scholarly journals Optimized Tapered Fiber Decorated by Ag Nanoparticles for Raman Measurement with High Sensitivity

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2300
Author(s):  
Tao Li ◽  
Zhinan Yu ◽  
Zhengkun Wang ◽  
Yong Zhu ◽  
Jie Zhang
Keyword(s):  
Ag Nanoparticles ◽  
Cone Angle ◽  
High Sensitivity ◽  
Sers Substrate ◽  
Adsorption Method ◽  
Tapered Fiber ◽  
Forming Mechanism ◽  
Surface Enhanced Raman ◽  
Fiber Cone ◽  
Small Tube

A tapered fiber decorated by Ag nanoparticles is prepared as a surface-enhanced Raman scattering (SERS) substrate. There are two key parameters during the preparation process, the fiber cone angle and the density of decorated AgNPs on the fiber tip surface. Their theoretical analysis on the forming mechanism and the optimization process is studied in detail. The tapered fibers with angles from 0.5 to 30° are successfully prepared, with a chemical method in a small tube using a bending interface. AgNPs with different densities are decorated on the surface of the tapered fibers with an electrostatic adsorption method. The optimized tapered fiber SERS probe with an angle of 12° and AgNPs density of 26.67% provides the detection of Rhodamine 6G (R6G) with 10−10 mol/L.

scholarly journals Development of Effectual Substrates for SERS by Nanostructures-on flexible surfaces

2021 ◽  
Vol 2114 (1) ◽  
pp. 012084
Author(s):  
Hammad R. Humud ◽  
Fatimah Jumaah Moaen
Keyword(s):  
Raman Scattering ◽  
Ag Nanoparticles ◽  
Surface Enhanced Raman Scattering ◽  
Wave Number ◽  
Plasmonic Nanostructures ◽  
Sers Substrate ◽  
Two Dimensional ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Abstract The current study examines recent advancements in surface-enhanced Raman scattering (SERS), a technique that employs flexible surfaces as an active substrate, this surfaces consist from two-dimensional thermo-plasmonic grating. With 53 nm Au layer (was deposited on the 2D grating structure of the PDMS by the PVD method). The explosive wire technique was used to preparing Ag nanoparticles that were used for the purpose of SERS. The effect of the plasmonic nanostructures on the absorption spectra and Surface - Enhanced Raman Scattering (SERS) activities was examined. Rhodamine 6G dye was used as a probe molecule. X-Ray diffraction (XRD) was used to examine the structural characteristics of the nanoparticles. The morphology was assessed using Field Emission Scanning Electron Microscopy(FESEM). A twin beam UV-Vis Spectrophotometer was used to measure the absorption of the combined Rh6G dye (concentration 1×10“–6M) with the nanostructures. a Sunshine Raman microscope system and a 50mm objective lens, used for investigating the Raman spectra of the Rh6G combined with nanostructures. The results showed that the enhancement factor (EF) for SERS of R6G (1×M) reached to (2.2×10 3) When using Ag nanoparticles and (0.08 × 103) when R6G deposited directly on the flexible substrates without nanostructures at the wave number (1650 cm−1), we produced a recyclable, homogeneous, and highly sensitive SERS substrate with dependable reproducibility. For the SERS substrate, a surface made up of two-dimensional (2D) flexible grating substrates was chosen to provide multiple modalities in electrical and medicinal applications.

scholarly journals Organic Molecule Detection Based on SERS in Microfluidics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xin Zhang ◽  
Haiyan Zhang ◽  
Sheng Yan ◽  
Zugang Zeng ◽  
Anshou Huang ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Ag Nanoparticles ◽  
Organic Molecule ◽  
Organic Molecules ◽  
Chemical Reduction ◽  
Fdtd Method ◽  
Great Influence ◽  
High Sensitivity ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate

AbstractSensitive in situ detection of organic molecules is highly demanded in environmental monitoring. In this work, the surface enhanced Raman spectroscopy (SERS) is adopted in microfluidics to detect the organic molecules with high accuracy and high sensitivity. Here the SERS substrate in microchannel consists of Ag nanoparticles synthesized by chemical reduction. The data indicates the fabrication conditions have great influence on the sizes and distributions of Ag nanoparticles, which play an important role on the SERS enhancement. This result is further confirmed by the simulation of electromagnetic field distributions based on finite difference time domain (FDTD) method. Furthermore, the SERS spectra of organic molecule (methylene blue) obtained in this plasmonic microfluidic system exhibit good reproducibility with high sensitivity. By a combination of SERS and microfluidics, our work not only explores the research field of plasmonics but also has broad application prospects in environmental monitoring.

scholarly journals Rapid label-free SERS detection of foodborne pathogenic bacteria based on hafnium ditelluride-Au nanocomposites

2020 ◽  
Vol 13 (05) ◽  
pp. 2041004 ◽  
Author(s):  
Yang Li ◽  
Yanxian Guo ◽  
Binggang Ye ◽  
Zhengfei Zhuang ◽  
Peilin Lan ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Limit Of Detection ◽  
Principal Component ◽  
High Sensitivity ◽  
Chemical Mechanism ◽  
Sers Substrate ◽  
Label Free ◽  
Label Free Detection ◽  
Surface Enhanced Raman ◽  
Foodborne Pathogenic Bacteria

Two-dimensional (2D) nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features. Herein, 2D hafnium ditelluride (HfTe[Formula: see text], a new member of transition metal tellurides, is exploited to support gold nanoparticles fabricating HfTe2-Au nanocomposites. The nanohybrids can serve as novel 2D surface-enhanced Raman scattering (SERS) substrate for the label-free detection of analyte with high sensitivity and reproducibility. Chemical mechanism originated from HfTe2 nanosheets and the electromagnetic enhancement induced by the hot spots on the nanohybrids may largely contribute to the superior SERS effect of HfTe2-Au nanocomposites. Finally, HfTe2-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bacteria, which realize the rapid and ultrasensitive Raman test of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to [Formula: see text]. Combined with principal component analysis, HfTe2-Au-based SERS analysis also completes the bacterial classification without extra treatment.

scholarly journals Facile Fabrication of Micro/Nano Hierarchical SERS Sensor via Anisotropic Etching and Electrochemical Treatment for Malachite Green Detection

2019 ◽  
Vol 9 (23) ◽  
pp. 5237
Author(s):  
Chu-Yu Huang ◽  
Chih-Hung Chien
Keyword(s):  
Malachite Green ◽  
Fem Simulation ◽  
High Sensitivity ◽  
Practical Method ◽  
Electrochemical Treatment ◽  
Sers Substrate ◽  
Sers Substrates ◽  
Surface Enhanced Raman ◽  
Nanostructured Gold ◽  
Facile Fabrication

We propose a facile method to produce micro/nano hierarchical surface-enhanced Raman scattering (SERS) active substrates using simple steps and inexpensive costs. The proposed SERS substrate is a silicon pyramid array covered by a nanostructured gold film (AuNS @ SiPA). Through finite element method (FEM) simulation, we showed that many strong local electric field enhancements (hot spots) were formed between the nano-gap of gold nanostructures. In addition, the micron-scale pyramid structure not only increases the sensing surface area of the sensor, but also helps trap light. By combining these micro and nano structures, the proposed micro/nano hierarchical SERS sensor exhibited high sensitivity. Experimental results confirmed that the AuNS @ SiPA substrate has high sensitivity. The SERS signal enhancement factor obtained from the Rhodamine 6G (R6G) probe molecules was as high as 1 × 107 and the SERS substrates were found to be able to detect a very low concentration of 0.01 nM malachite green (MG) solution. Therefore, this study provides a novel and practical method for fabricating SERS substrates that can facilitate the use of SERS in medicine, food safety, and biotechnology.

An in situ approach for facile fabrication of robust and scalable SERS substrates

Nanoscale ◽  
2014 ◽  
Vol 6 (13) ◽  
pp. 7232-7236 ◽  
Author(s):  
Yi-Chung Wang ◽  
Joseph S. DuChene ◽  
Fengwei Huo ◽  
Wei David Wei
Keyword(s):  
High Sensitivity ◽  
Sers Substrate ◽  
Biological Detection ◽  
Sers Substrates ◽  
Widespread Implementation ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Facile Fabrication ◽  
Enhanced Raman Scattering

The widespread implementation of surface enhanced Raman scattering (SERS) techniques for chemical and biological detection requires an inexpensive, yet robust SERS substrate with high sensitivity and reproducibility.

Electrospun flexible poly(bisphenol A carbonate) nanofibers decorated with Ag nanoparticles as effective 3D SERS substrates for trace TNT detection

The Analyst ◽  
2017 ◽  
Vol 142 (24) ◽  
pp. 4756-4764 ◽  
Author(s):  
Yi Li ◽  
Rui Lu ◽  
Jinyou Shen ◽  
Weiqing Han ◽  
Xiuyun Sun ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Ag Nanoparticles ◽  
Chemical Reduction ◽  
Sers Substrate ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Tnt Detection

A flexible 3D hybrid PC/Ag surface-enhanced Raman scattering (SERS) substrate was fabricated through the combination of electrospinning and in situ chemical reduction.

scholarly journals Highly Sensitive Surface Enhanced Raman Spectroscopy from Ag Nanoparticles Decorated Graphene Sheet

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Song ◽  
Xin Li ◽  
Sweejiang Yoo ◽  
Yuan Wu ◽  
Weihua Liu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Size Distribution ◽  
Ag Nanoparticles ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Ag Nps ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Enhancement Factors ◽  
Surface Enhanced Raman

Surface enhanced Raman spectroscopy (SERS) is a powerful analytical technique and has been most intensively studied. In this work, electroless deposition is proposed for Ag nanoparticles (NPs) decorated on chemical vapor deposition (CVD) growth graphene sheets (GS) to create hybrid SERS substrate. From three aspects of size distribution, morphology, and coverage, Ag NPs controllable decoration on GS and SERS enhancement factors of the hybrid SERS substrate is investigated. 200–300 times enhanced SERS intensities are detected from the Ag NPs on GS hybrid as compared to pure GS. Controllable decoration is crucial for improving SERS enhancement factorsβEF, becauseβEFfrom quasi cubic Ag NPs on GS is 6.53 times stronger than that from spheric one; 1.6 timesβEFis detected while the Ag NPs size distribution is reduced to half, and when the coverage is doubled,βEFis nearly doubled. This controllable Ag NPs/GS hybrid is capable of serving as a high performance SERS substrate for efficient chemical and biological sensing applications.

scholarly journals Versatile Silver Nanoparticles-Based SERS Substrate with High Sensitivity and Stability

Applied Nano ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 242-256
Author(s):  
Mimi Liu ◽  
Anjuli Bhandari ◽  
Mujtaba Ali Haqqani Mohammed ◽  
Daniela R. Radu ◽  
Cheng-Yu Lai
Keyword(s):  
Silver Nanoparticles ◽  
Design Patterns ◽  
Field Enhancement ◽  
High Sensitivity ◽  
Sers Substrate ◽  
Ag Nps ◽  
Particle Spacing ◽  
Analytical Technique ◽  
Nanomolar Detection ◽  
Surface Enhanced Raman

Surface-enhanced Raman scattering has developed into a mature analytical technique useful in various applications; however, the reproducible fabrication of a portable SERS substrate with high sensitivity and good uniformity is still an ongoing pursuit. Reported herein is a rapid fabrication method of an inexpensive SERS substrate that enables sub-nanomolar detection of molecular analytes. The SERS substrate is obtained by application of silver nanoparticles (Ag NPs)-based ink in precisely design patterns with the aid of an in-house assembled printer equipped with a user-fillable pen. Finite-difference time-domain (FDTD) simulations show a 155-times Ag NP electric field enhancement for Ag nanoparticle pairs with particle spacing of 2 nm. By comparing the SERS performance of SERS substrate made with different support matrices and fabrication methods, the PET-printed substrate shows optimal performance, with an estimated sensitivity enhancement factor of 107. The quantitative analysis of rhodamine 6G absorbed on optimized SERS substrate exhibits a good linear relationship, with a correlation coefficient (R2) of 0.9998, between the SERS intensity at 610 cm−1 and the concentration in the range of 0.1 nM—1μM. The practical low limit detection of R6G is 10 pM. The optimized SERS substrates show good stability (at least one month) and have been effectively tested in the detection of cancer drugs, including doxorubicin and metvan.

β-Cyclodextrin coated SiO2@Au@Ag core–shell nanoparticles for SERS detection of PCBs

2015 ◽  
Vol 17 (33) ◽  
pp. 21149-21157 ◽  
Author(s):  
Yilin Lu ◽  
Guohua Yao ◽  
Kexi Sun ◽  
Qing Huang
Keyword(s):  
Ag Nanoparticles ◽  
Core Shell ◽  
Sers Substrate ◽  
Shell Nanoparticles ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
New Type ◽  
Enhanced Raman Scattering ◽  
Core Shell Nanoparticles

A new type of surface-enhanced Raman scattering (SERS) substrate consisting of β-cyclodextrin (β-CD) coated SiO2@Au@Ag nanoparticles (SiO2@Au@Ag@CD NPs) has been achieved.

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