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 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.

scholarly journals Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

2017 ◽  
Vol 8 ◽  
pp. 2492-2503 ◽  
Author(s):  
Somi Kang ◽  
Sean E Lehman ◽  
Matthew V Schulmerich ◽  
An-Phong Le ◽  
Tae-woo Lee ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Refractive Index ◽  
Electric Fields ◽  
Surface Enhanced Raman Spectroscopy ◽  
Plasmonic Crystals ◽  
Metal Thickness ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Difference Time

Herein we describe the fabrication and characterization of Ag and Au bimetallic plasmonic crystals as a system that exhibits improved capabilities for quantitative, bulk refractive index (RI) sensing and surface-enhanced Raman spectroscopy (SERS) as compared to monometallic plasmonic crystals of similar form. The sensing optics, which are bimetallic plasmonic crystals consisting of sequential nanoscale layers of Ag coated by Au, are chemically stable and useful for quantitative, multispectral, refractive index and spectroscopic chemical sensing. Compared to previously reported homometallic devices, the results presented herein illustrate improvements in performance that stem from the distinctive plasmonic features and strong localized electric fields produced by the Ag and Au layers, which are optimized in terms of metal thickness and geometric features. Finite-difference time-domain (FDTD) simulations theoretically verify the nature of the multimode plasmonic resonances generated by the devices and allow for a better understanding of the enhancements in multispectral refractive index and SERS-based sensing. Taken together, these results demonstrate a robust and potentially useful new platform for chemical/spectroscopic sensing.

Identification and Characterization of Artists' Red Dyes and Their Mixtures by Surface-Enhanced Raman Spectroscopy

2007 ◽  
Vol 61 (9) ◽  
pp. 994-1000 ◽  
Author(s):  
Alyson V. Whitney ◽  
Francesca Casadio ◽  
Richard P. Van Duyne
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Carminic Acid ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Lac Dye ◽  
Silver Island

Silver film over nanospheres (AgFONs) were successfully employed as surface-enhanced Raman spectroscopy (SERS) substrates to characterize several artists' red dyes including: alizarin, purpurin, carminic acid, cochineal, and lac dye. Spectra were collected on sample volumes (1 × 10−6 M or 15 ng/μL) similar to those that would be found in a museum setting and were found to be higher in resolution and consistency than those collected on silver island films (AgIFs). In fact, to the best of the authors' knowledge, this work presents the highest resolution spectrum of the artists' material cochineal to date. In order to determine an optimized SERS system for dye identification, experiments were conducted in which laser excitation wavelengths were matched with correlating AgFON localized surface plasmon resonance (LSPR) maxima. Enhancements of approximately two orders of magnitude were seen when resonance SERS conditions were met in comparison to non-resonance SERS conditions. Finally, because most samples collected in a museum contain multiple dyestuffs, AgFONs were employed to simultaneously identify individual dyes within several dye mixtures. These results indicate that AgFONs have great potential to be used to identify not only real artwork samples containing a single dye but also samples containing dyes mixtures.

scholarly journals Surface-Enhanced Raman Spectroscopy Characterization of Breast Cell Phenotypes: Effect of Nanoparticle Geometry

2019 ◽  
Vol 2 (11) ◽  
pp. 6960-6970
Author(s):  
Richard E. Darienzo ◽  
Jingming Wang ◽  
Olivia Chen ◽  
Maurinne Sullivan ◽  
Tatsiana Mironava ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Cell Phenotypes

Applications of surface-enhanced Raman spectroscopy in detection fields

Nanomedicine ◽  
2020 ◽  
Vol 15 (30) ◽  
pp. 2971-2989 ◽  
Author(s):  
Ting Lin ◽  
Ya-Li Song ◽  
Juan Liao ◽  
Fang Liu ◽  
Ting-Ting Zeng
Keyword(s):  
Raman Spectroscopy ◽  
Medical Diagnosis ◽  
High Selectivity ◽  
Surface Enhanced Raman Spectroscopy ◽  
Molecular Structures ◽  
Spectroscopy Technique ◽  
Detection Mechanism ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Surface-enhanced Raman spectroscopy (SERS) is a Raman spectroscopy technique that has been widely used in food safety, environmental monitoring, medical diagnosis and treatment and drug monitoring because of its high selectivity, sensitivity, rapidness, simplicity and specificity in identifying molecular structures. This review introduces the detection mechanism of SERS and summarizes the most recent progress concerning the use of SERS for the detection and characterization of molecules, providing references for the later research of SERS in detection fields.

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