Chemosensors
·
2022
·Vol. 10
·期 11
·445
·
IF 4.229
Deyuan Mao,Xiaoyu Zhao,Jiahong Wen,Aofang Wang,Renxian Gao,Yaxin Wang
It is a challenging yet valuable work to prepare a surface-enhanced Raman scattering (SERS) substrate with low cost and high performance by simple methods. In this study, the Ag nanoparticles were sputtered on PS spheres by the magnetron sputtering, which was used as the mask to create the nanostructures by etching the spheres. Because of the heating effect in the etching process, the Ag nanoparticles gathered on the surfaces of PS spheres when the etching time was 60 s. Strong electromagnetic coupling was observed between the gathered Ag nanoparticles as confirmed by FDTD simulation and SERS signals from the probe molecule 4-mercaptobenzoic acid. This structure showed the detection limit for thiram down to 10−8M.Keywords:SERS;nano-gap;thiram
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 25
·8879-8888
·
IF 7.367
Xiu Liang,Yi-Shuo Wang,Ting-Ting You,Xiao-Juan Zhang,Nan Yang,Guang-Sheng Wang,Peng-Gang Yin
Interfacial self-assembly of ordered nanostructures at oil–water interfaces towards the fabrication of nanofilms has attracted the interest of plenty of scientists, since its discovery in 2004. Herein, further developments have been achieved, and we report a new strategy for the synthesis of a three-dimensional (3D) hierarchical nanostructure, through an interfacial synthesis driven microemulsion process. Thus, the synthesis route has been simplified, with the rigorous experimental conditions of traditional compositing technology. Combined with a two-step seed-mediated growth method for preparing uniform Ag-NPs, a plasmonic 3D MoS2-NS@Ag-NP nanostructure was successfully developed as a Surface-Enhanced Raman Scattering (SERS) active substrate, with plenty of surface hot spots, leading to an enhancement factor (EF) of 1.2 × 108 derived from both electromagnetic mechanism (EM) and chemical mechanism (CM) effects. The 3D MoS2-NS@Ag-NP nanostructure can be applied to detect trace thiram in apple juice and local lake water, with a detection limit as low as 10 ppb (42 nM), which is much lower than the maximal residue limit (MRL) of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Furthermore, quantitative analysis was achieved in the range of 10 ppb–1 ppm with good homogeneity and selectivity.
研究领域:
材料科学
·
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2023
·Vol. 15
·期 36
·4645-4655
·
IF 3.1
Chao Sun,Li Ye,Lizheng Wang,Zhiming Hu,Jianjun Ding
Aiming at the difficulty of traditional pesticide sampling, a low-cost and convenient flexible surface enhanced Raman scattering (SERS) gold core–silver shell-sponge (Au–Ag-sponge) substrate was synthesized by chemical reduction. The SERS substrate consisted of Au–AgNPs and a melamine sponge. The sponge had a rich open pore structure, which could well “capture” Au–AgNPs, generating a large number of “hot spots”. The SERS enhancement activity of the flexible substrate was characterized with rhodamine 6G (R6G) Raman probe molecules. The substrate showed good activity to 10−12 M rhodamine 6G with an enhancement factor (EF) of 7.72 × 106. Applying this substrate to the qualitative and quantitative detection of pesticide residues, the results showed that the Raman intensity was well related to the concentration of pesticide solution with the range of 0.1–10 mg L−1 of thiram and 1–10 mg L−1 of diquat. Furthermore, the substrate was analyzed by finite difference time domain (FDTD) simulation and the results were in good agreement with the experimental results. The reason for the difference in Raman signals of pesticide molecules on the same substrate was the different binding modes of Au–AgNPs on the sponge. Finally, we pointed out the advantages of flexible substrates in the field of pesticide residues, as well as future opportunities and challenges.
研究领域:
分析化学
·
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2023
·Vol. 148
·期 21
·5435-5444
·
IF 4.2
Yuqiu Wang,Shuchang Liu,Yongjun Hu,Cuicui Fu,Weiqiang Chen
We developed a highly sensitive and stable SERS-active substrate of Au@Ag@Ag core/shell/shell nanorods, formed by encapsulating Au nanorods (Au NRs) into a bilayer silver shell with Raman reporter molecules (4-mercaptobenzoic acid (4-MBA) and thiram) in the shell–shell gap. The core/shell/shell nanostructures demonstrated a high SERS enhancement and easy assembly. The important role of the bilayer silver shell in boosting the SERS intensity and detection sensitivity was revealed by comparing the performances of the Au@Ag@4-MBA@Ag NRs, Au@Ag@4-MBA NRs, and Au@4-MBA NRs. The obtained Au@Ag@4-MBA@Ag NRs exhibited a significantly promoted SERS intensity, which could reach around 2.6 times and 240 times that of the Au@Ag@4-MBA NRs and Au@4-MBA NRs, where the enhancement factor was found to be strongly correlated with the shell thickness. The controllable plasma properties and SERS effect of the Au@Ag@4-MBA@Ag NRs could be optimized by adjusting the dose of silver nitrate. The SERS substrate comprising core/shell/shell nanorods was highly reproducible and stable (retaining 83% SERS intensity after one month). Moreover, the highly sensitive detection of the pesticide thiram with a detection limit as low as 1.74 × 10−9 M was achieved by taking advantage of the great SERS response of the core/shell/shell nanostructures, which was 1–2 orders of magnitude lower than for other SERS substrates. The developed SERS substrate could be readily extended to embed other target analytes into the core/shell/shell nanostructure for novel and sensitive detection. This study could enable fresh approaches toward next-generation ultrasensitive analyte detection.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Tianna Wu,Shuo Yang,Wei Feng,Kaiyue Li,Yanru Li,Lili Wang,Rui Chen,Xiaodong Yang,Lulu Liu,Donglai Han
Equipped with surface-enhanced Raman scattering (SERS) effect and magnetic manipulation capacity, a new paradigm of recyclable SERS substrates based on Fe 3 O 4 nanoparticles (NPs) @SiO 2 @PEI-DTC adhesive layer @Au-Ag alloy quantum dots (QDs) were successfully prepared via engineering hydrothermal and seed deposition techniques. The SERS performance and uniformity of those substrates with different gold-silver (Au-Ag) weight ratios were evaluated by 4-aminothiophenol (4-ATP) molecules, revealing that the relative standard deviations (RSDs) of all substrates were less than 12 %, with the optimal SERS substrate achieving an enhancement factor (EF) of up to 1.39 × 10 5 . This phenomenon can be attributed to the magnetic core and plasmonic resonance properties of Au-Ag alloy QDs, which result in abundant interparticle hotspots in the Fe 3 O 4 @SiO 2 @PEI-DTC@Au-Ag (FSPAA) nanocomposites. Furthermore, the optimal FSPAA nanocomposite was employed as a SERS substrate for rapid non-destructive detection of thiram on fruit surfaces. The SERS signal intensity exhibited a robust manifesting a linear association with thiram concentration within the span of 1 × 10 −4 to 1 × 10 −9 M, and the minimal detectable concentration was 1.04 × 10 −10 M. The FSPAA core–shell nanocomposites exhibit high reusability and reliability and hold great promise for the practical applications in on-site assessment of food/environmental safety, as well as in spectroscopic identification of molecules adsorbed onto fruit surfaces.
研究领域:
分析化学
·
食品安全
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Huanhuan Li,Xiaofeng Luo,Suleiman A. Haruna,Muhammad Zareef,Quansheng Chen,Zhen Ding,Yiyong Yan
Pesticide residue detection in food has become increasingly important. Herein, surface-enhanced Raman scattering (SERS) coupled with an intelligent algorithm was developed for the rapid and sensitive detection of pesticide residues in tea. By employing octahedral Cu 2 O templates, Au-Ag octahedral hollow cages (Au-Ag OHCs) were developed, which improved the surface plasma effect via rough edges and hollow inner structure, amplifying the Raman signals of pesticide molecules. Afterward, convolutional neural network (CNN), partial least squares (PLS), and extreme learning machine (ELM) algorithms were applied for the quantitative prediction of thiram and pymetrozine. CNN algorithms performed optimally for thiram and pymetrozine, with correlation values of 0.995 and 0.977 and detection limits (LOD) of 0.286 and 29 ppb, respectively. Accordingly, no significant difference ( P greater than 0.05) was observed between the developed approach and HPLC in detecting tea samples. Hence, the proposed Au-Ag OHCs-based SERS technique could be utilized for quantifying thiram and pymetrozine in tea.
研究领域:
分析化学
·
食品科学
·
机器学习
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）