scholarly journals 4-Mercaptobenzoic Acid Labeled Gold-Silver-Alloy-Embedded Silica Nanoparticles as an Internal Standard Containing Nanostructures for Sensitive Quantitative Thiram Detection

2019 ◽  
Vol 20 (19) ◽  
pp. 4841 ◽  
Author(s):  
Xuan-Hung Pham ◽  
Eunil Hahm ◽  
Kim-Hung Huynh ◽  
Byung Sung Son ◽  
Hyung-Mo Kim ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Silver Alloy ◽  
Gold Silver ◽  
Visible Spectra ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Shell Deposition ◽  
Sers Intensity

In this study, SiO2@Au@4-MBA@Ag (4-mercaptobenzoic acid labeled gold-silver-alloy-embedded silica nanoparticles) nanomaterials were investigated for the detection of thiram, a pesticide. First, the presence of Au@4-MBA@Ag alloys on the surface of SiO2 was confirmed by the broad bands of ultraviolet-visible spectra in the range of 320–800 nm. The effect of the 4-MBA (4-mercaptobenzoic acid) concentration on the Ag shell deposition and its intrinsic SERS (surface-enhanced Raman scattering) signal was also studied. Ag shells were well coated on SiO2@Au@4-MBA in the range of 1–1000 µM. The SERS intensity of thiram-incubated SiO2@Au@4-MBA@Ag achieved the highest value by incubation with 500 µL thiram for 30 min, and SERS was measured at 200 µg/mL SiO2@Au@4-MBA@Ag. Finally, the SERS intensity of thiram at 560 cm−1 increased proportionally with the increase in thiram concentration in the range of 240–2400 ppb, with a limit of detection (LOD) of 72 ppb.

scholarly journals Highly Reproducible Surface-Enhanced Raman Scattering Detection of Alternariol Using Silver-Embedded Silica Nanoparticles

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3523 ◽  
Author(s):  
Eunil Hahm ◽  
Yoon-Hee Kim ◽  
Xuan-Hung Pham ◽  
Bong-Hyun Jun
Keyword(s):  
Raman Scattering ◽  
Silica Nanoparticles ◽  
Ag Nanoparticles ◽  
Limit Of Detection ◽  
Surface Enhanced Raman Scattering ◽  
Sers Signal ◽  
Relative Standard ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Alternariol (AOH) is a mycotoxin from fungi that has been found in processed foods due to its high thermal stability. To address the complexity and costs of conventional AOH detection methods, we propose an alternative based on surface-enhanced Raman scattering (SERS) and specially designed nanoparticle substrate. Herein, silver-embedded silica (SiO2@Ag) nanoparticles with a highly reproducible SERS signal were successfully developed for detecting AOH. Silica nanoparticles (~145 nm) were used as a template to deposit silver nanoparticles (~17 nm), thereby generating SiO2@Ag. The SiO2@Ag nanoparticles showed a good linearity between SERS signal intensity and AOH concentrations from 16 to 1000 nM with a limit of detection of 4.83 nM. Additionally, the SERS signal of the SiO2@Ag nanoparticles was highly reproducible, with relative standard deviations of 2.33–5.95% in the AOH concentration range from 10 to 10,000 nM, demonstrating the reliability of the proposed SERS method.

scholarly journals Facile Histamine Detection by Surface-Enhanced Raman Scattering Using SiO2@Au@Ag Alloy Nanoparticles

2020 ◽  
Vol 21 (11) ◽  
pp. 4048 ◽  
Author(s):  
Kim-Hung Huynh ◽  
Xuan-Hung Pham ◽  
Eunil Hahm ◽  
Jaehyun An ◽  
Hyung-Mo Kim ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Limit Of Detection ◽  
Volume Ratio ◽  
Surface Enhanced Raman Scattering ◽  
Tween 20 ◽  
Histamine Concentration ◽  
Gold Silver ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Histamine intoxication associated with seafood consumption represents a global health problem. The consumption of high concentrations of histamine can cause illnesses ranging from light symptoms, such as a prickling sensation, to death. In this study, gold–silver alloy-embedded silica (SiO2@Au@Ag) nanoparticles were created to detect histamine using surface-enhanced Raman scattering (SERS). The optimal histamine SERS signal was measured following incubation with 125 μg/mL of SiO2@Au@Ag for 2 h, with a material-to-histamine solution volume ratio of 1:5 and a phosphate-buffered saline-Tween 20 (PBS-T) solvent at pH 7. The SERS intensity of the histamine increased proportionally with the increase in histamine concentration in the range 0.1–0.8 mM, with a limit of detection of 3.698 ppm. Our findings demonstrate the applicability of SERS using nanomaterials for histamine detection. In addition, this study demonstrates that nanoalloys could have a broad application in the future.

scholarly journals Fabrication and Characterization of a Highly-Sensitive Surface-Enhanced Raman Scattering Nanosensor for Detecting Glucose in Urine

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 629 ◽  
Author(s):  
Yudong Lu ◽  
Ting Zhou ◽  
Ruiyun You ◽  
Yang Wu ◽  
Huiying Shen ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Internal Standard ◽  
Surface Enhanced Raman Scattering ◽  
Quantitative Detection ◽  
Core Shell ◽  
Ag Nps ◽  
Vis Spectroscopy ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Herein we utilized coordination interactions to prepare a novel core-shell plasmonic nanosensor for the detection of glucose. Specifically, Au nanoparticles (NPs) were strongly linked with Ag+ ions to form a sacrificial Ag shell by using 4-aminothiophenol (4-PATP) as a mediator, which served as an internal standard to decrease the influence of the surrounding on the detection. The resultant Au-PATP-Ag core-shell systems were characterized by UV-vis spectroscopy, transmission electron microscopy, and surface-enhanced Raman scattering (SERS) techniques. Experiments performed with R6G (rhodamine 6G) and CV (crystal violet) as Raman reporters demonstrated that the Au@Ag nanostructure amplified SERS signals obviously. Subsequently, the Au@Ag NPs were decorated with 4-mercaptophenylboronic acid (4-MPBA) to specifically recognize glucose by esterification, and a detection limit as low as 10−4 M was achieved. Notably, an enhanced linearity for the quantitative detection of glucose (R2 = 0.995) was obtained after the normalization of the spectral peaks using 4-PATP as the internal standard. Finally, the practical applicability of the developed sensing platform was demonstrated by the detection of glucose in urine with acceptable specificity.

scholarly journals Direct Detection of Toxic Contaminants in Minimally Processed Food Products Using Dendritic Surface-Enhanced Raman Scattering Substrates

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2726 ◽  
Author(s):  
Hannah Dies ◽  
Maria Siampani ◽  
Carlos Escobedo ◽  
Aristides Docoslis
Keyword(s):  
Raman Scattering ◽  
Limit Of Detection ◽  
Screening Method ◽  
Food Products ◽  
Surface Enhanced Raman Scattering ◽  
Liquid Food ◽  
Minimally Processed ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

We present a method for the surface-enhanced Raman scattering (SERS)-based detection of toxic contaminants in minimally processed liquid food products, through the use of a dendritic silver nanostructure, produced through electrokinetic assembly of nanoparticles from solution. The dendritic nanostructure is produced on the surface of a microelectrode chip, connected to an AC field with an imposed DC bias. We apply this chip for the detection of thiram, a toxic fruit pesticide, in apple juice, to a limit of detection of 115 ppb, with no sample preprocessing. We also apply the chip for the detection of melamine, a toxic contaminant/food additive, to a limit of detection of 1.5 ppm in milk and 105 ppb in infant formula. All the reported limits of detection are below the recommended safe limits in food products, rendering this technique useful as a screening method to identify liquid food with hazardous amounts of toxic contaminants.

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