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.

The controlled synthesis of plasmonic nanoparticle clusters as efficient surface-enhanced Raman scattering platforms

2015 ◽  
Vol 51 (42) ◽  
pp. 8793-8796 ◽  
Author(s):  
Seunghoon Lee ◽  
Jong Wook Hong ◽  
Su-Un Lee ◽  
Young Wook Lee ◽  
Sang Woo Han
Keyword(s):  
Ag Nanoparticles ◽  
Au Nanoparticle ◽  
Galvanic Replacement ◽  
Controlled Synthesis ◽  
Plasmonic Nanoparticle ◽  
Surface Enhanced ◽  
Nanoparticle Clusters ◽  
Surface Enhanced Raman ◽  
Fine Control ◽  
Enhanced Raman Scattering

Au nanoparticle clusters were prepared by fine control over the galvanic replacement of Ag nanoparticles with Au precursors.

scholarly journals Print metallic nanoparticles on a fiber probe for 1064-nm surface-enhanced Raman scattering

2019 ◽  
Vol 44 (20) ◽  
pp. 4997 ◽  
Author(s):  
Ana Sánchez-Solís ◽  
Farzia Karim ◽  
Md Shah Alam ◽  
Qiwen Zhan ◽  
Tzarara López-Luke ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Metallic Nanoparticles ◽  
Surface Enhanced Raman Scattering ◽  
Fiber Probe ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

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.

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