scholarly journals Template-assisted colloidal self-assembly of macroscopic magnetic metasurfaces

2016 ◽  
Vol 191 ◽  
pp. 159-176 ◽  
Author(s):  
Martin Mayer ◽  
Moritz Tebbe ◽  
Christian Kuttner ◽  
Max J. Schnepf ◽  
Tobias A. F. König ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Self Assembly ◽  
Rational Design ◽  
Gold Film ◽  
Visible Spectrum ◽  
Close Correlation ◽  
Metallic Film ◽  
The Road ◽  
Electromagnetic Simulations ◽  
Effective Magnetic Permeability

We demonstrate a template-assisted colloidal self-assembly approach for magnetic metasurfaces on macroscopic areas. The choice of anisotropic colloidal particle geometry, assembly pattern and metallic film is based on rational design criteria, taking advantage of mirror-charge effects for gold nanorods placed on gold film. Monodisperse gold nanorods prepared utilizing wet-chemistry are arranged with high precision on wrinkled templates to form linear array-type assemblies and subsequently transferred to a thin gold film. Due to the obtained particle-to-film distance of 1.1 nm, the plasmonic mode of the nanorod is able to couple efficiently with the supporting metallic film, giving rise to a magnetic mode in the visible spectrum (721 nm). Conventional UV-vis-NIR measurements in close correlation with electromagnetic simulations provide evidence for the presence of a magnetic resonance on the macroscopic area. The herein presented scalable lithography-free fabrication process paves the road towards colloidal functional metasurfaces with an optical response in the effective magnetic permeability.

Plasmonics tunable Ag-coated gold nanorods arrays as reusable SERS substrates for multiplexed antibiotics detection

2021 ◽  
Author(s):  
Xiaoya Peng ◽  
Dan Li ◽  
Yuanting Li ◽  
Haibo Xing ◽  
Wei Deng
Keyword(s):  
Gold Nanorods ◽  
Self Assembly ◽  
Aqueous Media ◽  
Antibiotic Residues ◽  
Sers Substrates ◽  
Antibiotics Detection ◽  
Robust Strategies

Antibiotic contaminants in aqueous media pose serious threat to human and ecological environments. Therefore, it is necessary to develop robust strategies to detect antibiotic residues. For this purpose, a self-assembly...

Examining the structure of the mature amyloid fibril

2002 ◽  
Vol 30 (4) ◽  
pp. 521-525 ◽  
Author(s):  
O. S. Makin ◽  
L. C. Serpell
Keyword(s):  
Self Assembly ◽  
Rational Design ◽  
Amyloid Fibrils ◽  
Structural Information ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cryo Electron Microscopy ◽  
Fibre Diffraction ◽  
Complementary Techniques ◽  
Mature Fibril

The pathogenesis of the group of diseases known collectively as the amyloidoses is characterized by the deposition of insoluble amyloid fibrils. These are straight, unbranching structures about 70–120 å (1 å = 0.1 nm) in diameter and of indeterminate length formed by the self-assembly of a diverse group of normally soluble proteins. Knowledge of the structure of these fibrils is necessary for the understanding of their abnormal assembly and deposition, possibly leading to the rational design of therapeutic agents for their prevention or disaggregation. Structural elucidation is impeded by fibril insolubility and inability to crystallize, thus preventing the use of X-ray crystallography and solution NMR. CD, Fourier-transform infrared spectroscopy and light scattering have been used in the study of the mechanism of fibril formation. This review concentrates on the structural information about the final, mature fibril and in particular the complementary techniques of cryo-electron microscopy, solid-state NMR and X-ray fibre diffraction.

Controlling directed self-assembly of gold nanorods in patterned PS-b-PMMA thin films

2015 ◽  
Vol 26 (5) ◽  
pp. 055301 ◽  
Author(s):  
Fengyuan Lai ◽  
Theodorian Borca-Tasciuc ◽  
Joel Plawsky
Keyword(s):  
Thin Films ◽  
Gold Nanorods ◽  
Self Assembly

scholarly journals Ag–Au Core–Shell Triangular Nanoprisms for Improving p-g-C3N4 Photocatalytic Hydrogen Production

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3347
Author(s):  
Yali Guo ◽  
Anzhou Xu ◽  
Juan Hou ◽  
Qingcui Liu ◽  
Hailong Li ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Self Assembly ◽  
Rational Design ◽  
Photogenerated Electron ◽  
Core Shell ◽  
Co Catalyst ◽  
Replacement Method ◽  
Assembly Method ◽  
Free Replacement ◽  
Electron Holes

Ag–Au core–shell triangular nanoprisms (Ag@Au TNPs) have aroused extensive research interest in the field of hydrogen evolution reaction (HER) due to their strong plasmon effect and stability. Here, Ag@Au TNPs were fabricated by the galvanic-free replacement method. Then, we loaded them on protonated g-C3N4 nanoprisms (P–CN) by the electrostatic self-assembly method as an efficient plasmonic photocatalyst for HER. The hydrogen production rate of Ag@Au TNPs/P–CN (4.52 mmol/g/h) is 4.1 times higher than that of P–CN (1.11 mmol/g/h) under simulated sunlight irradiation, making it the most competitive material for water splitting. The formed Schottky junction helps to trap the hot electrons generated from Ag@Au TNPs, and the well-preserved tips of the Ag@Au TNPs can effectively generate an electromagnetic field to inhibit the photogenerated electron–holes pairs recombination. This study suggests that the rational design of Ag@Au TNPs by the galvanic-free replacement method is an effective co-catalyst for HER and boosting the additional combination of plasmonic metals and catalyst metals for the enhancement to HER.

Lay Gold Nanorods Monolayer down on Solid Surfaces for Surface Enhanced Raman Spectroscopy Applications

2021 ◽  
Author(s):  
haidong Zhao ◽  
Katsuhiro Isozaki ◽  
Tomoya Taguchi ◽  
Shengchun Yang ◽  
Kazushi Miki
Keyword(s):  
Raman Spectroscopy ◽  
Gold Nanorods ◽  
Hybrid Method ◽  
Self Assembly ◽  
Surface Enhanced Raman Spectroscopy ◽  
Solid Substrate ◽  
Solvent Evaporation ◽  
Solid Surfaces ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Laying-down gold nanorods (GNRs) of a monolayer immobilized on a solid substrate was realized with the hybrid method, a combination of three elemental technologies: self-assembly, electrophoresis, and solvent evaporation. The...

ENERGETICALLY AND STERICALLY FAVORABLE ASSEMBLY OF IDENTICAL GOLD NANORODS WITH VARYING CONCENTRATIONS OF NANOSPHERES

2021 ◽  
pp. 2150028
Author(s):  
IMTIAZ AHMAD ◽  
AKHLAQ HUSSAIN ◽  
AMBREEN ALI ◽  
RAHIM JAN
Keyword(s):  
Gold Nanorods ◽  
Self Assembly ◽  
Gold Nanorod ◽  
Potential Well ◽  
Separation Effect ◽  
Face To Face ◽  
Inner Region

Gold nanorod ribbon-like arrays as well as shape-separation effect of rods from sphere-like nanoparticles have been evaluated for identical nanorod suspension with various concentration of nanospheres. These sphere-rod mixtures are prepared with help of different amounts of AgNO3. Deposits of nanoparticles at various positions of the coffee-stain ring are observed in different arrangements. For instance, face-to-face aligned nanorods get settled in ribbon-like superstructures and these arrays are observed to be self-separated from spheres. Self-assembly and shape-separation effect are observed more systematic at the outer-edges than the inner-region of the coffee-stain ring. Experimentally, it has been observed that face-to-face formation of nanorods in suspension is energetically more probable arrangement. As the separation between two nanorods increases, the depth of potential well decreases, indicating that the upper layers of nanorods are more under the influence of lower placed nanorods than those placed in the same plane. Energetically and sterically, more feasible arrangements are observed.

scholarly journals Pavement Crack Detection from Hyperspectral Images Using a Novel Asphalt Crack Index

2020 ◽  
Vol 12 (18) ◽  
pp. 3084 ◽  
Author(s):  
Mohamed Abdellatif ◽  
Harriet Peel ◽  
Anthony G. Cohn ◽  
Raul Fuentes
Keyword(s):  
Crack Detection ◽  
Early Stage ◽  
Visible Spectrum ◽  
Hyperspectral Data ◽  
Hyperspectral Images ◽  
Surface Material ◽  
Pavement Condition ◽  
The Road ◽  
Road Pavement ◽  
Crack Index

Detection of road pavement cracks is important and needed at an early stage to repair the road and extend its lifetime for maintaining city roads. Cracks are hard to detect from images taken with visible spectrum cameras due to noise and ambiguity with background textures besides the lack of distinct features in cracks. Hyperspectral images are sensitive to surface material changes and their potential for road crack detection is explored here. The key observation is that road cracks reveal the interior material that is different from the worn surface material. A novel asphalt crack index is introduced here as an additional clue that is sensitive to the spectra in the range 450–550 nm. The crack index is computed and found to be strongly correlated with the appearance of fresh asphalt cracks. The new index is then used to differentiate cracks from road surfaces. Several experiments have been made, which confirmed that the proposed index is effective for crack detection. The recall-precision analysis showed an increase in the associated F1-score by an average of 21.37% compared to the VIS2 metric in the literature (a metric used to classify pavement condition from hyperspectral data).

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