scholarly journals Ultra-Fine Control of Silica Shell Thickness on Silver Nanoparticle-Assembled Structures

2021 ◽  
Vol 22 (21) ◽  
pp. 11983
Author(s):  
Eunil Hahm ◽  
Ahla Jo ◽  
Eun Ji Kang ◽  
Sungje Bock ◽  
Xuan-Hung Pham ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Silver Nanoparticle ◽  
Dielectric Layer ◽  
Silica Coating ◽  
Silica Shell ◽  
Metal Nanoparticle ◽  
Ag Nps ◽  
Field Effects ◽  
Surface Enhanced Raman ◽  
Fine Control

To study the distance-dependent electromagnetic field effects related to the enhancement and quenching mechanism of surface-enhanced Raman scattering (SERS) or fluorescence, it is essential to precisely control the distance from the surface of the metal nanoparticle (NP) to the target molecule by using a dielectric layer (e.g., SiO2, TiO2, and Al2O3). However, precisely controlling the thickness of this dielectric layer is challenging. Herein, we present a facile approach to control the thickness of the silica shell on silver nanoparticle-assembled silica nanocomposites, SiO2@Ag NPs, by controlling the number of reacting SiO2@Ag NPs and the silica precursor. Uniform silica shells with thicknesses in the range 5–40 nm were successfully fabricated. The proposed method for creating a homogeneous, precise, and fine silica coating on nanocomposites can potentially contribute to a comprehensive understanding of the distance-dependent electromagnetic field effects and optical properties of metal NPs.

scholarly journals Tuning Localized Surface Plasmon Resonance of Nanoporous Gold with a Silica Shell for Surface Enhanced Raman Scattering

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 251 ◽  
Author(s):  
Wei Li ◽  
Chao Ma ◽  
Ling Zhang ◽  
Bin Chen ◽  
Luyang Chen ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Localized Surface Plasmon Resonance ◽  
Silica Coating ◽  
Silica Shell ◽  
Nanoporous Gold ◽  
Localized Surface Plasmon ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

We report the tuning of localized surface plasmon resonance (LSPR) of nanoporous gold (NPG) by silica coating, which also affects the surface enhanced Raman scattering (SERS) of NPG. In this study, controllable silica shell is assembled on the NPG surface, and a fully silica thin layer causes more than 50 nm red-shift of LSPR band due to dielectric medium dependence. Additionally, ~1 nm silica coated NPG film shows excellent SERS enhancement, which is due to electromagnetic coupling between ligaments and local surface plasmon field enhancement within pores, and theoretical analysis indicates that silica coating further improves the coupling effect, which demonstrates the electromagnetic origin of the tuning of SERS effect.

scholarly journals Facilely Flexible Imprinted Hemispherical Cavity Array for Effective Plasmonic Coupling as SERS Substrate

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3196
Author(s):  
Jihua Xu ◽  
Jinmeng Li ◽  
Guangxu Guo ◽  
Xiaofei Zhao ◽  
Zhen Li ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Mechanical Stability ◽  
Coupling Effect ◽  
Low Cost ◽  
Flexible Substrate ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Ag Nps ◽  
Surface Enhanced Raman ◽  
Sers Detection

The focusing field effect excited by the cavity mode has a positive coupling effect with the metal localized surface plasmon resonance (LSPR) effect, which can stimulate a stronger local electromagnetic field. Therefore, we combined the self-organizing process for component and array manufacturing with imprinting technology to construct a cheap and reproducible flexible polyvinyl alcohol (PVA) nanocavity array decorating with the silver nanoparticles (Ag NPs). The distribution of the local electromagnetic field was simulated theoretically, and the surface-enhanced Raman scattering (SERS) performance of the substrate was evaluated experimentally. The substrate shows excellent mechanical stability in bending experiments. It was proved theoretically and experimentally that the substrate still provides a stable signal when the excited light is incident from different angles. This flexible substrate can achieve low-cost, highly sensitive, uniform and conducive SERS detection, especially in situ detection, which shows a promising application prospect in food safety and biomedicine.

scholarly journals Recycling silver nanoparticle debris from laser ablation of silver nanowire in liquid media toward minimum material waste

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
June Sik Hwang ◽  
Jong-Eun Park ◽  
Gun Woo Kim ◽  
Hyeono Nam ◽  
Sangseok Yu ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Silver Nanoparticle ◽  
Building Materials ◽  
Raw Materials ◽  
Silver Nanowires ◽  
Silver Nanowire ◽  
Liquid Media ◽  
Ag Nps ◽  
Laser Patterning ◽  
Inexpensive Procedure

AbstractAs silver nanowires (Ag NWs) are usually manufactured by chemical synthesis, a patterning process is needed to use them as functional devices. Pulsed laser ablation is a promising Ag NW patterning process because it is a simple and inexpensive procedure. However, this process has a disadvantage in that target materials are wasted owing to the subtractive nature of the process involving the removal of unnecessary materials, and large quantities of raw materials are required. In this study, we report a minimum-waste laser patterning process utilizing silver nanoparticle (Ag NP) debris obtained through laser ablation of Ag NWs in liquid media. Since the generated Ag NPs can be used for several applications, wastage of Ag NWs, which is inevitable in conventional laser patterning processes, is dramatically reduced. In addition, electrophoretic deposition of the recycled Ag NPs onto non-ablated Ag NWs allows easy fabrication of junction-enhanced Ag NWs from the deposited Ag NPs. The unique advantage of this method lies in using recycled Ag NPs as building materials, eliminating the additional cost of junction welding Ag NWs. These fabricated Ag NW substrates could be utilized as transparent heaters and stretchable TCEs, thereby validating the effectiveness of the proposed process.

The small silver nanoparticle-assisted homogeneous sensing of thiocyanate ions with an ultra-wide window based on surface-enhanced Raman-extinction spectroscopy

2021 ◽  
Author(s):  
Xiang-Ru Bai ◽  
Lei Zhang ◽  
Jia-Qiang Ren ◽  
Ai-Guo Shen ◽  
Ji-Ming Hu
Keyword(s):  
Silver Nanoparticle ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Detection Window ◽  
First Time

For the first time, we present an original sensing strategy with an ultra-wide detection window from 17 nM to 20 mM to detect SCN− ions.

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