Bimetallic gold core–silver shell nanorod performance for surface enhanced Raman spectroscopy

Nima, Zeid A.; Davletshin, Yevgeniy R.; Watanabe, Fumiya; Alghazali, Karrar M.; Kumaradas, J. Carl; Biris, Alexandru S.

doi:10.1039/c7ra06573f

Cited by 20 publications

(25 citation statements)

References 51 publications

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“…Therefore, most commercial SERS products are based on Au nanostructures (e.g., gold nanopillars and gold nanopatterns). Recently, Au@Ag core–shell NPs and Au/Ag alloy nanocomposites were proposed to realize better performance in SERS applications with improved stability . In this work, we report a three‐layered metamaterial superabsorber structure with hybrid random Au and Ag NPs as the top layer.…”

Section: Introductionmentioning

confidence: 96%

“…Recently, Au@Ag core-shell NPs and Au/Ag alloy nanocomposites were proposed to realize better performance in SERS applications with improved stability. [20,21] In this work, we report a three-layered metamaterial superabsorber structure with hybrid random Au and Ag NPs as the top layer. By immobilizing smaller Au NPs between larger Ag NPs, the gap between metallic NPs can be reduced significantly.…”

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confidence: 99%

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Superabsorbing Metasurfaces with Hybrid Ag–Au Nanostructures for Surface‐Enhanced Raman Spectroscopy Sensing of Drugs and Chemicals

Gao

Zhang

et al. 2018

Small Methods

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Reliability, shelf time, and uniformity are major challenges for most metallic nanostructures for surface‐enhanced Raman spectroscopy (SERS). Due to the randomness of the localized field supported by silver and gold nanopatterns in conventional structures, the quantitative analysis of the target in the practical application of SERS sensing is a challenge. Here, a superabsorbing metasurface with hybrid Ag–Au nanostructures is proposed. A two‐step process of deposition plus subsequent thermal annealing is developed to shrink the gap among the metallic nanoparticles with no top‐down lithography technology involved. Because of the light trapping strategy enabled by the hybrid Ag–Au metasurface structure, the excitation laser energy can be localized at the edges of the nanoparticles more efficiently, resulting in enhanced sensing resolution. Intriguingly, because more hot spots are excited over a given area with higher density of small nanoparticles, the spatial distribution of the localized field is more uniform, resulting in superior performance for potential quantitative sensing of drugs (i.e., cocaine) and chemicals (i.e., molecules with thiol groups in this report). Furthermore, the final coating of the second Au nanoparticle layer improves the reliability of the chip, which is demonstrated effective after 12 month shelf time in an ambient storage environment.

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Section: Introductionmentioning

confidence: 96%

mentioning

confidence: 99%

Superabsorbing Metasurfaces with Hybrid Ag–Au Nanostructures for Surface‐Enhanced Raman Spectroscopy Sensing of Drugs and Chemicals

Gao

Zhang

et al. 2018

Small Methods

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“…The effect on the SERS intensity for a p ‐aminothiophenol self‐assembled gold nanorod substrate, without and with a silver shell with thicknesses varying between 1 and 4 nm, is shown in Figure b (corresponding transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) images are shown in Figure a). Compared to bare gold nanorods, those covered with a silver shell showed increased Raman intensity, with different spectral behavior displayed with varying silver thickness . The use of a thin film composed of nickel–silver core–shell nanoparticles embedded in alumina matrix has also been reported …”

Section: Nanomaterials For Sensingmentioning

confidence: 99%

“…i) Comparison of the SERS data measured for 4‐MPy (50 µL in 50 × 10 −3 m ethanol) deposited on substrate made from Au–Pt/Ag nanostructures with the normal Raman spectrum obtained for pure‐4‐MPy deposited on a glass slide; excitation wavelength: 633 nm. a,b) Reproduced with permission . Copyright 2017, Royal Society of Chemistry.…”

Section: Nanomaterials For Sensingmentioning

confidence: 99%

Recent Advances in 2D Inorganic Nanomaterials for SERS Sensing

et al. 2019

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Surface‐enhanced Raman spectroscopy is a powerful and sensitive analytical tool that has found application in chemical and biomolecule analysis and environmental monitoring. Since its discovery in the early 1970s, a variety of materials ranging from noble metals to nanostructured materials have been employed as surface enhanced Raman scattering (SERS) substrates. In recent years, 2D inorganic materials have found wide use in the development of SERS‐based chemical sensors owing to their unique thickness dependent physico‐chemical properties with enhanced chemical‐based charge‐transfer processes. Here, recent advances in the application of various 2D inorganic nanomaterials, including graphene, boron nitride, semiconducting metal oxides, and transition metal chalcogenides, in chemical detection via SERS are presented. The background of the SERS concept, including its basic theory and sensing mechanism, along with the salient features of different nanomaterials used as substrates in SERS, extending from monometallic nanoparticles to nanometal oxides, is comprehensively discussed. The importance of 2D inorganic nanomaterials in SERS enhancement, along with their application toward chemical detection, is explained in detail with suitable examples and illustrations. In conclusion, some guidelines are presented for the development of this promising field in the future.

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“…Recently, many works have reported the design of Ag–Au nanohybrids because the combination of the two metals can also form hotspots with enhanced SERS sensitivity. Hence, Ag–Au bimetallic NPs, with distinct sizes and shapes, have been used in the SERS detection of a variety of organic molecules, such as dyes, thiol compounds, 3,3‐diethylthiatricarbocyanine iodide, and biomolecules . Girão et al described the synthesis of Au, Ag and colloidal nanoalloys of Ag–Au which have been used in SERS studies of rhodamine 6G .…”

Section: Sers and Water Quality Analysismentioning

confidence: 99%

Functionalized Inorganic Nanoparticles for Magnetic Separation and SERS Detection of Water Pollutants

et al. 2018

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Inorganic nanoparticles (NPs) have emerged in the last decades as key materials for a number of technologies. In particular, noble metal (Ag, Au) and iron oxide NPs have revealed important applications due to their plasmonic and magnetic properties, respectively. Among these applications, this review provides, on one hand, an overview on the use of colloidal metal NPs in surface enhanced Raman scattering (SERS) chemical analysis and, on the other hand, the application of iron oxides as a new class of nanosorbents for water pollutants. These distinct types of NPs are the main building blocks to produce [a] Raman spectroscopy is a powerful analytical tool for chemical characterization, providing information about molecular structure, surface processes, and interface reactions. [31,32] Raman spectroscopy is based on the inelastic scattering of photons by chemical species and materials (Raman scattering). Among the incident photons that hit the sample only a small portion is inelastically scattered, i.e. comes out at a different frequency from the incident light. The spectral information is based on the detection of these scattered photons that are recorded as energy shifts (Raman shifts) from the wavenumber of the elastic scattered photons (Rayleigh scattering). Each band in the Raman spectrum can be assigned to a vibrational mode (or Paula

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Bimetallic gold core–silver shell nanorod performance for surface enhanced Raman spectroscopy

Abstract: Plasmonic gold nanorods (AuNRs) coated with four different thickness silver shells (AuNR\Ags) were synthesized and tested for their efficiency in Surface Enhanced Raman Scattering (SERS) signal enhancement for biomedical applications.

Cited by 20 publications

References 51 publications

Superabsorbing Metasurfaces with Hybrid Ag–Au Nanostructures for Surface‐Enhanced Raman Spectroscopy Sensing of Drugs and Chemicals

Superabsorbing Metasurfaces with Hybrid Ag–Au Nanostructures for Surface‐Enhanced Raman Spectroscopy Sensing of Drugs and Chemicals

Recent Advances in 2D Inorganic Nanomaterials for SERS Sensing

Functionalized Inorganic Nanoparticles for Magnetic Separation and SERS Detection of Water Pollutants

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