High-index Facets and Multidimensional Hotspots in Au-Decorated 24-faceted PbS for Ultrasensitive and Recyclable SERS Substrates

2021 ◽  
Author(s):  
Hao-Seng Kang ◽  
Ming-Yang Long ◽  
Jing-Chuang Liu ◽  
Yi-Tong Duan ◽  
Liang Ma ◽  
...  
Keyword(s):  
Charge Transfer ◽  
High Index ◽  
Sers Substrates ◽  
Electromagnetic Enhancement

The rational manipulation of morphology and architecture of the plasmonic metal/semiconductor hybrids is quite important to improve their SERS performance by optimizing the electromagnetic enhancement and charge transfer. Herein, PbS-Au...

Hybrid Substrates for Real-Time SERS-Based Chemical Sensors

1995 ◽  
Vol 49 (2) ◽  
pp. 193-199 ◽  
Author(s):  
E. A. Wachter ◽  
J. M. E. Storey ◽  
S. L. Sharp ◽  
K. T. Carron ◽  
Y. Jiang
Keyword(s):  
Protective Coatings ◽  
Protective Layer ◽  
Thin Metal Film ◽  
Sers Substrates ◽  
New Class ◽  
Electromagnetic Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Hybrid Substrates ◽  
Enhanced Raman Scattering

Since the discovery of the surface-enhanced Raman scattering (SERS) effect, numerous substrate designs have been proposed for a variety of analytical applications. Although many of these have offered exceptional electromagnetic enhancement, the durability and reusability of substrates have not always been acceptable for routine analytical use. This paper discusses the design and testing of a new class of hybrid SERS substrates specifically designed to optimize electromagnetic enhancement while also affording exceptional ruggedness and reversibility of response under challenging conditions. Substrate templates are fabricated lithographically into a quartz surface, then a thin metal film is deposited, and finally the entire surface is coated with a protective layer. Examples of inorganic and organic protective coatings are provided. Analytes are measured in flowing streams of airborne vapor and aqueous liquid. Properly designed surface coatings serve a dual role as both a protective layer and as a rapidly reversible selective adsorbent for specific analytes.

scholarly journals Ag–ZnO Nanocomposites Are Used for SERS Substrates and Promote the Coupling Reaction of PATP

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 922
Author(s):  
Liping Ma ◽  
Qijia Zhang ◽  
Jia Li ◽  
Xuemei Lu ◽  
Ce Gao ◽  
...  
Keyword(s):  
Chemical Reduction ◽  
Coupling Reaction ◽  
Semiconductor Materials ◽  
Sers Substrates ◽  
Electromagnetic Enhancement ◽  
Chemical Enhancement ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Semiconductor Nanocomposites ◽  
The Individual

Noble metal-semiconductor nanocomposites have received extensive attention in Surface Enhanced Raman Scattering (SERS) due to their unique properties. In this paper, the Ag–ZnO nanocomposites are prepared by hydrothermal growth and simple chemical reduction immersion. The synthesized nanocomposite material simultaneously integrates the individual enhancement effects of the two materials in the SERS, such as the electromagnetic enhancement of silver nanoparticles and the chemical enhancement of ZnO semiconductor materials. Using this substrate, Rhodamine 6G molecules with a concentration as low as 10−8 M can be detected, and the coupling reaction of PATP can be effectively promoted. The nanocomposite materials prepared by selecting appropriate semiconductor materials and metal materials combined, could be potentially applied, as SERS substrates, in certain catalytic reactions.

scholarly journals Plasmon-coupled Charge Transfer in FSZA Core-shell Microspheres with High SERS Activity and Pesticide Detection

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Donglai Han ◽  
Jiacheng Yao ◽  
Yingnan Quan ◽  
Ming Gao ◽  
Jinghai Yang
Keyword(s):  
Magnetic Field ◽  
Charge Transfer ◽  
Core Shell ◽  
Sers Substrate ◽  
Practical Application ◽  
Actual Application ◽  
Electromagnetic Enhancement ◽  
Sers Detection ◽  
Magnetite Particles ◽  
The Stability

Abstract A commercial SERS substrate does not only require strong enhancement, but also can be reused and recycled in actual application. Herein, Fe3O4/SiO2/ZnO/Ag (FSZA) have been synthesised, which consisted of Fe3O4 core with strong magnetic field response and an intermediate SiO2 layer as an electronic barrier to keep the stability of magnetite particles and outer ZnO and Ag as the effective layers for detecting pollutants. The SERS enhancement factor (EF) of the FSZA was ~8.2 × 105. The enhancement mechanism of the FSZA core-shell microspheres were anatomized. The electromagnetic enhancement of surface deposited Ag, charge transfer, and molecular and exciton resonances act together to cause such high enhancement factors. For practical application, the FSZA core-shell microspheres were also used to detect thiram, moreover, which was collected and separated by an external magnetic field, and maintained the SERS activity without significant decline during multiple tests. So the good enhancement performance and magnetic recyclability make the FSZA core-shell microspheres a promising candidates for practical SERS detection applications.

scholarly journals Preparation of ZnO nanoflowers for surface enhance Raman scattering applications

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Tuyen Nguyen Viet
Keyword(s):  
Raman Scattering ◽  
Self Assembly ◽  
Noble Metals ◽  
Zno Nanorods ◽  
Raman Signal ◽  
Sers Substrate ◽  
Chemical Substances ◽  
Sers Substrates ◽  
Electromagnetic Enhancement ◽  
Surface Enhanced Raman

Thanks to unique Raman spectra of chemical substances, a growing number of applications in environmental and biomedical fields based on Raman scattering has been developed. However, the low probability of Raman scattering hindered its potential development and thus, many different techniques were developed to enhance Raman signal. A key step of surface-enhanced Raman scattering technique is to prepare active SERS substrate from noble metals. The main enhancement mechanism is electromagnetic enhancement resulted from surface plasmon resonance. The disadvantages of nanoparticles based SERS substrates include high randomness due to self - assembly process of nanoparticles. Recently, a new kind of SERS substrates with order nanostructures of semiconductors combining with noble metals can serve as active SERS substrates, which are expected to possess high enhancement of Raman signals. In this study, ordered ZnO nanorods were first prepared by galvanic hydrothermal method and gold was sputtered on the as prepared ZnO nanomaterials to enhance Raman. Our SERS substrates exhibit promising high enhancement factors, and can detect chemical substances at concentration in nano molar range.

scholarly journals Charge-Transfer Resonance and Electromagnetic Enhancement Synergistically Enabling MXenes with Excellent SERS Sensitivity for SARS-CoV-2 S Protein Detection

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yusi Peng ◽  
Chenglong Lin ◽  
Li Long ◽  
Tanemura Masaki ◽  
Mao Tang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Protein Detection ◽  
Resonance Excitation ◽  
Excitation Wavelength ◽  
Potential Candidate ◽  
Practical Applications ◽  
Electromagnetic Enhancement ◽  
Resonance Enhancement ◽  
Sers Detection ◽  
Novel Coronavirus

AbstractThe outbreak of coronavirus disease 2019 has seriously threatened human health. Rapidly and sensitively detecting SARS-CoV-2 viruses can help control the spread of viruses. However, it is an arduous challenge to apply semiconductor-based substrates for virus SERS detection due to their poor sensitivity. Therefore, it is worthwhile to search novel semiconductor-based substrates with excellent SERS sensitivity. Herein we report, for the first time, Nb2C and Ta2C MXenes exhibit a remarkable SERS enhancement, which is synergistically enabled by the charge transfer resonance enhancement and electromagnetic enhancement. Their SERS sensitivity is optimized to 3.0 × 106 and 1.4 × 106 under the optimal resonance excitation wavelength of 532 nm. Additionally, remarkable SERS sensitivity endows Ta2C MXenes with capability to sensitively detect and accurately identify the SARS-CoV-2 spike protein. Moreover, its detection limit is as low as 5 × 10−9 M, which is beneficial to achieve real-time monitoring and early warning of novel coronavirus. This research not only provides helpful theoretical guidance for exploring other novel SERS-active semiconductor-based materials but also provides a potential candidate for the practical applications of SERS technology.

Study of charge transfer in FeTi

1983 ◽  
Vol 41 ◽  
pp. 296-297
Author(s):  
J. Taft∅
Keyword(s):  
Charge Transfer ◽  
Charge Distribution ◽  
Electron Scattering ◽  
Periodic System ◽  
Electron Distribution ◽  
Scattering Amplitude ◽  
Transition Elements ◽  
Hartree Fock ◽  
Cscl Structure ◽  
The Right

It is well known that for reflections corresponding to large interplanar spacings (i.e., sin θ/λ small), the electron scattering amplitude, f, is sensitive to the ionicity and to the charge distribution around the atoms. We have used this in order to obtain information about the charge distribution in FeTi, which is a candidate for storage of hydrogen. Our goal is to study the changes in electron distribution in the presence of hydrogen, and also the ionicity of hydrogen in metals, but so far our study has been limited to pure FeTi. FeTi has the CsCl structure and thus Fe and Ti scatter with a phase difference of π into the 100-ref lections. Because Fe (Z = 26) is higher in the periodic system than Ti (Z = 22), an immediate “guess” would be that Fe has a larger scattering amplitude than Ti. However, relativistic Hartree-Fock calculations show that the opposite is the case for the 100-reflection. An explanation for this may be sought in the stronger localization of the d-electrons of the first row transition elements when moving to the right in the periodic table. The tabulated difference between fTi (100) and ffe (100) is small, however, and based on the values of the scattering amplitude for isolated atoms, the kinematical intensity of the 100-reflection is only 5.10-4 of the intensity of the 200-reflection.

The usefulness of high index low symmetry zone axes for holz line analysis

1987 ◽  
Vol 45 ◽  
pp. 384-385
Author(s):  
C. M. Sung ◽  
D. B. Williams
Keyword(s):  
Lattice Parameter ◽  
High Order ◽  
Zone Axis ◽  
High Index ◽  
High Symmetry ◽  
Second Phases ◽  
Line Patterns ◽  
Low Symmetry ◽  
Line Analysis

Researchers have tended to use high symmetry zone axes (e.g. <111> <114>) for High Order Laue Zone (HOLZ) line analysis since Jones et al reported the origin of HOLZ lines and described some of their applications. But it is not always easy to find HOLZ lines from a specific high symmetry zone axis during microscope operation, especially from second phases on a scale of tens of nanometers. Therefore it would be very convenient if we can use HOLZ lines from low symmetry zone axes and simulate these patterns in order to measure lattice parameter changes through HOLZ line shifts. HOLZ patterns of high index low symmetry zone axes are shown in Fig. 1, which were obtained from pure Al at -186°C using a double tilt cooling holder. Their corresponding simulated HOLZ line patterns are shown along with ten other low symmetry orientations in Fig. 2. The simulations were based upon kinematical diffraction conditions.

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