Fabrication of a honeycomb-like bimetallic SERS substrate for detection of triphenyltin chloride

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.

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In-Situ Grown Silver Nanoparticles on Nonwoven Fabrics Based on Mussel-Inspired Polydopamine for Highly Sensitive SERS Carbaryl Pesticides Detection

Nanomaterials ◽

10.3390/nano9030384 ◽

2019 ◽

Vol 9 (3) ◽

pp. 384 ◽

Cited By ~ 13

Author(s):

Zhiliang Zhang ◽

Tiantian Si ◽

Jun Liu ◽

Guowei Zhou

Keyword(s):

Silver Nanoparticles ◽

Collection Efficiency ◽

High Sensitivity ◽

Sers Substrate ◽

Analytical Sensitivity ◽

Sers Substrates ◽

Rapid Sampling ◽

Highly Sensitive ◽

Highly Sensitive Detection

The rapid sampling and efficient collection of target molecules from a real-world surface is fairly crucial for surface-enhanced Raman scattering (SERS) to detect trace pesticide residues in the environment and in agriculture fields. In this work, a versatile approach was exploited to fabricate a flexible SERS substrate for highly sensitive detection of carbaryl pesticides, using in-situ grown silver nanoparticles (AgNPs)on non-woven (NW) fabric surfaces based on mussel-inspired polydopamine (PDA) molecules. The obtained NW@PDA@AgNPs fabrics showed extremely sensitive and reproducible SERS signals toward crystal violet (CV) molecules, and the detection limit was as low as 1.0 × 10−12 M. More importantly, these NW@PDA@AgNPs fabrics could be directly utilized as flexible SERS substrates for the rapid extraction and detection of trace carbaryl pesticides from various fruit surfaces through a simple swabbing approach. It was identified that the detection limits of carbaryl residues from apple, orange, and banana surfaces were approximately decreased to 4.02 × 10−12, 6.04 × 10−12, and 5.03 × 10−12 g, respectively, demonstrating high sensitivity and superior reliability. These flexible substrates could not only drastically increase the collection efficiency from multifarious irregular-shaped matrices, but also greatly enhance analytical sensitivity and reliability for carbaryl pesticides. The fabricated flexible and multifunctional SERS substrates would have great potential to trace pesticide residue detection in the environment and bioscience fields.

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

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545820410047 ◽

2020 ◽

Vol 13 (05) ◽

pp. 2041004 ◽

Cited By ~ 1

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.

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A faster detection method for high-sensitivity cardiac troponin—POCT quantum dot fluorescence immunoassay

Journal of Thoracic Disease ◽

10.21037/jtd.2019.03.25 ◽

2019 ◽

Vol 11 (4) ◽

pp. 1506-1513 ◽

Cited By ~ 2

Author(s):

Peiling Zhou ◽

Haohao Liu ◽

Lan Gong ◽

Bo Tang ◽

Yabing Shi ◽

...

Keyword(s):

Quantum Dot ◽

Cardiac Troponin ◽

Detection Method ◽

High Sensitivity ◽

Fluorescence Immunoassay

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

Applied Sciences ◽

10.3390/app9235237 ◽

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.

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

Nanoscale ◽

10.1039/c4nr01712a ◽

2014 ◽

Vol 6 (13) ◽

pp. 7232-7236 ◽

Cited By ~ 4

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.

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An alternative PCR assay with high sensitivity and specificity for the detection of swine toxoplasmosis based on the GRA14 gene

10.21203/rs.3.rs-357601/v1 ◽

2021 ◽

Author(s):

Xi He ◽

Derong Zhou ◽

Yanwu Sun ◽

Yuan Zhang ◽

Xiaogang Zhang ◽

...

Keyword(s):

Detection Method ◽

Southern China ◽

Acute Infection ◽

High Sensitivity ◽

High Specificity ◽

Pcr Detection ◽

Pcr Assay ◽

Specific Primers ◽

Specificity And Sensitivity ◽

Pcr Method

Abstract Background Toxoplasma gondii, an intracellular apicomplexan protozoan parasite, can infect all warm-blooded animals. Infected swine are considered one of the most important sources of T. gondii infection in humans. Rapidly and effectively diagnosing T. gondii infection in swine is essential. PCR-based diagnostic tests have been fully developed, and very sensitive and specific PCR is crucial for the diagnosis of swine toxoplasmosis. Methods To established a high specificity and sensitivity PCR detection method for swine toxoplasmosis, we used T. gondii GRA14 gene as target to design specific primers and established a PCR detection method for swine toxoplasmosis. A total of 5462 blood specimens collected from pigs in 5 provinces and autonomous regions in southern China during 2016–2017 were assessed by the newly established GRA14 gene PCR method. Result Altogether, we used T. gondii GRA14 gene as target to design specific primers and established a high specificity and sensitivity PCR detection method for swine toxoplasmosis; in particular, this PCR method could detect T. gondii tachyzoite DNA in the acute infection phase. The GRA14 gene PCR assay detected a minimum of 2.35 tachyzoites of T. gondii, and it could be used for T. gondii detection in blood, tissue, semen, urine and waste feed specimens. The overall T. gondii infection rate was 18.9% (1033/5462) by the newly established GRA14 gene PCR method. According to statistical analysis among different regions, the positive rates of swine toxoplasmosis in the Shaanxi, Fujian and Guangdong areas in China from 2016 to 2017 were the highest, at 31.7% (44/139), 21.9% (86/391) and 18.8% (874/4645), respectively (χ2 = 84.2, P < 0.0001). Specimens collected in 2017 had a higher positive rate (19.1% or 886/4639) than those collected in 2016 (16.1% or 155/963) (χ2 = 4.5, P < 0.05). Specimens collected in autumn (39.4% or 187/474), spring (22.8% or 670/2940) and winter (18.2% or 129/709) also had higher positive rates than those collected in summer (3.8% or 57/1479) (χ2 = 427.7, P < 0.0001). Conclusions These results indicate that the new PCR method based on the T. gondii GRA14 gene would be useful for the diagnosis of swine toxoplasmosis and that it would facilitate the diagnosis of toxoplasmosis in clinical laboratories.

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

Applied Nano ◽

10.3390/applnano2030017 ◽

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.

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Detection of Melamine Based on the Fluorescence Changes of Nitrogen-Doped Carbon Dots

Journal of Spectroscopy ◽

10.1155/2021/5558280 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Wenzhi Yin ◽

Chaoqun Ma ◽

Tuo Zhu ◽

Jiao Gu ◽

Chun Zhu ◽

...

Keyword(s):

Carbon Dots ◽

Detection Method ◽

Limit Of Detection ◽

High Sensitivity ◽

Mercury Ions ◽

Measuring Range ◽

Nitrogen Doped ◽

One Step ◽

Doped Carbon Dots ◽

Nitrogen Doped Carbon

In order to determine the concentration of melamine, nitrogen-doped carbon dots (NCDs) were synthesized in one step as a fluorescent probe. Uric acid and diethylenetriamine were used as carbon source and nitrogen source, respectively. The experimental results showed that the fluorescence of NCDs can be quenched by mercury ions (Hg2+). Due to the strong coordination affinity between the carbon-nitrogen heterocyclic of melamine and Hg2+, part of Hg2+ coordinated with melamine when melamine was mixed with Hg2+. Then, the fluorescence of the added NCDs was quenched by the remaining Hg2+. Therefore, the concentration of melamine could be determined. The results show that the method has high sensitivity in wide measuring range that the linear ranges are 50–400 μg/L and 800–2500 μg/L, and the R2 is 0.997 and 0.988, respectively, with the limit of detection (LOD) of 21.76 μg/L. The NCDs are easy to fabricate, and the detection method is easy to implement. In this study, a new method for melamine detection was established, and the proposed method for melamine detection can provide some insights for food safety detection.

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