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 ◽  
...  

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.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Song ◽  
Xin Li ◽  
Sweejiang Yoo ◽  
Yuan Wu ◽  
Weihua Liu ◽  
...  

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.


2021 ◽  
pp. 000370282110329
Author(s):  
Ling Wang ◽  
Mario O. Vendrell-Dones ◽  
Chiara Deriu ◽  
Sevde Doğruer ◽  
Peter de B. Harrington ◽  
...  

Recently there has been upsurge in reports that illicit seizures of cocaine and heroin have been adulterated with fentanyl. Surface-enhanced Raman spectroscopy (SERS) provides a useful alternative to current screening procedures that permits detection of trace levels of fentanyl in mixtures. Samples are solubilized and allowed to interact with aggregated colloidal nanostars to produce a rapid and sensitive assay. In this study, we present the quantitative determination of fentanyl in heroin and cocaine using SERS, using a point-and-shoot handheld Raman system. Our protocol is optimized to detect pure fentanyl down to 0.20 ± 0.06 ng/mL and can also distinguish pure cocaine and heroin at ng/mL levels. Multiplex analysis of mixtures is enabled by combining SERS detection with principal component analysis and super partial least squares regression discriminate analysis (SPLS-DA), which allow for the determination of fentanyl as low as 0.05% in simulated seized heroin and 0.10% in simulated seized cocaine samples.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lu Pei ◽  
Yiqun Huang ◽  
Chunying Li ◽  
Yuanyuan Zhang ◽  
Barbara A. Rasco ◽  
...  

Silver-coated gold bimetallic nanoparticles were synthesized and used as substrates for surface-enhanced Raman spectroscopy (SERS) in detecting prohibited triphenylmethane drugs (including crystal violet and malachite green) in fish muscle. The optical properties and physical properties of bimetallic nanospheres were characterized by UV-Vis spectroscopy and transmission electron microscopy. The optimal nanospheres selected had relatively uniform size (diameter: 33 ± 3 nm) with a silver layer coated on the surface of gold seed (diameter: 18 ± 2 nm). For both crystal violet and malachite green, characteristic SERS spectral features could be identified at concentration as low as 0.1 μg/L with these bimetallic nanospheres. Crystal violet and malachite green residues in fish muscle could also be detected at levels as low as 0.1 ng/g, which could meet the most restricted regulatory requirements for the limit of detection in terms of analytical methods for crystal violet or malachite green in fish muscle. This study provides a basis for applying SERS technology with bimetallic nanoparticles to the identification of trace amounts of prohibited substances in aquatic food products, and the methodology could be extended to analyses of other hazardous chemicals in complex food matrices like vegetables and meats.


2011 ◽  
Vol 78 (6) ◽  
pp. 1930-1935 ◽  
Author(s):  
Suzanne L. Hennigan ◽  
Jeremy D. Driskell ◽  
Naola Ferguson-Noel ◽  
Richard A. Dluhy ◽  
Yiping Zhao ◽  
...  

ABSTRACTMycoplasma gallisepticumis a bacterial pathogen of poultry that is estimated to cause annual losses exceeding $780 million. The National Poultry Improvement Plan guidelines recommend regular surveillance and intervention strategies to containM. gallisepticuminfections and ensure mycoplasma-free avian stocks, but several factors make detection ofM. gallisepticumand diagnosis ofM. gallisepticuminfection a major challenge. Current techniques are laborious, require special expertise, and are typically plagued by false results. In this study, we describe a novel detection strategy which uses silver nanorod array–surface-enhanced Raman spectroscopy (NA-SERS) for direct detection of avian mycoplasmas. As a proof of concept for use in avian diagnostics, we used NA-SERS to detect and differentiate multiple strains of avian mycoplasma species, includingAcholeplasma laidlawii,Mycoplasma gallinarum,Mycoplasma gallinaceum,Mycoplasma synoviae, andM. gallisepticum, including vaccine strains 6/85, F, and ts-11. Chemometric multivariate analysis of spectral data was used to classify these species rapidly and accurately, with >93% sensitivity and specificity. Furthermore, NA-SERS had a lower limit of detection that was 100-fold greater than that of standard PCR and comparable to that of real-time quantitative PCR. Detection ofM. gallisepticumin choanal cleft swabs from experimentally infected birds yielded good sensitivity and specificity, suggesting that NA-SERS is applicable for clinical detection.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2508
Author(s):  
Osama Nasr ◽  
Jian-Ru Jiang ◽  
Wen-Shuo Chuang ◽  
Sheng-Wei Lee ◽  
Chih-Yen Chen

In this article, we demonstrate a facile, rapid, and practical approach to growing high-quality Cu2S nanosheets decorated with Ag nanoparticles (NPs) through the galvanic reduction method. The Ag/Cu2S nanosheets were efficiently applied to the surface-enhanced Raman scattering (SERS) and photocatalytic degradation applications. The photodegradation of RhB dye with the Ag/Cu2S nanosheets composites occurred at a rate of 2.9 times faster than that observed with the undecorated Cu2S nanosheets. Furthermore, the Ag/Cu2S nanosheets displayed highly sensitive SERS detection of organic pollutant (R6G) as low as 10−9 M. The reproducibility experiments indicated that the Ag/Cu2S nanosheets composites could be used for dual functionality in a new generation of outstandingly sensitive SERS probes for detection and stable photocatalysts.


The Analyst ◽  
2014 ◽  
Vol 139 (24) ◽  
pp. 6426-6434 ◽  
Author(s):  
Kelley C. Henderson ◽  
Edward S. Sheppard ◽  
Omar E. Rivera-Betancourt ◽  
Joo-Young Choi ◽  
Richard A. Dluhy ◽  
...  

The detection limits by NA-SERS and qPCR for the bacterial pathogenMycoplasma pneumoniaewere compared.


Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4120
Author(s):  
Fei Shao ◽  
Jiaying Cao ◽  
Ye Ying ◽  
Ying Liu ◽  
Dan Wang ◽  
...  

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.


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