MICROCHIMICA ACTA
·
2023
·Vol. 190
·期 5
·1-10
·
IF 5.7
Teng Yuanjie,Li Xin,Chen Yingxin,Xu Pei,Pan Zaifa,Shao Kang,Sun Nan
The SERS intensity of analytes is primarily influenced by the density and distribution of hotspots, which are often difficult to manipulate or regulate. In this study, cucurbit[8]uril (CB[8]), a kind of rigid macrocyclic molecule, was introduced to achieve ~ 1-nm nanogap between gold nanoparticles to increase the density of SERS hotspots. Three kinds of estrogens (estrone (E1), bisphenol A (BPA), and hexestrol (DES)) which are molecules with weak SERS signals were targeted in the hotspots by CB[8] to further improve the sensitivity and selectivity of SERS. It was demonstrated that CB[8] can link gold nanoparticles together through carbonyl groups. In addition, the host–guest interaction of CB[8] and estrogens was proved from the nuclear magnetic resonance hydrogen and infrared spectra. In the presence of CB[8], the SERS intensities of E1, BPA, and DES were increased to 19-fold, 74-fold, and 4-fold, respectively, and the LOD is 3.75 µM, 1.19 µM, and 8.26 µM, respectively. Furthermore, the proposed SERS method was applied to actual milk sample analysis with recoveries of E1 (85.0 ~ 112.8%), BPA (83.0 ~ 103.7%), and DES (62.6 ~ 132.0%). It is expected that the proposed signal enlarging strategy can be applied to other analytes after further development. Graphical Abstract
研究领域:
分析化学
·
环境科学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Xu Dong,Lukas Ohnoutek,Yang Yang,Yiqing Feng,Tao Wang,Muhammad Ali Tahir,Ventsislav K. Valev,Liwu Zhang
Surface enhanced Raman spectroscopy (SERS) shows great promise in studying individual atmospheric aerosol. However, the lack of efficient, stable, uniform, large-array, and low-cost SERS substrates constitutes a major roadblock. Herein, a new SERS substrate is proposed for detecting individual atmospheric aerosol particles. It is based on the sphere segment void (SSV) structure of copper and silver (Cu/Ag) alloy. The SSV structure is prepared by an electrodeposition method and presents a uniform distribution, over large 2 cm2 arrays and at low cost. The substrate offers a high SERS enhancement factor (due to Ag) combined with lasting stability (due to Cu). The SSV structure of the arrays generates a high density of SERS hotspots (1.3 × 1014/cm2), making it an excellent substrate for atmospheric aerosol detection. For stimulated sulfate aerosols, the Raman signal is greatly enhanced (>50 times), an order of magnitude more than previously reported substrates for the same purpose. For ambient particles, collected and studied on a heavy haze day, the enhanced Raman signal allows ready observation of morphology and identification of chemical components, such as nitrates and sulfates. This work provides an efficient strategy for developing SERS substrate for detecting individual atmospheric aerosol.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Sen Yan,Ran An,Yongjin Zou,Nan Yang,Ying Zhang
Two-dimensional (2D) nanostructured arrays are regarded as attractive materials for surface-enhanced Raman scattering (SERS)-active substrates because of their excellent stability and signal reproducibility. We present a novel approach for fabricating stable and reusable 2D polymer colloidal monolayer on a SERS-active nanostructured Au substrate with high-density hotspots. Poly(styrene- co - N -isopropylacrylamide)@polyacrylic acid (PSN@PAA) polymer particles with core@shell structure were synthesized by a two-step polymerization. Using the soft microgel polymer particles as building blocks, a 2D close-packed PSN@PAA colloid nanofilm was fabricated at air–water interface. An ultra-thin Au nanofilm was sputtered onto the 2D PSN@PAA colloidal monolayer by a simple and efficient sputter-deposition technique. The aggregation structure of Au nanoparticles on the surface of the 2D microgel nanolayer could be regulated by shrinking the polymer microgels in methanol. Furthermore, the electrostatic interaction of sodium citrate on nanoparticles and the ripening process to Au nanoclusters could facilitate the formation of crevices. The region of Au nano-islands and nanocaps formed on the surface of the soft 2D polymer monolayer could generate very dense enhanced electromagnetic field hotspots, which can greatly enhance the Raman signals of R6G adsorbed on the substrate. The excellent reusability of the PSN@PAA/Au composite nanofilm was mainly due to the preferable adsorption of probe molecules on the 2D soft microgel particles. Moreover, the shrinkage of polymer microgel particles in the ethanol solvent made it easy to desorb the probe molecules from the substrate surface. Therefore, the macroscopic uniformity of the nanofilms ensured the reproducibility of SERS signals, providing an ideal candidate for SERS applications.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 24
·245601
·
IF 3.953
Guangming Xu,Xilong Shen,Lei Zhang,Jie Tang,Chuan He,Ziqiang Zhou,Tian Xu,Meifeng Xu,Yonglong Jin,Chaonan Wang
In this study, we developed a flexible and transparent silver/polystyrene/polydimethylsiloxane (Ag/PS/PDMS) substrate with both high density of hot spots and satisfactory uniformity using a cost-effective approach. Via template-guided self-assembly, PS beads were arranged regularly in nanobowls of a square array on PDMS, whose surface structure was transferred from a commercial complementary metal oxide semiconductor chip. Roughness was introduced onto the PS bead surface by nitrogen plasma treatment, followed by sputtering of Ag which generated many hot spots. Differential roughness on the PS bead surface greatly influenced the morphology of the Ag/PS/PDMS substrate. A meat-ball like surface structure was formed with a plasma etching time of 5 min, whose growth mechanism was proposed based on the scanning electron microscope analysis. The high sensitivity and desirable uniformity of the meat-ball like Ag/PS/PDMS substrate were demonstrated by using crystal violet as a Raman reporter, exhibiting an enhancement factor of 2.7 × 107 and a relative standard deviation of 5.04%. Thiram of a lower concentration than the maximum residue limit on the cucumber surface could easily be detected in situ by the proposed substrate, demonstrating its great potential for in-situ food safety analysis.
研究领域:
材料科学
·
分析化学
·
食品安全
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 412
·期 1
·193-201
·
IF 3.286
Sun Yu,Chen Hui,Ma Pei,Li Junying,Zhang Zheng,Shi Hao,Zhang Xuedian
A highly sensitive approach to detect trace amount of clenbuterol (CB) based on graphene oxide/gold nanoparticles (GO/Au NPs) by surface-enhanced Raman spectroscopy (SERS) was presented. To be specific, the GO/Au nanocomposites were formed by depositing Au NPs onto the surface of GO through an in situ reduction process, where a high density of inherent hot spots was created between Au NPs. By optimizing the depositing density of Au NPs, the strongest electromagnetic coupling effect originating from highly dense hot spots was obtained. The optimized GO/Au was demonstrated to enhance the Raman signals of CB by 4.8 times more than that of CB enhanced by Au NPs. Moreover, GO/Au nanocomposites exhibit good biocompatibility and accessible surface for high adsorption of target molecules through the pi-pi stacking with graphene oxide. Hence, the proposed GO/Au nanocomposites were utilized to capture aromatic molecules like CB and served as excellent sensitive SERS-active substrates for sensing of it, which exhibited an excellent linear performance in the range of 5 × 10 −8 to 1 × 10 −6 mol/L with a limit of detection (LOD) of 3.34 × 10 −8 mol/L (S/N = 3). Due to high-density hot spots with easy operation, this proposed GO/Au nanocomposite–based SERS technique holds great potential in the application of food safety analysis and biomedical science.
研究领域:
食品安全分析
·
生物医学科学
·
纳米技术
·
分析化学
✓ 已验证
DOI
高影响因子
TALANTA
·
2023
·
IF 6.1
Jiaqi Liu,Zhongshun Wang,Ya'nan Meng,Chunning Chen,Qiye Chen,Yalei Wang,Shuzhen Dou,Xiaoyang Liu,Nan Lu
Trace analysis has great promise in the fields of disease diagnosis and environment protection. Surface-enhanced Raman scattering (SERS) has wide range of utilization due to its reliable fingerprint detection. However, the sensitivity of SERS still needs to be enhanced. Raman scattering of target molecules around hotspots, the area with extremely strong electromagnetic field , can be highly amplified. Therefore, to increase the density of hotspots is one of the major approaches for enhancing the detection sensitivity of target molecules. In this paper, an ordered array of Ag nanocubes was assembled on a thiol modified silicon substrate as a SERS substrate, which provided high-density hotspots. The detection sensitivity is demonstrated by the limit of detection, which is down to 10 −6 nM with Rhodamine 6G as probe molecule. The wide linear range (10 −7 –10 −13 M) and low relative standard deviation (<6.48%) indicate the good reproducibility of the substrate. Furthermore, the substrate can be used for the detection of dye molecules in lake water. This method provides an approach for increasing hotspots of SERS substrate, which could be a promising method to achieve good reproducibility and high sensitivity.
研究领域:
分析化学
·
纳米技术
·
环境科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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