scholarly journals Synthesis of Monolayer Gold Nanorings Sandwich Film and Its Higher Surface-Enhanced Raman Scattering Intensity

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 519
Author(s):  
Liqiu Zhang ◽  
Tiying Zhu ◽  
Cheng Yang ◽  
Ho Young Jang ◽  
Hee-Jeong Jang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Hot Spots ◽  
High Performance ◽  
Fdtd Method ◽  
Surface Enhanced Raman Spectroscopy ◽  
Langmuir Blodgett ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Intensity

Most previous studies relating to surface-enhanced Raman spectroscopy (SERS) signal enhancement were focused on the interaction between the light and the substrate in the x-y axis. 3D SERS substrates reported in the most of previous papers could contribute partial SERS enhancement via z axis, but the increases of the surface area were the main target for those reports. However, the z axis is also useful in achieving improved SERS intensity. In this work, hot spots along the z axis were specifically created in a sandwich nanofilm. Sandwich nanofilms were prepared with self-assembly and Langmuir-Blodgett techniques, and comprised of monolayer Au nanorings sandwiched between bottom Ag mirror and top Ag cover films. Monolayer Au nanorings were formed by self-assembly at the interface of water and hexane, followed by Langmuir-Blodgett transfer to a substrate with sputtered Ag mirror film. Their hollow property allows the light transmitted through a cover film. The use of a Ag cover layer of tens nanometers in thickness was critical, which allowed light access to the middle Au nanorings and the bottom Ag mirror, resulting in more plasmonic resonance and coupling along perpendicular interfaces (z-axis). The as-designed sandwich nanofilms could achieve an overall ~8 times SERS signals amplification compared to only the Au nanorings layer, which was principally attributed to enhanced electromagnetic fields along the created z-axis. Theoretical simulations based on finite-difference time-domain (FDTD) method showed consistent results with the experimental ones. This study points out a new direction to enhance the SERS intensity by involving more hot spots in z-axis in a designer nanostructure for high-performance molecular recognition and detection.

scholarly journals Features and advantages of flexible silicon nanowires for SERS applications

2019 ◽  
Vol 10 ◽  
pp. 725-734
Author(s):  
Hrvoje Gebavi ◽  
Vlatko Gašparić ◽  
Dubravko Risović ◽  
Nikola Baran ◽  
Paweł Henryk Albrycht ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Self Assembly ◽  
Hot Spots ◽  
Surface Enhanced Raman Spectroscopy ◽  
The Novel ◽  
Sers Substrates ◽  
Metal Plating ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Optimal Intensity

The paper reports on the features and advantages of horizontally oriented flexible silicon nanowires (SiNWs) substrates for surface-enhanced Raman spectroscopy (SERS) applications. The novel SERS substrates are described in detail considering three main aspects. First, the key synthesis parameters for the flexible nanostructure SERS substrates were optimized. It is shown that fabrication temperature and metal-plating duration significantly influence the flexibility of the SiNWs and, consequently, determine the SERS enhancement. Second, it is demonstrated how the immersion in a liquid followed by drying results in the formation of SiNWs bundles influencing the surface morphology. The morphology changes were described by fractal dimension and lacunar analyses and correlated with the duration of Ag plating and SERS measurements. SERS examination showed the optimal intensity values for SiNWs thickness values of 60–100 nm. That is, when the flexibility of the self-assembly SiNWs allowed hot spots occurrence. Finally, the test with 4-mercaptophenylboronic acid showed excellent SERS performance of the flexible, horizontally oriented SiNWs in comparison with several other commercially available substrates.

scholarly journals Preparation of Fe3O4-Ag Nanocomposites with Silver Petals for SERS Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1288
Author(s):  
Thi Thuy Nguyen ◽  
Fayna Mammeri ◽  
Souad Ammar ◽  
Thi Bich Ngoc Nguyen ◽  
Trong Nghia Nguyen ◽  
...  
Keyword(s):  
Self Assembly ◽  
Hot Spots ◽  
Surface Enhanced Raman Spectroscopy ◽  
Electrical Field ◽  
Stabilizing Agents ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Sensing ◽  
Applied Electrical Field ◽  
Positively Charged

The formation of silver nanopetal-Fe3O4 poly-nanocrystals assemblies and the use of the resulting hetero-nanostructures as active substrates for Surface Enhanced Raman Spectroscopy (SERS) application are here reported. In practice, about 180 nm sized polyol-made Fe3O4 spheres, constituted by 10 nm sized crystals, were functionalized by (3-aminopropyl)triethoxysilane (APTES) to become positively charged, which can then electrostatically interact with negatively charged silver seeds. Silver petals were formed by seed-mediated growth in presence of Ag+ cations and self-assembly, using L-ascorbic acid (L-AA) and polyvinyl pyrrolidone (PVP) as mid-reducing and stabilizing agents, respectively. The resulting plasmonic structure provides a rough surface with plenty of hot spots able to locally enhance significantly any applied electrical field. Additionally, they exhibited a high enough saturation magnetization with Ms = 9.7 emu g−1 to be reversibly collected by an external magnetic field, which shortened the detection time. The plasmonic property makes the engineered Fe3O4-Ag architectures particularly valuable for magnetically assisted ultra-sensitive SERS sensing. This was unambiguously established through the successful detection, in water, of traces, (down to 10−10 M) of Rhodamine 6G (R6G), at room temperature.

scholarly journals Hydrophobic multiscale cavities for high-performance and self-cleaning surface-enhanced Raman spectroscopy (SERS) sensing

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaofei Zhao ◽  
Chundong Liu ◽  
Jing Yu ◽  
Zhen Li ◽  
Lu Liu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Performance ◽  
Light Trapping ◽  
Organic Pollutant ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrates ◽  
Highly Sensitive ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Self Cleaning

AbstractCavity array, with excellent optical capture capability, has received increasing attention for the surface-enhanced Raman spectroscopy (SERS)-active substrates. Here, we proposed molybdenum disulfide (MoS2) nanocavities growing on pyramid Si (PSi) composed of in situ reduced Au nanoparticles (AuNPs), which can form the multiscale cavities (MSCs), and is facile for the couple of the plasmon. We demonstrated that the PSi/MoS2/Au MSCs can serve as highly sensitive, uniform, and stable SERS substrates for rhodamine 6G (R6G), crystal violet, and adenosine triphosphate detection, benefiting from the synergistic effect of the enhanced light trapping and the effective plasmonic couple. The couple of the plasmon in the MSCs is evidently proved by finite-difference time domain simulation, showing the strong electromagnetic field is located around the cavity wall. Moreover, the excellent hydrophobicity of the PSi/MoS2/AuNPs substrate endows it with the ability for the directional monitoring of organic pollutant in a mixture of oil and water. Finally, we demonstrated the MSCs with outstanding photocatalytic performance could achieve the renewable utilization by self-cleaning, which was attributed to the fast electron transfer and effective light absorption. The proposed PSi/MoS2/AuNPs MSC represents a robust mean using the plasmonic metal/semiconductor heterostructure for high-performance SERS sensors and photodegradation.

Interfacial self-assembly of nanostructured silver octahedra for surface-enhanced Raman spectroscopy

2018 ◽  
Vol 11 (05) ◽  
pp. 1850028 ◽  
Author(s):  
Anna A. Semenova ◽  
Alexander E. Baranchikov ◽  
Vladimir K. Ivanov ◽  
Eugene A. Goodilin
Keyword(s):  
Raman Spectroscopy ◽  
Self Assembly ◽  
Hot Spots ◽  
Active Material ◽  
Surface Enhanced Raman Spectroscopy ◽  
Interfacial Region ◽  
Pickering Emulsions ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Scattering Signal

A novel robust and effective approach is suggested to form thin film substrates for surface-enhanced Raman spectroscopy (SERS) using interfacial self-assembly in demixing water/toluene Pickering emulsions collecting silver octahedral mesocages onto a finally flat interfacial region. The freely floating self-assembled silver films obtained after toluene evaporation can be transferred onto various substrates including those with an ordered superficial relief causing a further alignment of silver octahedra. A special porous aggregative structure of the octahedra mesocages provokes a great number of hot spots allowing a large amplification of Raman scattering signal of model dye analytes and molecular thiol products of crude oil desulfurization. The suggested method seems to be an easy scaling route for SERS active material production.

scholarly journals SERS Biosensor Based on Engineered 2D-Aperiodic Nanostructure for In-Situ Detection of Viable Brucella Bacterium in Complex Matrix

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 886
Author(s):  
Massimo Rippa ◽  
Riccardo Castagna ◽  
Domenico Sagnelli ◽  
Ambra Vestri ◽  
Giorgia Borriello ◽  
...  
Keyword(s):  
High Performance ◽  
Foodborne Pathogen ◽  
Surface Enhanced Raman Spectroscopy ◽  
High Performing ◽  
Sensing Platform ◽  
Food Detection ◽  
Raman Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
In Situ Detection

Brucella is a foodborne pathogen globally affecting both the economy and healthcare. Surface Enhanced Raman Spectroscopy (SERS) nano-biosensing can be a promising strategy for its detection. We combined high-performance quasi-crystal patterned nanocavities for Raman enhancement with the use of covalently immobilized Tbilisi bacteriophages as high-performing bio-receptors. We coupled our efficient SERS nano-biosensor to a Raman system to develop an on-field phage-based bio-sensing platform capable of monitoring the target bacteria. The developed biosensor allowed us to identify Brucella abortus in milk by our portable SERS device. Upon bacterial capture from samples (104 cells), a signal related to the pathogen recognition was observed, proving the concrete applicability of our system for on-site and in-food detection.

scholarly journals SERS on Bimetallic Nanostructured thin films

2021 ◽  
Author(s):  
revathy m s ◽  
D Murugesan ◽  
Naidu Dhanpal Jayram
Keyword(s):  
Thin Films ◽  
Thermal Evaporation ◽  
Low Cost ◽  
Active Surface ◽  
Surface Enhanced Raman Spectroscopy ◽  
Nanostructured Film ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
The Cost

Abstract Thin films and Surface Enhanced Raman spectroscopy have a strong bonding towards development of Sensors. From last 4 decades SERS has been used as effective tool for detection of toxic dyes, in food industry and agriculture world. To minimize the cost and fabrication over large surface is the most challenging task in substrate fabrication. In the present work an attempt has been made towards dual coatings, which could act as an effective SERS Substrates. An effective and facile approach of low cost bi-metallic Nanostructured film has been fabricated using thermal evaporation. Using the standard characterization techniques such as FE-SEM and XRD, the obtained films were Rhodamine 6G was used as an analyte for the SERS studies. The detection of R6G was up to 10− 10mol l− 1solution.The present bi-metallic coating can be serves as an excellent SERS active surface and provides a versatile pathway to fabricate anisotropic nanostructure on a glass film.

Self-assembly of ultrathin gold nanowires and single walled carbon nanotubes as a highly sensitive substrate for surface enhanced Raman spectroscopy

2016 ◽  
Vol 40 (9) ◽  
pp. 7286-7289 ◽  
Author(s):  
Yuanchao Zhang ◽  
Jingquan Liu ◽  
Da Li ◽  
Fuhua Yan ◽  
Xin Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Self Assembly ◽  
Single Walled Carbon Nanotubes ◽  
Surface Enhanced Raman Spectroscopy ◽  
Gold Nanowires ◽  
Highly Sensitive ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Walled Carbon Nanotubes

Self-assembly of ultrathin gold nanowires and single-walled carbon nanotubes as highly sensitive substrates for surface enhanced Raman spectroscopy.

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...

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