scholarly journals Photochemical Synthesis of Silver Nanodecahedrons under Blue LED Irradiation and Their SERS Activity

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 292 ◽  
Author(s):  
Mai Ngoc Tuan Anh ◽  
Dinh Tien Dung Nguyen ◽  
Ngo Vo Ke Thanh ◽  
Nguyen Thi Phuong Phong ◽  
Dai Hai Nguyen ◽  
...  
Keyword(s):  
Photochemical Synthesis ◽  
Characterization Methods ◽  
Light Emitting ◽  
Electromagnetic Enhancement ◽  
Transmission Electron ◽  
Photochemical Method ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Led Irradiation

Silver nanodecahedrons were successfully synthesized by a photochemical method under irradiation of blue light-emitting diodes (LEDs). The formation of silver nanodecahedrons at different LED irradiation times (0–72 h) was thoroughly investigated by employing different characterization methods such as ultraviolet–visible spectroscopy (UV–Vis), transmission electron microscopy (TEM), and Raman spectroscopy. The results showed that silver nanodecahedrons (AgNDs) were formed from silver nanoseeds after 6 h of LED irradiation. The surface-enhanced Raman scattering (SERS) effects of the synthesized AgNDs were also studied in comparison with those of spherical silver nanoparticles in the detection of 4-mercapto benzoic acid. Silver nanodecahedrons with a size of 48 nm formed after 48 h of LED irradiation displayed stronger SERS properties than spherical nanoparticles because of electromagnetic enhancement. The formation mechanism of silver nanodecahedrons is also reported in our study. The results showed that multihedral silver nanoseeds favored the formation of silver nanodecahedrons.

scholarly journals Nanoporous Ag-Au Bimetallic Triangular Nanoprisms Synthesized by Galvanic Replacement for Plasmonic Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hongmei Qian ◽  
Shoaib Anwer ◽  
G. Bharath ◽  
Shahid Iqbal ◽  
Lijuan Chen
Keyword(s):  
Metallic Nanoparticles ◽  
Galvanic Replacement ◽  
Transmission Electron ◽  
Surface Plasmon Coupling ◽  
Surface Enhanced ◽  
Particle Aggregates ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Good Biocompatibility ◽  
Elementary Mapping

Galvanic replacement is a versatile method of converting simple noble metallic nanoparticles into structurally more complex porous multimetallic nanostructures. In this work, roughened nanoporous Ag-Au bimetallic triangular nanoprisms (TNPs) are synthesized by galvanic replacement between smooth Ag triangular plates and AuCl4− ions. Transmission electron microscope and the elementary mapping measurements show that numerous protrusions and pores are formed on the {111} facets, and Ag and Au atoms are homogeneously distributed on the triangular plates. Due to the additional “hot spots” generated by the surface plasmon coupling of the newly formed protrusions and pores, the roughened nanoporous Ag-Au TNP aggregates demonstrate a higher surface-enhanced Raman scattering enhancement factor (seven times larger) and better reproducibility than that of smooth Ag triangular particle aggregates. These synthesized roughened nanoporous Ag-Au bimetallic TNPs are a promising candidate for the applications in analytical chemistry, biological diagnostics, and photothermal therapy due to their excellent plasmonic performances and good biocompatibility.

scholarly journals Tuning the Optical Properties of Large Gold Nanoparticle Arrays

2001 ◽  
Vol 676 ◽  
Author(s):  
Beomseok Kim ◽  
Steven L. Tripp ◽  
Alexander Wei
Keyword(s):  
Near Infrared ◽  
High Surface ◽  
Experimental Investigations ◽  
Transmission Electron ◽  
Surface Enhanced ◽  
Air Water Interface ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Infrared Wavelengths ◽  
Aggregate Structures

ABSTRACTGold nanoparticles in the mid-nanometer size regime can undergo self-organization into densely packed monoparticulate films at the air-water interface under appropriate passivation conditions. Films could be transferred onto hydrophilic Formvar-coated Cu grids by horizontal (Langmuir-Schaefer) deposition or by vertical retraction of immersed substrates. The latter method produced monoparticulate films with variable extinction and reflectance properties. Transmission electron microscopy revealed hexagonally close-packed arrays on the micron length scale. The extinction bands of these arrays shifted by hundreds of nanometers to near-infrared wavelengths and broadened enormously with increasing periodicity. Large particle arrays also demonstrated extremely high surface-enhanced Raman scattering (SERS), with enhancement factors greater than 107. Signal enhancements could be correlated with increasing periodicity and are in accord with earlier theoretical and experimental investigations involving nanoparticle aggregate structures.

Gold/Palladium and Silver/Palladium Colloids as Novel Metallic Substrates for Surface-Enhanced Raman Scattering

2005 ◽  
Vol 59 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Barbara Pergolese ◽  
Adriano Bigotto ◽  
Maurizio Muniz-Miranda ◽  
Giuseppe Sbrana
Keyword(s):  
Raman Scattering ◽  
Surface Enhanced Raman Scattering ◽  
Colloidal Nanoparticles ◽  
Visible Absorption ◽  
Transmission Electron ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Silver Palladium ◽  
Silver Colloidal Nanoparticles

New surface-enhanced Raman scattering (SERS) substrates, composed of gold or silver colloidal nanoparticles doped with palladium, were prepared. These novel colloids are stable and maintain a satisfactory SERS efficiency, even after long aging. The interest in doping the coinage metal nanoparticles with palladium is due to the well-known catalytic activity of this metal. Transmission electron microscopy (TEM) and ultraviolet–visible absorption spectroscopy were used to characterize the shape and size of the metal particles. It was found that these bimetallic colloidal nanoparticles have a core–shell structure, with gold or silver coated with palladium clusters.

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.

Near Field Optical Properties of Individual Ag Nanowire Dimers Encapsulated by Dielectric Layers

2011 ◽  
Vol 393-395 ◽  
pp. 193-196
Author(s):  
Song Lin Jin ◽  
Chao Ling Du ◽  
Da Ning Shi
Keyword(s):  
Optical Properties ◽  
Near Field ◽  
Peak Wavelength ◽  
Electromagnetic Enhancement ◽  
Dielectric Layers ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Two Parameters ◽  
Ag Nanowire

By finite element method (FEM), the near field optical properties of an individual Ag nanowire dimer encapsulated with nanometric dielectric layers were investigated. We demonstrated that the electromagnetic enhancement could be optimized by improving the substrates’ refractive index and the thickness, and gave the peak wavelength as a function of the two parameters separately. The results are important for further understanding surface-enhanced Raman Scattering (SERS) and have referential meaning for choosing the appropriate substrates in the application.

scholarly journals Facile In Situ Photochemical Synthesis of Silver Nanoaggregates for Surface-Enhanced Raman Scattering Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 685 ◽  
Author(s):  
Zhen Yin ◽  
Huilin He ◽  
Zhenming Wang ◽  
Xiaoguo Fang ◽  
Chunxiang Xu ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Microfluidic Channel ◽  
Surface Enhanced Raman Scattering ◽  
Photochemical Synthesis ◽  
Sers Substrate ◽  
Relative Standard ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Recently, photochemical synthesis has attracted wide interest on in situ preparing the surface-enhanced Raman scattering (SERS) substrate with excellent performance, especially in a compact space and microfluidic channel. Herein, a facile, green and cost-effective approach to in situ photochemically synthesize silver nanoaggregates is demonstrated for SERS applications. By adjusting the photo-irradiation conditions, the morphologies and sizes of the silver nanoaggregates can be deliberately tailored. The synthesized silver nanoaggregates-based substrates exhibit a highly sensitive and reproducible SERS activity with a low detection limit of 10−8 M for 4-Aminothiophenol detection and relative standard deviation of 12.3%, paving an efficient and promising route for in situ SERS-based rapid detection in the environmental monitoring and food quality control.

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