scholarly journals Preparation of Hydrophobic Film by Electrospinning for Rapid SERS Detection of Trace Triazophos

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4120
Author(s):  
Fei Shao ◽  
Jiaying Cao ◽  
Ye Ying ◽  
Ying Liu ◽  
Dan Wang ◽  
...  
Keyword(s):  
Hot Spots ◽  
Large Scale ◽  
Limit Of Detection ◽  
Small Region ◽  
Sers Substrate ◽  
Ag Nps ◽  
Electrospinning Technique ◽  
Heterocyclic Molecules ◽  
Surface Enhanced Raman ◽  
Sers Detection

For real application, it is an urgent demand to fabricate stable and flexible surface-enhanced Raman scattering (SERS) substrates with high enhancement factors in a large-scale and facile way. Herein, by using the electrospinning technique, a hydrophobic and flexible poly(styrene-co-butadiene) (SB) fibrous membrane is obtained, which is beneficial for modification of silver nanoparticles (Ag NPs) colloid in a small region and then formation of more “hot spots” by drying; the final SERS substrate is designated as Ag/SB. Hydrophobic Ag/SB can efficiently capture heterocyclic molecules into the vicinity of hot spots of Ag NPs. Such Ag/SB films are used to quantitatively detect trace triazophos residue on fruit peels or in the juice, and the limit of detection (LOD) of 2.5 × 10−8 M is achieved. Ag/SB films possess a capability to resist heat. As a case, 6-mercaptopurine (6MP) that just barely dissolves in 90 °C water is picked for conducting Ag/SB-film-based experiments.

scholarly journals Flexible and Reusable Ag Coated TiO2 Nanotube Arrays for Highly Sensitive SERS Detection of Formaldehyde

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1199 ◽  
Author(s):  
Tong Zhu ◽  
Hang Wang ◽  
Libin Zang ◽  
Sila Jin ◽  
Shuang Guo ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Surface Enhanced Raman Spectroscopy ◽  
Catalytic Performance ◽  
Tio2 Nanotube ◽  
Detection Sensitivity ◽  
Sers Substrate ◽  
Environmental Media ◽  
Sensing Platform ◽  
Surface Enhanced Raman ◽  
Sers Detection

Quantitative analysis of formaldehyde (HCHO, FA), especially at low levels, in various environmental media is of great importance for assessing related environmental and human health risks. A highly efficient and convenient FA detection method based on surface-enhanced Raman spectroscopy (SERS) technology has been developed. This SERS-based method employs a reusable and soft silver-coated TiO2 nanotube array (TNA) material, such as an SERS substrate, which can be used as both a sensing platform and a degradation platform. The Ag-coated TNA exhibits superior detection sensitivity with high reproducibility and stability compared with other SERS substrates. The detection of FA is achieved using the well-known redox reaction of FA with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (AHMT) at room temperature. The limit of detection (LOD) for FA is 1.21 × 10−7 M. In addition, the stable catalytic performance of the array allows the degradation and cleaning of the AHMT-FA products adsorbed on the array surface under ultraviolet irradiation, making this material recyclable. This SERS platform displays a real-time monitoring platform that combines the detection and degradation of FA.

scholarly journals Facilely Flexible Imprinted Hemispherical Cavity Array for Effective Plasmonic Coupling as SERS Substrate

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3196
Author(s):  
Jihua Xu ◽  
Jinmeng Li ◽  
Guangxu Guo ◽  
Xiaofei Zhao ◽  
Zhen Li ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Mechanical Stability ◽  
Coupling Effect ◽  
Low Cost ◽  
Flexible Substrate ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Ag Nps ◽  
Surface Enhanced Raman ◽  
Sers Detection

The focusing field effect excited by the cavity mode has a positive coupling effect with the metal localized surface plasmon resonance (LSPR) effect, which can stimulate a stronger local electromagnetic field. Therefore, we combined the self-organizing process for component and array manufacturing with imprinting technology to construct a cheap and reproducible flexible polyvinyl alcohol (PVA) nanocavity array decorating with the silver nanoparticles (Ag NPs). The distribution of the local electromagnetic field was simulated theoretically, and the surface-enhanced Raman scattering (SERS) performance of the substrate was evaluated experimentally. The substrate shows excellent mechanical stability in bending experiments. It was proved theoretically and experimentally that the substrate still provides a stable signal when the excited light is incident from different angles. This flexible substrate can achieve low-cost, highly sensitive, uniform and conducive SERS detection, especially in situ detection, which shows a promising application prospect in food safety and biomedicine.

scholarly journals Surface Enhanced Raman Spectroscopy Detection of Sodium Thiocyanate in Milk Based on the Aggregation of Ag Nanoparticles

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1363 ◽  
Author(s):  
Yanting Feng ◽  
Rijian Mo ◽  
Ling Wang ◽  
Chunxia Zhou ◽  
Pengzhi Hong ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Trichloroacetic Acid ◽  
Limit Of Detection ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sodium Thiocyanate ◽  
Ag Nps ◽  
Trichloroacetic Acid Solution ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection

A method is developed for detecting the concentration of sodium thiocyanate (NaSCN) in milk based on surface-enhanced Raman scattering (SERS) technology. A trichloroacetic acid solution can be used to enhance the SERS signal because of its function in promoting the aggregation of Ag nanoparticles (Ag NPs). Meanwhile, the protein in milk would be precipitated as trichloroacetic acid added and the interference from protein could be reduced during the detection. In this work, the enhancement factor (EF) is 7. 56 × 105 for sodium thiocyanate in water and the limit of detection (LOD) is 0.002 mg/L. Meanwhile, this method can be used to detect the concentration of sodium thiocyanate in milk. Results show that SERS intensity increased as the concentration of sodium thiocyanate increase from 10 to 100 mg/L. The linear correlation coefficient is R2 = 0.998 and the detection limit is 0.04 mg/L. It is observed that the concentration of sodium thiocyanate does not exceed the standard in the three kinds of milk. The confirmed credibility of SERS detection is compared with conventional methods.

scholarly journals Facial Fabrication of Large-Scale SERS-Active Substrate Based on Self-Assembled Monolayer of Silver Nanoparticles on CTAB-Modified Silicon for Analytical Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3250
Author(s):  
Juanjuan Guo ◽  
Yang Xu ◽  
Caili Fu ◽  
Longhua Guo
Keyword(s):  
Single Molecule ◽  
Large Scale ◽  
Limit Of Detection ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Self Assembled Monolayer ◽  
Single Molecule Level ◽  
Analytical Technique ◽  
Relative Standard ◽  
Surface Enhanced Raman

Surface-enhanced Raman spectroscopy (SERS) has been proven to be a promising analytical technique with sensitivity at the single-molecule level. However, one of the key problems preventing its real-world application lies in the great challenges that are encountered in the preparation of large-scale, reproducible, and highly sensitive SERS-active substrates. In this work, a new strategy is developed to fabricate an Ag collide SERS substrate by using cetyltrimethylammonium bromide (CTAB) as a connection agent. The developed SERS substrate can be developed on a large scale and is highly efficient, and it has high-density “hot spots” that enhance the yield enormously. We employed 4-methylbenzenethiol(4-MBT) as the SERS probe due to the strong Ag–S linkage. The SERS enhancement factor (EF) was calculated to be ~2.6 × 106. The efficacy of the proposed substrate is demonstrated for the detection of malachite green (MG) as an example. The limit of detection (LOD) for the MG assay is brought down to 1.0 × 10−11 M, and the relative standard deviation (RSD) for the intensity of the main Raman vibration modes (1620, 1038 cm−1) is less than 20%.

scholarly journals Large-Scale Fabrication of Ultrasensitive and Uniform Surface-Enhanced Raman Scattering Substrates for the Trace Detection of Pesticides

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 520 ◽  
Author(s):  
Jia Zhu ◽  
Guanzhou Lin ◽  
Meizhang Wu ◽  
Zhuojie Chen ◽  
Peimin Lu ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Large Scale ◽  
Capillary Flow ◽  
Surface Enhanced Raman Scattering ◽  
Ag Nps ◽  
Uniform Size ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Technology transfer from laboratory into practical application needs to meet the demands of economic viability and operational simplicity. This paper reports a simple and convenient strategy to fabricate large-scale and ultrasensitive surface-enhanced Raman scattering (SERS) substrates. In this strategy, no toxic chemicals or sophisticated instruments are required to fabricate the SERS substrates. On one hand, Ag nanoparticles (NPs) with relatively uniform size were synthesized using the modified Tollens method, which employs an ultra-low concentration of Ag+ and excessive amounts of glucose as a reducing agent. On the other hand, when a drop of the colloidal Ag NPs dries on a horizontal solid surface, the droplet becomes ropy, turns into a layered structure under gravity, and hardens. During evaporation, capillary flow was burdened by viscidity resistance from the ropy glucose solution. Thus, the coffee-ring effect is eliminated, leading to a uniform deposition of Ag NPs. With this method, flat Ag NPs-based SERS active films were formed in array-well plates defined by hole-shaped polydimethylsiloxane (PDMS) structures bonded on glass substrates, which were made for convenient detection. The strong SERS activity of these substrates allowed us to reach detection limits down to 10−14 M of Rhodamine 6 G and 10−10 M of thiram (pesticide).

scholarly journals Highly ordered arrays of hat-shaped hierarchical nanostructures with different curvatures for sensitive SERS and plasmon-driven catalysis

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chao Zhang ◽  
Zhaoxiang Li ◽  
Si Qiu ◽  
Weixi Lu ◽  
Mingrui Shao ◽  
...  
Keyword(s):  
Hot Spots ◽  
Hybrid Structure ◽  
Sers Substrate ◽  
Polystyrene Spheres ◽  
Hierarchical Nanostructures ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Narrow Gaps

Abstract Regulation of hot spots exhibits excellent potential in many applications including nanolasers, energy harvesting, sensing, and subwavelength imaging. Here, hat-shaped hierarchical nanostructures with different space curvatures have been proposed to enhance hot spots for facilitating surface-enhanced Raman scattering (SERS) and plasmon-driven catalysis applications. These novel nanostructures comprise two layers of metal nanoparticles separated by hat-shaped MoS2 films. The fabrication of this hybrid structure is based on the thermal annealing and thermal evaporation of self-assembled polystyrene spheres, which are convenient to control the metal particle size and the curvature of hat-shaped nanostructures. Based on the narrow gaps produced by the MoS2 films and the curvature of space, the constructed platform exhibits superior SERS capability and achieves ultrasensitive detection for toxic molecules. Furthermore, the surface catalytic conversion of p-nitrothiophenol (PNTP) to p, p′-dimercaptobenzene (DMAB) was in situ monitored by the SERS substrate. The mechanism governing this regulation of hot spots is also investigated via theoretical simulations.

scholarly journals Application of Aluminum Hydroxide for Improvement of Label-Free SERS Detection of Some Cephalosporin Antibiotics in Urine

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 91 ◽  
Author(s):  
Natalia E. Markina ◽  
Alexey V. Markin
Keyword(s):  
Aluminum Hydroxide ◽  
Surface Enhanced Raman Spectroscopy ◽  
Negative Influence ◽  
Quantitative Detection ◽  
Therapeutic Drug ◽  
Excitation Wavelength ◽  
Sers Substrate ◽  
Label Free ◽  
Surface Enhanced Raman ◽  
Sers Detection

This report is dedicated to development of surface-enhanced Raman spectroscopy (SERS) based analysis protocol for detection of antibiotics in urine. The key step of the protocol is the pretreatment of urine before the detection to minimize background signal. The pretreatment includes extraction of intrinsic urine components using aluminum hydroxide gel (AHG) and further pH adjusting of the purified sample. The protocol was tested by detection of a single antibiotic in artificially spiked samples of real urine. Five antibiotics of cephalosporin class (cefazolin, cefoperazone, cefotaxime, ceftriaxone, and cefuroxime) were used for testing. SERS measurements were performed using a portable Raman spectrometer with 638 nm excitation wavelength and silver nanoparticles as SERS substrate. The calibration curves of four antibiotics (cefuroxime is the exception) cover the concentrations required for detection in patient’s urine during therapy (25/100‒500 μg/mL). Random error of the analysis (RSD < 20%) and limits of quantification (20‒90 μg/mL) for these antibiotics demonstrate the applicability of the protocol for reliable quantitative detection during therapeutic drug monitoring. The detection of cefuroxime using the protocol is not sensitive enough, allowing only for qualitative detection. Additionally, time stability and batch-to-batch reproducibility of AHG were studied and negative influence of the pretreatment protocol and its limitations were estimated and discussed.

scholarly journals Porous carbon nanowire array for surface-enhanced Raman spectroscopy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nan Chen ◽  
Ting-Hui Xiao ◽  
Zhenyi Luo ◽  
Yasutaka Kitahama ◽  
Kotaro Hiramatsu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Porous Carbon ◽  
Hot Spots ◽  
Strong Dependence ◽  
Nanowire Array ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Abstract Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for vibrational spectroscopy as it provides several orders of magnitude higher sensitivity than inherently weak spontaneous Raman scattering by exciting localized surface plasmon resonance (LSPR) on metal substrates. However, SERS can be unreliable for biomedical use since it sacrifices reproducibility, uniformity, biocompatibility, and durability due to its strong dependence on “hot spots”, large photothermal heat generation, and easy oxidization. Here, we demonstrate the design, fabrication, and use of a metal-free (i.e., LSPR-free), topologically tailored nanostructure composed of porous carbon nanowires in an array as a SERS substrate to overcome all these problems. Specifically, it offers not only high signal enhancement (~106) due to its strong broadband charge-transfer resonance, but also extraordinarily high reproducibility due to the absence of hot spots, high durability due to no oxidization, and high compatibility to biomolecules due to its fluorescence quenching capability.

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.

Rapid fabrication of self-assembled interfacial film decorated filter paper as an excellent surface-enhanced Raman scattering substrate

2014 ◽  
Vol 6 (24) ◽  
pp. 9547-9553 ◽  
Author(s):  
Wu-Li-Ji Hasi ◽  
Shuang Lin ◽  
Xiang Lin ◽  
Xiu-Tao Lou ◽  
Fang Yang ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Filter Paper ◽  
Surface Enhanced Raman Scattering ◽  
Sers Substrate ◽  
Ag Nps ◽  
Interfacial Film ◽  
Rapid Fabrication ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

The fabrication of this paper-based SERS substrate is facile and rapid (<10 min). The coverage rate of Ag NPs is relatively high.

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