scholarly journals Distinctly Different Morphologies of Bimetallic Au-Ag Nanostructures and Their Application in Submicromolar SERS-Detection of Free Base Porphyrin

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2185
Author(s):  
Iveta Vilímová ◽  
Karolína Šišková
Keyword(s):  
Electronic Absorption Spectra ◽  
Free Base ◽  
Au Nps ◽  
Sers Substrates ◽  
Transmission Electron ◽  
Key Factor ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Application Potential ◽  
Enhanced Raman Scattering

Core-shell Au-Ag nanostructures (Au-AgNSs) are prepared by a seed-meditated growth, i.e., by a two-step process. The synthetic parameters greatly influence the morphologies of the final bimetallic Au-AgNSs, their stability and application potential as surface-enhanced Raman scattering (SERS) substrates. Direct comparison of several types of Au NPs possessing different surface species and serving as seeds in Au-AgNSs synthesis is the main objective of this paper. Borohydride-reduced (with varying stages of borohydride hydrolysis) and citrate-reduced Au NPs were prepared and used as seeds in Au-AgNSs generation. The order of reactants in seed-mediated growth procedure represents another key factor influencing the final Au-AgNSs characteristics. Electronic absorption spectra, dynamic light scattering, zeta potential measurements, energy dispersive spectroscopy and transmission electron microscopy were employed for Au-AgNSs characterization. Subsequently, possibilities and limitations of SERS-detection of unperturbed cationic porphyrin, 5,10,15,20-tetrakis(1-methyl-4-pyridyl)21H,23H-porphine (TMPyP), were investigated by using these Au-AgNSs. Only the free base (unperturbed) SERS spectral form of TMPyP is detected in all types of Au-AgNSs. It reports about a well-developed envelope of organic molecules around each Au-AgNSs which prevents metalation from occuring. TMPyP, attached via ionic interaction, was successfully detected in 10 nM concentration due to Au-AgNSs.

Stable and Recyclable SERS Substrates Based on Au-Loaded PET Nanocomposite Superhydrophobic Surfaces

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850053 ◽  
Author(s):  
Hua-Xiang Chen ◽  
Yu-Ting Wang ◽  
Ting-Ting You ◽  
Jin Zhai ◽  
Peng-Gang Yin
Keyword(s):  
Hot Spots ◽  
Physical Vapor Deposition ◽  
Deposition Process ◽  
Superhydrophobic Surfaces ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Enhanced Raman Scattering ◽  
Target Molecules

Novel surface-enhanced Raman scattering (SERS) substrates with stable and recyclable properties have been prepared by assembling gold nanoparticles-loaded PET (AuNPs/PET) nanocomposite superhydrophobic surfaces. After a physical vapor deposition process, the AuNPs/PET surfaces with vast plasmonic “hot spots” showed superhydrophobic properties, and it can hold target molecules droplets for rapid SERS detection. From blown off droplets and rinsed substrates with water after detection, we found that no probe molecules remained on the surfaces from Raman spectra. The prepared substrates were not contaminated in the detection process. Furthermore, the new SERS substrates were used for rapidly detecting droplets of crystal violet (CV) and the lowest detection concentration was about [Formula: see text] M. The as-prepared AuNPs/PET substrates also have good performance in terms of reproducibility and recyclability.

scholarly journals Real-time dynamic SERS detection of galectin using glycan-decorated gold nanoparticles

2017 ◽  
Vol 205 ◽  
pp. 363-375 ◽  
Author(s):  
Judith Langer ◽  
Isabel García ◽  
Luis M. Liz-Marzán
Keyword(s):  
Gold Nanoparticles ◽  
Fast Time ◽  
Specific Detection ◽  
Natural Conditions ◽  
Au Nps ◽  
Time Dynamic ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Enhanced Raman Scattering

We present the application of surface-enhanced Raman scattering (SERS) spectroscopy for the fast, sensitive and highly specific detection of the galectin-9 (Gal-9) protein in binding buffer (mimicking natural conditions). The method involves the use of specifically designed nanotags comprising glycan-decorated gold nanoparticles encoded with 4-mercaptobenzoic acid. At fast time scales Gal-9 can be detected down to a concentration of 1.2 nM by monitoring the SERS signal of the reporter, driven by aggregation of the functionalized Au NPs tags, induced by Gal-9 recognition. We additionally demonstrate that the sensitivity and concentration working range of the sensor can be tuned via control of aggregation dynamics and cluster size distribution.

Gold-nanoparticle, functionalized-porous-polymer monolith enclosed in capillary for on-column SERS detection

2015 ◽  
Vol 7 (4) ◽  
pp. 1349-1357 ◽  
Author(s):  
Yingcheng Pan ◽  
Xuan Wang ◽  
Han Zhang ◽  
Yan Kang ◽  
Ting Wu ◽  
...  
Keyword(s):  
Synthesis Method ◽  
Porous Polymer ◽  
Polymer Monoliths ◽  
Sers Substrates ◽  
Polymer Monolith ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Enhanced Raman Scattering ◽  
Silica Capillary

Gold nanoparticles functionalized porous polymer monoliths were developed via on-site synthesis method and enclosed in silica capillary as sensitive, uniform, and stable surface-enhanced Raman scattering (SERS) substrates.

scholarly journals SERS Amplification in Au/Si Asymmetric Dimer Array Coupled to Efficient Adsorption of Thiophenol Molecules

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1521
Author(s):  
Grégory Barbillon ◽  
Andrey Ivanov ◽  
Andrey K. Sarychev
Keyword(s):  
Detection Limit ◽  
Noble Metals ◽  
Gold Film ◽  
Plasmonic Nanostructures ◽  
Sers Substrates ◽  
Key Factor ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Asymmetric Dimer ◽  
Sers Sensing

Maximizing the surface-enhanced Raman scattering (SERS) is a significant effort focused on the substrate design. In this paper, we are reporting on an important enhancement in the SERS signal that has been reached with a hybrid asymmetric dimer array on gold film coupled to the efficient adsorption of thiophenol molecules on this array. Indeed, the key factor for the SERS effect is the adsorption efficiency of chemical molecules on the surface of plasmonic nanostructures, which is measured by the value of the adsorption constant usually named K. In addition, this approach can be applied to several SERS substrates allowing a prescriptive estimate of their relative performance as sensor and to probe the affinity of substrates for a target analyte. Moreover, this prescriptive estimate leads to higher predictability of SERS activity of molecules, which is also a key point for the development of sensors for a broad spectrum of analytes. We experimentally investigated the sensitivity of the Au/Si asymmetric dimer array on the gold film for SERS sensing of thiophenol molecules, which are well-known for their excellent adsorption on noble metals and serving as a proof-of-concept in our study. For this sensing, a detection limit of 10 pM was achieved as well as an adsorption constant K of 6 × 106 M−1. The enhancement factor of 5.2 × 1010 was found at the detection limit of 10 pM for thiophenol molecules.

scholarly journals Fabrication of Au-Nanoparticle-Decorated Cu Mesh/Cu(OH)2 @HKUST-1 Nanorod Arrays and Their Applications in Surface-Enhanced Raman Scattering

2021 ◽  
Vol 14 (1) ◽  
pp. 228
Author(s):  
Xiaoqiao Huang ◽  
Li Cai ◽  
Tingting Fan ◽  
Kexi Sun ◽  
Le Yao ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Three Dimensional ◽  
Surface Enhanced Raman Scattering ◽  
Au Nanoparticle ◽  
Nanorod Arrays ◽  
Au Nps ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Here we report a simple fabrication method for large-scale hybrid surface-enhanced Raman scattering (SERS) active substrates composed of Au-nanoparticle-decorated three-dimensional (3D) Cu(OH)2@HKUST-1 (Cu3(btc)2, H3btc = 1,3,5-benzenetricarboxylic acid) nanorod arrays on a woven Cu mesh (Cu mesh/Cu(OH)2@HKUST-1@Au). Cu(OH)2 nanorods were first obtained from a simple in situ chemical engraving Cu mesh and then utilized as self-sacrificing templates to achieve HKUST-1 nanocube-assembled nanorods; finally, Au nanoparticles (Au NPs) were sputtered onto the Cu(OH)2@HKUST-1 nanorods. Due to the large surface area, the three-dimensional Cu mesh/Cu(OH)2@HKUST-1 nanorods could load high-density Au NPs and capture target detection molecules, which is beneficial to the formation of a strong electromagnetic field coupling between Au NPs, and provides abundant “hot spots” for a sensitive and uniform SERS effect. Using the Cu mesh/Cu(OH)2@HKUST-1@Au nanorod arrays as the SERS substrate, 10−9 M Rhodamine 6G and 10−8 M 4-aminothiophenolcan were identified. To verify their practical application, the fabricated arrays were employed as SERS substrates for the detection of thiram, and 10−8 M thiram could be recognized. The hybrid SERS substrates show potential applications in the field of environmental pollutant detection and this is of great significance to the sustainable development of the environment.

scholarly journals Synthesis of Densely Immobilized Gold-Assembled Silica Nanostructures

2021 ◽  
Vol 22 (5) ◽  
pp. 2543
Author(s):  
Bomi Seong ◽  
Sungje Bock ◽  
Eunil Hahm ◽  
Kim-Hung Huynh ◽  
Jaehi Kim ◽  
...  
Keyword(s):  
Potential Method ◽  
Sers Substrate ◽  
Chloroauric Acid ◽  
Au Nps ◽  
Sio2 Surface ◽  
Color Changes ◽  
Surface Enhanced Raman ◽  
Nanoparticle Preparation ◽  
Enhanced Raman Scattering ◽  
20 Nm

In this study, dense gold-assembled SiO2 nanostructure (SiO2@Au) was successfully developed using the Au seed-mediated growth. First, SiO2 (150 nm) was prepared, modified by amino groups, and incubated by gold nanoparticles (ca. 3 nm Au metal nanoparticles (NPs)) to immobilize Au NPs to SiO2 surface. Then, Au NPs were grown on the prepared SiO2@Au seed by reducing chloroauric acid (HAuCl4) by ascorbic acid (AA) in the presence of polyvinylpyrrolidone (PVP). The presence of bigger (ca. 20 nm) Au NPs on the SiO2 surface was confirmed by transmittance electronic microscopy (TEM) images, color changes to dark blue, and UV-vis spectra broadening in the range of 450 to 750 nm. The SiO2@Au nanostructure showed several advantages compared to the hydrofluoric acid (HF)-treated SiO2@Au, such as easy separation, surface modification stability by 11-mercaptopundecanoic acid (R-COOH), 11-mercapto-1-undecanol (R-OH), and 1-undecanethiol (R-CH3), and a better peroxidase-like catalysis activity for 5,5′-Tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) reaction. The catalytic activity of SiO2@Au was two times better than that of HF-treated SiO2@Au. When SiO2@Au nanostructure was used as a surface enhanced Raman scattering (SERS) substrate, the signal of 4-aminophenol (4-ATP) on the surface of SiO2@Au was also stronger than that of HF-treated SiO2@Au. This study provides a potential method for nanoparticle preparation which can be replaced for Au NPs in further research and development.

A sensitive SERS assay for detecting proteins and nucleic acids using a triple-helix molecular switch for cascade signal amplification

2014 ◽  
Vol 50 (66) ◽  
pp. 9409-9412 ◽  
Author(s):  
Sujuan Ye ◽  
Yanying Wu ◽  
Wen Zhang ◽  
Na Li ◽  
Bo Tang
Keyword(s):  
Nucleic Acids ◽  
Signal Amplification ◽  
Triple Helix ◽  
Detection System ◽  
Molecular Switch ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Multiple Cycle ◽  
Enhanced Raman Scattering

A sensitive surface-enhanced Raman scattering (SERS) detection system is developed for proteins and nucleic acids based on a triple-helix molecular switch for multiple cycle signal amplification.

High resolution scanning near field mapping of enhancement on SERS substrates: comparison with photoemission electron microscopy

2016 ◽  
Vol 18 (14) ◽  
pp. 9405-9411 ◽  
Author(s):  
C. Awada ◽  
J. Plathier ◽  
C. Dab ◽  
F. Charra ◽  
L. Douillard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Near Field ◽  
Spectroscopic Technique ◽  
Proof Of Concept ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Photoemission Electron

The need for a dedicated spectroscopic technique with nanoscale resolution to characterize SERS substrates pushed us to develop a proof of concept of a functionalized tip–surface enhanced Raman scattering (FTERS) technique.

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