The Enhanced Raman Scattering from Ag Nanoball/ZnO Hollow Nanosphere Arrays Fabricated by Laser-Induced Annealing

2014 ◽  
Vol 609-610 ◽  
pp. 779-783
Author(s):  
Ya Shu Zang ◽  
Jun Yin ◽  
Jing Li ◽  
Jun Yong Kang

In this work, a facile method was presented to produce Ag nanoball (NB)/ZnO hollow nanosphere (HNS) hybrid structure. Large scale, two-dimensional (2D) ZnO HNS arrays were fabricated on sapphire substrates using the polystyrene (PS) nanospheres as the template. Ag film were deposited on ZnO HNS arrays by radio frequency (RF) magnetron sputtering and then aggregated into Ag NBs on the top of ZnO HNS by the laser irradiation treatment. The size and distribution of Ag NB arrays were controlled by employing different ZnO HNS supporting structure templates. The scanning electron microscopy (SEM) was applied to visually study the evolution process of Ag NB/ZnO NHS arrays. X-ray diffraction (XRD) was carried out to characterize crystal structures of the samples. Obvious surface enhanced Raman (SERS) signals were observed from the Ag NB/ZnO NHS nanocomposite structure compared with that in the ZnO HNS structure by using the R6G as the testing agent. Theoretical simulation results demonstrate that the Raman enhancement originates from the significant enhanced local electromagnetic field induced by the surface plasmon resonance (SPR) of Ag NBs.

2014 ◽  
Vol 16 (48) ◽  
pp. 26983-26990 ◽  
Author(s):  
Joel Ming Rui Tan ◽  
Justina Jiexin Ruan ◽  
Hiang Kwee Lee ◽  
In Yee Phang ◽  
Xing Yi Ling

A high-throughput fabrication of a stable and uniform superhydrophobic SERS platform is demonstrated. It is able to detect trace molecules at ultra-low detection limit of 10−17 M (10 aM) using just 4 μL of analyte solutions.


Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 520 ◽  
Author(s):  
Jia Zhu ◽  
Guanzhou Lin ◽  
Meizhang Wu ◽  
Zhuojie Chen ◽  
Peimin Lu ◽  
...  

Technology transfer from laboratory into practical application needs to meet the demands of economic viability and operational simplicity. This paper reports a simple and convenient strategy to fabricate large-scale and ultrasensitive surface-enhanced Raman scattering (SERS) substrates. In this strategy, no toxic chemicals or sophisticated instruments are required to fabricate the SERS substrates. On one hand, Ag nanoparticles (NPs) with relatively uniform size were synthesized using the modified Tollens method, which employs an ultra-low concentration of Ag+ and excessive amounts of glucose as a reducing agent. On the other hand, when a drop of the colloidal Ag NPs dries on a horizontal solid surface, the droplet becomes ropy, turns into a layered structure under gravity, and hardens. During evaporation, capillary flow was burdened by viscidity resistance from the ropy glucose solution. Thus, the coffee-ring effect is eliminated, leading to a uniform deposition of Ag NPs. With this method, flat Ag NPs-based SERS active films were formed in array-well plates defined by hole-shaped polydimethylsiloxane (PDMS) structures bonded on glass substrates, which were made for convenient detection. The strong SERS activity of these substrates allowed us to reach detection limits down to 10−14 M of Rhodamine 6 G and 10−10 M of thiram (pesticide).


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chao Zhang ◽  
Zhaoxiang Li ◽  
Si Qiu ◽  
Weixi Lu ◽  
Mingrui Shao ◽  
...  

Abstract Regulation of hot spots exhibits excellent potential in many applications including nanolasers, energy harvesting, sensing, and subwavelength imaging. Here, hat-shaped hierarchical nanostructures with different space curvatures have been proposed to enhance hot spots for facilitating surface-enhanced Raman scattering (SERS) and plasmon-driven catalysis applications. These novel nanostructures comprise two layers of metal nanoparticles separated by hat-shaped MoS2 films. The fabrication of this hybrid structure is based on the thermal annealing and thermal evaporation of self-assembled polystyrene spheres, which are convenient to control the metal particle size and the curvature of hat-shaped nanostructures. Based on the narrow gaps produced by the MoS2 films and the curvature of space, the constructed platform exhibits superior SERS capability and achieves ultrasensitive detection for toxic molecules. Furthermore, the surface catalytic conversion of p-nitrothiophenol (PNTP) to p, p′-dimercaptobenzene (DMAB) was in situ monitored by the SERS substrate. The mechanism governing this regulation of hot spots is also investigated via theoretical simulations.


2017 ◽  
Vol 205 ◽  
pp. 121-148 ◽  
Author(s):  
P. Dawson ◽  
D. Frey ◽  
V. Kalathingal ◽  
R. Mehfuz ◽  
J. Mitra

Quantitative understanding of the electromagnetic component in enhanced Raman spectroscopy is often difficult to achieve on account of the complex substrate structures utilised. We therefore turn to two structurally simple systems amenable to detailed modelling. The first is tip-enhanced Raman scattering under electron scanning tunnelling microscopy control (STM-TERS) where, appealing to understanding developed in the context of photon emission from STM, it is argued that the localised surface plasmon modes driving the Raman enhancement exist in the visible and near-infrared regime only by virtue of significant modification to the optical properties of the tip and sample metals (gold here). This is due to the strong dc field-induced (∼109V m−1) non-linear corrections to the dielectric function of goldviathe third order susceptibility term in the polarisation. Also, sub-5 nm spatial resolution is shown in the modelling. Secondly, we suggest a novel deployment of hybrid plasmonic waveguide modes in surface enhanced Raman scattering (HPWG-SERS). This delivers strong confinement of electromagnetic energy in a ∼10 nm oxide ‘gap’ between a high-index dielectric material of nanoscale width (a GaAs nanorod and a 100 nm Si slab are considered here) and a metal, yielding a monotonic variation in the Raman enhancement factor as a function of wavelength with no long-wavelength cut-off, both features that contrast with STM-TERS.


2015 ◽  
Vol 17 (33) ◽  
pp. 21343-21347 ◽  
Author(s):  
Yan Guo ◽  
Leilei Kang ◽  
Shaona Chen ◽  
Xin Li

Driven by the ultrasensitivity of the surface-enhanced Raman scattering (SERS) technique and the directive selection of molecular imprinting polymers (MIPs), core–shell silver-molecularly imprinted polymer (Ag@MIP) hybrid structure was synthesized to serve as a novel SERS platform.


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