scholarly journals Seed-Mediated Preparation of Ag@Au Nanoparticles for Highly Sensitive Surface-Enhanced Raman Detection of Fentanyl

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 769
Author(s):  
Yazhou Qin ◽  
Binjie Wang ◽  
Yuanzhao Wu ◽  
Jiye Wang ◽  
Xingsen Zong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Au Nanoparticles ◽  
Surface Enhanced Raman Spectroscopy ◽  
Transmission Electron ◽  
Highly Sensitive ◽  
Label Free Detection ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Seed Mediated

Bimetallic nanoparticles have received extensive attention due to their unique physical and chemical properties, including enhanced optical properties, chemical stability, and better catalytic activity. In this article, we have successfully achieved the controllable preparation of Ag@Au nanoparticles via a seed-mediated growth method. By regulating the amount of seeds—silver nanospheres—we realized that Ag@Au nanoparticles gradually changed from spherical to a sea-urchin-like structure. The structure and composition of the prepared nanoparticles were characterized via scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and high-angle circular dark field scanning transmission electron microscopy (HAADF-STEM). In addition, we use the prepared Ag@Au nanoparticles as a substrate material for highly sensitive surface-enhanced Raman spectroscopy (SERS). Using 4-aminothiophenol (4-ATP) as the test molecule, we explored the SERS enhancement effects of Ag@Au nanoparticles with different structures. Furthermore, we used Ag@Au nanoparticles for SERS to detect the drug fentanyl, and realized the label-free detection of fentanyl, with the lowest detection concentration reaching 10−7 M. This research not only provides a method for preparing bimetallic Ag@Au nanoparticles with different structures, but also provides a reference for the application of Ag@Au nanoparticles in the field of detection technology.

TNF-α detection using gold nanoparticles as a surface-enhanced Raman spectroscopy substrate

Nanomedicine ◽  
2020 ◽  
Author(s):  
Elizabeth Loredo-García ◽  
Alejandra Ortiz-Dosal ◽  
Juan Manuel Núñez-Leyva ◽  
José Luis Cuellar Camacho ◽  
Jorge Alejandro Alegría-Torres ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Raman Spectroscopy ◽  
Light Scattering ◽  
Surface Enhanced Raman Spectroscopy ◽  
Transmission Electron ◽  
Tnf Α ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Background: TNF-α is a cytokine involved in inflammation. Surface-enhanced Raman spectroscopy (SERS) could be useful in its detection. Aim: Identify the TNF-α in an aqueous solution, using gold nanoparticles (AuNPs) as a SERS substrate. Materials & methods: Raman and SERS spectra were obtained from TNF-α samples, combined with AuNPs, with decreasing concentrations of TNF-α. The samples were analyzed using optical transmission spectroscopy, dynamic light scattering, and transmission electron microscopy. Results: Transmission electron microscopy/dynamic light scattering determined a change in the average diameter of the TNF-α/AuNPs (∼9.6 nm). Raman bands obtained were associated with aromatic amino acid side chains. We observe Raman signals for TNF-α concentrations as low as 0.125 pg/ml. Conclusion: TNF-α signal at physiological concentrations was determined with SERS.

pH Dependence of the Size and Shape of the Gold Nanoparticles Prepared by Peptides

2013 ◽  
Vol 785-786 ◽  
pp. 484-487
Author(s):  
Chun Rong Wang
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Ph Dependence ◽  
Surface Enhanced Raman Spectroscopy ◽  
Gold Nanostructures ◽  
Size And Shape ◽  
Transmission Electron ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Potential Applications

The size and shape of gold nanoparticles controlled by pH was studied in the reacted solutions containing peptides (NH2-Leu-Aib-Trp-Ome) as reducing agent. The resulting gold nanostructures were characterized by transmission electron microscopy (TEM), XRD and UV-vis-NIR spectra. Different shape of gold nanoparticles such as spheres, multipod and branch were prepared by changing the pH of solution. The resulting gold nanostructures may be have potential applications in the Surface Enhanced Raman Spectroscopy (SERS) and NIR-absorbing filters and coatings.

scholarly journals Synthesis and Characterization of Resorcinarene-Encapsulated Nanoparticles

1999 ◽  
Vol 581 ◽  
Author(s):  
Alexander Wei ◽  
Kevin B. Stavens ◽  
Stephen V. Pusztay ◽  
Ronald P. Andres
Keyword(s):  
Au Nanoparticles ◽  
Surface Enhanced Raman Spectroscopy ◽  
Inorganic Nanoparticles ◽  
Transmission Electron ◽  
Surface Enhanced ◽  
New Strategy ◽  
Surface Enhanced Raman ◽  
20 Nm ◽  
Encapsulated Nanoparticles

ABSTRACTA new strategy for stabilizing inorganic nanoparticles in nonpolar solutions is described. Resorcinarenes 1-3 were synthesized and evaluated as surfactants because of their large concave headgroups with multiple contact sites. Au nanoparticles ranging from 3-20 nm in diameter were generated in the vapor phase and dispersed into dilute hydrocarbon solutions of 1-3, where they were stabilized for up to several months. Chemisorption is most likely mediated by multiple Au-O interactions, as indicated by several control experiments and by surface-enhanced Raman spectroscopy. The resorcinarenes were readily displaced by dodecanethiol, which resulted in the precipitation of particles >5 nm as determined by absorption spectroscopy and transmission electron microscopy. This suggests that the mobility of the resorcinarene tailgroups are important for maintaining the larger nanoparticles in a dispersed state. Resorcinarene surfactants with stronger chemisorptive properties are currently being explored.

scholarly journals 3D Hotspot Matrix of Au Nanoparticles on Au Nanostructures with a Spacer Layer of Dithiol Molecules for Highly Sensitive Surface-Enhanced Raman Spectroscopy

2021 ◽  
Author(s):  
Dong-Jin Lee ◽  
Dae Yu Kim
Keyword(s):  
Au Nanoparticles ◽  
Three Dimensional ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Large Area ◽  
Spacer Layer ◽  
Highly Sensitive ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Abstract Engineering of efficient plasmonic hotspots has been receiving great attention to enhance the sensitivity of surface-enhanced Raman scattering (SERS). In the present study, we propose a highly sensitive SERS platform based on Au nanoparticles (AuNPs) on Au nanostructures (AuNSs) with a spacer layer of 1,4-benzenedimethanethiol (BDMT). The three-dimensional (3D) hotspot matrix has been rationally designed based on the idea of employing 3D hotspots with a vertical nanogap between AuNSs and AuNPs after generating large area two-dimensional hotspots of AuNSs. AuNP@BDMT@AuNSs are fabricated by functionalizing BDMT on AuNSs and then immobilizing AuNPs. The Raman signal of the AuNP@BDMT@AuNSs is approximately twelve times higher than that of AuNSs at 100 nM of rhodamine 6G. The AuNP@BDMT@AuNSs are then employed to detect thiram, which is used as a fungicide, with a detection limit of 13 nM. Our proposed platform thus shows significant potential for use in highly sensitive SERS sensors.

scholarly journals 3D hotspot matrix of Au nanoparticles on Au island film with a spacer layer of dithiol molecules for highly sensitive surface-enhanced Raman spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dong-Jin Lee ◽  
Dae Yu Kim
Keyword(s):  
Au Nanoparticles ◽  
Three Dimensional ◽  
Surface Enhanced Raman Spectroscopy ◽  
Island Film ◽  
Large Area ◽  
Spacer Layer ◽  
Highly Sensitive ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

AbstractEngineering of efficient plasmonic hotspots has been receiving great attention to enhance the sensitivity of surface-enhanced Raman scattering (SERS). In the present study, we propose a highly sensitive SERS platform based on Au nanoparticles (AuNPs) on Au island film (AuIF) with a spacer layer of 1,4-benzenedimethanethiol (BDMT). The three-dimensional (3D) hotspot matrix has been rationally designed based on the idea of employing 3D hotspots with a vertical nanogap between AuIF and AuNPs after generating large area two-dimensional hotspots of AuIF. AuNPs@BDMT@AuIF are fabricated by functionalizing BDMT on AuIF and then immobilizing AuNPs. The SERS performance is investigated with Rhodamine 6G as a probe molecule and the determined enhancement factor is 1.3 × 105. The AuNPs@BDMT@AuIF are then employed to detect thiram, which is used as a fungicide, with a detection limit of 13 nM. Our proposed platform thus shows significant potential for use in highly sensitive SERS sensors.

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