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.

Surface-enhanced Raman spectroscopy for DNA detection by the self-assembly of Ag nanoparticles onto Ag nanoparticle–graphene oxide nanocomposites

2015 ◽  
Vol 17 (28) ◽  
pp. 18443-18448 ◽  
Author(s):  
Tsung-Wu Lin ◽  
Hong-Yi Wu ◽  
Ting-Ti Tasi ◽  
Ying-Huang Lai ◽  
Hsin-Hui Shen
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
Ag Nanoparticles ◽  
Surface Enhanced Raman Spectroscopy ◽  
The Self ◽  
Sensing System ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Sers Sensing

A novel surface-enhanced Raman scattering (SERS) sensing system which operates by the self-assembly of Ag nanoparticles (AgNPs) onto the nanocomposite of AgNPs and graphene oxide (AgNP–GO) in the presence of two complementary DNAs has been developed.

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 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.

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...

scholarly journals SERS Sensing Properties of New Graphene/Gold Nanocomposite

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1236 ◽  
Author(s):  
Giulia Neri ◽  
Enza Fazio ◽  
Placido Giuseppe Mineo ◽  
Angela Scala ◽  
Anna Piperno
Keyword(s):  
Rhodamine 6G ◽  
Surface Enhanced Raman Spectroscopy ◽  
Molecular Probes ◽  
Au Nps ◽  
Nitrogen Doped ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Sers Sensing

The development of graphene (G) substrates without damage on the sp2 network allows to tune the interactions with plasmonic noble metal surfaces to finally enhance surface enhanced Raman spectroscopy (SERS) effect. Here, we describe a new graphene/gold nanocomposite obtained by loading gold nanoparticles (Au NPs), produced by pulsed laser ablation in liquids (PLAL), on a new nitrogen-doped graphene platform (G-NH2). The graphene platform was synthesized by direct delamination and chemical functionalization of graphite flakes with 4-methyl-2-p-nitrophenyl oxazolone, followed by reduction of p-nitrophenyl groups. Finally, the G-NH2/Au SERS platform was prepared by using the conventional aerography spraying technique. SERS properties of G-NH2/Au were tested using Rhodamine 6G (Rh6G) and Dopamine (DA) as molecular probes. Raman features of Rh6G and DA are still detectable for concentration values down to 1 × 10−5 M and 1 × 10−6 M respectively.

scholarly journals Porous carbon nanowire array for surface-enhanced Raman spectroscopy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nan Chen ◽  
Ting-Hui Xiao ◽  
Zhenyi Luo ◽  
Yasutaka Kitahama ◽  
Kotaro Hiramatsu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Porous Carbon ◽  
Hot Spots ◽  
Strong Dependence ◽  
Nanowire Array ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Abstract Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for vibrational spectroscopy as it provides several orders of magnitude higher sensitivity than inherently weak spontaneous Raman scattering by exciting localized surface plasmon resonance (LSPR) on metal substrates. However, SERS can be unreliable for biomedical use since it sacrifices reproducibility, uniformity, biocompatibility, and durability due to its strong dependence on “hot spots”, large photothermal heat generation, and easy oxidization. Here, we demonstrate the design, fabrication, and use of a metal-free (i.e., LSPR-free), topologically tailored nanostructure composed of porous carbon nanowires in an array as a SERS substrate to overcome all these problems. Specifically, it offers not only high signal enhancement (~106) due to its strong broadband charge-transfer resonance, but also extraordinarily high reproducibility due to the absence of hot spots, high durability due to no oxidization, and high compatibility to biomolecules due to its fluorescence quenching capability.

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