok ◽  
Yuxuan Wang ◽  
Michael Cao ◽  
Hao Shen ◽  
Weinan Xu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Mass Transport ◽  
Gold Film ◽  
X Ray Diffraction ◽  
Thin Gold Film ◽  
Faradaic Efficiency ◽  
X Ray ◽  
Transmission Electron ◽  
Carbon Monoxide Formation ◽  
Catalytic Interfaces

<p>The local structure and geometry of catalytic interfaces can influence the selectivity of chemical reactions. Here, using a pre-strained polymer, we uniaxially compress a thin gold film to form a nano-folded catalyst. We observe two kinds of folds and can tune the ratio of loose to tight folds by varying the extent of pre-strain in the polymer. We characterize the nano-folded catalysts using x-ray diffraction, scanning, and transmission electron microscopy. We observe grain reorientation and coarsening in the nano-folded gold catalysts. Electroreduction of carbon dioxide with these nano-folded catalysts reveals an enhancement of Faradaic efficiency for carbon monoxide formation by a factor of about four. This result suggests that electrolyte mass transport limitations and an increase of the local pH in the tight folds of the catalyst outweigh the effects of alterations in grain characteristics. Together, our studies demonstrate that nano-folded geometries can significantly alter grain characteristics, mass transport, and catalytic selectivity. </p>

scholarly journals Surface Acoustic Wave Biosensor with Laser-Deposited Gold Layer Having Controlled Porosity

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 173
Author(s):  
Dana Miu ◽  
Izabela Constantinoiu ◽  
Valentina Dinca ◽  
Cristian Viespe
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Gold Film ◽  
Good Control ◽  
Gold Layer ◽  
Porous Gold ◽  
Deposition Parameters ◽  
Acoustic Wave Sensors ◽  
Controlled Porosity ◽  
Wave Sensors

Laser-deposited gold immobilization layers having different porosities were incorporated into love wave surface acoustic wave sensors (LW-SAWs). Variation of pulsed laser deposition parameters allows good control of the gold film morphology. Biosensors with various gold film porosities were tested using the biotin–avidin reaction. Control of the Au layer morphology is important since the biotin and avidin layer morphologies closely follow that of the gold. The response of the sensors to biotin/avidin, which is a good indicator of biosensor performance, is improved when the gold layer has increased porosity. Given the sizes of the proteins, the laser-deposited porous gold interfaces have optimal pore dimensions to ensure protein stability.

scholarly journals Laser Superficial Fusion of Gold Nanoparticles with PEEK Polymer for Cardiovascular Application

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 971
Author(s):  
Oktawian Bialas ◽  
Mateusz Lis ◽  
Anna Woźniak ◽  
Marcin Adamiak
Keyword(s):  
Particle Size ◽  
Laser Beam ◽  
Gold Particle ◽  
Laser Power ◽  
Biomedical Application ◽  
Parameters Optimization ◽  
Size Reduction ◽  
Particle Size Reduction ◽  
Nano Gold ◽  
Gold Particle Size

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.

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