Nanomaterials
·
2019
·Vol. 9
·期 2
·185
·
IF 4.034
Junqi Tang,Quanhong Ou,Haichun Zhou,Limin Qi,Shiqing Man
A seed-mediated electroless deposition (SMED) approach for fabrication of large-area and uniform gold nanoparticle films as efficient and reproducible as surface-enhanced Raman scattering (SERS) substrates was presented. This approach involved a seeding pretreatment procedure and a subsequent growth step. The former referred to activation of polylysine-coated glass slides in gold seed solution, and the latter required a careful control of the reactant concentration and reaction time. With the aid of gold seeds and appropriate reaction conditions, a large-area and uniform nanofilm with evenly distributed gold nanoparticles (Au NPs) was formed on the surface of the substrates after adding a mixed solution containing ascorbic acid and trisodium citrate. The morphology of the Au nanofilm was examined by scanning electron microscopy. The size evolution of Au NPs on the surface of the substrates was analyzed in detail. The nanofilm substrate was prepared by reaction conditions of the seeded activation process: 10 mL ascorbic acid and trisodium citrate mixture and 30 min of soaking time, which exhibited an excellent uniformity and reproducibility of SERS enhancement with relative standard deviation (RSD) values of less than 8% (particularly, a RSD value of 3% can be reached for the optimized measurement). Compared to the common electroless deposition, the seed-mediated electroless deposition possessed inherent advantages in controllability, reproducibility, and economic benefit.Keywords:electroless deposition;nanoparticles;nanofilm;SERS;in situ chemical reduction
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Li-Xian Chen,Jing-Jing Lv,Ai-Jun Wang,Hong Huang,Jiu-Ju Feng
Well-defined gold nanoflower chains (Au NFCs) were simply fabricated on a large scale by a rapid, surfactant-free, seed-free, and template-free wet-chemical method, only with the assistance of urea. It was found that the synthesis and assembly of Au NFCs were almost simultaneously completed. The as-obtained Au nanostructures were primarily characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and UV–vis spectroscopy. The possible formation mechanism was discussed. The as-fabricated Au NFCs exhibited significant surface-enhanced Raman scattering (SERS) enhancement using p -aminothiophenol as a bench-model probe.
研究领域:
纳米材料
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Haibao Zhang,Yongxing Lin,Chunhong Qiao,Liang Wang,Cheng Cai,Hui He,Xingyou Tian
Au nanotube-based composite membrane served as surface-enhanced Raman scattering (SERS) substrate with an ultralarge aspect ratio possesses an excellent flexibility and widely tunable surface plasmon resonance, and by introducing graphene oxide (GO) as a spacer layer, the SERS enhancement of the composite membrane is obviously better than those from the individual blocks of the Au nanotubes (AuNTS) membrane and the Au nanoparticle/graphene oxide (AuNP/GO) membrane. Such a “sandwich” (AuNP/GO/AuNT) structured membrane has a high SERS sensitivity and a wide tunability by controlling the size of Au nanoparticles and the thickness of graphene oxide, and the detection limits of the AuNP/GO/AuNT substrate for R6G and NBA are as low as 10–12 and 10–7 M, respectively; the large enhancement is attributed to the adsorption and chemical mechanism of graphene oxide and the physical mechanism of the Au nanoparticles and nanotubes (the electromagnetic field coupling between them).
研究领域:
材料科学
·
纳米技术
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sensors
·
2024
·
IF 8.2
Ying Xu,Zhiyu Li,Yuanrong Liao,Jun Wang,Tong Zhang,Xifu Liu,Yang Zhang
Noble metal nanoparticle (NMP)-based composite substrates have garnered significant attention as a highly promising technique for surface-enhanced Raman scattering (SERS) in diverse scientific disciplines because their remarkable ability to amplify and functionalize Raman signals has positioned them as valuable tools for molecular detection. However, optimizing the size and distribution of NMPs has not received sufficient emphasis because of challenges associated with the precise control of deposition and the modulation of reducing rates during growth. In this research, we achieved the optimized size and spatial patterns of AgNWs on electrospun poly(vinylidene fluoride) (PVDF) nanofibers by utilizing a polydopamine (PDA) layer as a mild and controllable reduction mediator, by which the size and density of the AgNWs could be relatively precisely manipulated, achieving a dense distribution of effective “hot spots”. On the other hand, harnessing the inherent piezoelectric properties of the electrospun PVDF nanofibers further boosted the LSPR effect during the SERS test, forming a flexible dual-enhancing composite SERS substrate with excellent sensitivity. In addition to addressing structural aspects, exploiting synergistic systems capable of transferring external energy or forces to enhance the SERS performances presents a compelling avenue to broaden the practical applications of SERS. The dual-enhanced substrate achieved an exceptional enhancement factor (EF) of 1.05 × 108 and a low detection limit (LOD) of 10–10 M during the SERS test. This study focuses on integrating NMPs with electrospun piezoelectric polymer nanofibers to develop a dual-enhancing SERS substrate with excellent sensitivity and practicality. The findings provide valuable insights into controllably depositing NMPs on electrospun polymer fibers and hold significant implications for the development of highly sensitive and practical SERS substrates across various applications.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Ying Chen,Hongmei Liu,Xiuting Li,Shiwei Tang,Chenjie Gu,Guodong Wei,Tao Jiang,Xingfei Zhou
Molybdenum disulfide (MoS 2 ) with promising photocatalytic activity has attracted great attention in constructing recyclable SERS substrate. Reduced graphene oxide (RGO) was chose here to in-situ grow MoS 2 nanoflowers and effectively adjust the active area of the substrate. After the decoration of Ag nanoparticles by photo-reduction, a sophisticated RGO@MoS 2 @Ag ternary nanocomposite with a maximizing SERS enhancement factor (EF) of 8.6 × 10 6 and a prominent solar photocatalytic efficiency was demonstrated. Such superior features of the nanocomposite were revealed to be endowed by the synergistic effect of the three components including the active sites of MoS 2 , the “Schottky barrier” and “hot spots” between MoS 2 and Ag, together with the molecular enrichment surface and chemical enhancement ability of RGO . An ultra-sensitive SERS-based detection and a reliable photocatalytic degradation of mixed trace molecules were finally achieved by the developed optimal ternary nanocomposite, which can meet manifold requirements for the routine supervision of biochemical molecules.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Huanhuan Sun,Hongyan Yu,Boyang Han,Junjie Ma,Rensheng Wang,Yanping Song
Pressure-induced surface-enhanced Raman spectroscopy (PI-SERS) is among the foremost achievements of high-pressure fields, benefiting from the advantage that pressure-modulated interactions between substrates and molecules overcome the weakness of individual substrates or molecules. However, the pressure corresponding to PI-SERS enhancement is currently still at a low-pressure stage within 8 GPa. Therefore, how to realize PI-SERS enhancement under higher or ultrahigh pressure remains a huge challenge. Here, we applied few-layer WS2 (FL-WS2) nanosheets as PI-SERS substrates and selected 4-mercaptobenzoic acid (4-MBA) molecules with a big energy gap as probes to explore PI-SERS enhancement in more depth. The experimental results indicate that the PI-SERS signals increase gradually as pressure increases and reaches a maximum at 18 GPa, which has set a pressure record for the PI-SERS field so far. Different from the C exciton resonance-induced SERS intensities at ambient conditions, the charge-transfer transition between FL-WS2 and 4-MBA is strengthened via the pressure-induced increase in the band gap of FL-WS2 and decrease in the highest-occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap of 4-MBA, thus enhancing PI-SERS signals accordingly. Therefore, this strategy will be beneficial for practical applications in the field of optoelectronics and for the design of other PI-SERS sensors for trace detection in complex and extreme environments.
研究领域:
材料科学
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纳米技术
·
光电子学
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2017
·Vol. 19
·期 33
·22302-22308
·
IF 4.123
Libin Yang,Di Yin,Yu Shen,Ming Yang,Xiuling Li,Xiaoxia Han,Xin Jiang,Bing Zhao
In this study, highly-dispersed TiO2 nanoparticles (NPs) with abundant active sites were synthesized by a simple sol-hydrothermal method with the assistance of surfactant polyethylene glycol (PEG) which served as an effective SERS-active substrate for the first time. The observed considerable SERS enhancement of 4-mercaptobenzoic acid (4-MBA) probe molecules on TiO2 NPs is attributed to the contribution of the charge transfer mechanism from the substrate to the probe molecule. It is suggested that PEG can act as a protective agent in the reductive calcination of the surfactant-coated nanocrystallite and consequently brings about abundant surface oxygen vacancies for TiO2 NPs, which provide more effective sites for the adsorption of probe molecules and promote the charge transfer effect and its consequent SERS enhancement. Moreover, the prepared TiO2 NPs can serve as an effective substrate for highly sensitive detection of p-aminobenzoic acid (PABA). The detection limit of PABA is as low as 1 × 10−8 M, which is the highest sensitivity among the reported determination methods. And, it proves that the prepared TiO2 substrate with abundant active sites is characterized by high stability, which offers a unique long service lifetime for SERS detection without losing its activity.
研究领域:
材料科学
·
光谱学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yuenan Pan,Qi Chu,Shuang Guo,Sila Jin,Eungyeong Park,Yeonju Park,Yantao Sun,Lei Chen,Young Mee Jung
The purpose of this paper is to study the charge transfer (CT) process of a Ag/MBA/PAN system with different thicknesses of PAN and explore its SERS enhancement mechanism. It is found that as the PAN thickness is increased, the frequency and intensity of the characteristic MBA band gradually increases. The intensity of the b 2 mode increases significantly, which is attributed to the CT mechanism. As the PAN thickness is increased, the degree of CT (ρ CT ) gradually increases, which is due to the excited SPR from Ag. The electromagnetic enhancement mechanism, which occurs at the interface between PAN and Ag, generates hot electrons and rearranges the interface between PAN and Ag, thereby promoting electron transfer for the whole CT in Ag/MBA/PAN. These results show that CT occurs from the Fermi level of Ag to the LUMO level of MBA and then to the LUMO level of PAN. Additionally, the direction of CT is verified by 2D-COS. Therefore, this study not only reveals the ultrahigh SERS activity of the substrate but also explains the detailed process of regulating the substrate through the PAN thickness, which affects the SERS mechanism. This conductive polymer will open up a new horizon of SERS research and applications.
研究领域:
材料科学
·
光谱学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Haoyu Cai,Guojun Weng,Jianjun Li,Gaofeng Wu,Jian Zhu,Junwu Zhao
Gold deposition on Au nanoparticles is a common method to control the shape and further modify the properties of nanoparticles as their properties have a strong correlation with their nanostructures. For Au nanobipyramid (Au NBP), it has advantages such as the enhancement of electric field and a higher tunability in plasmon wavelength than the Au nanorod and thus owns a greater potential in shape control. In this paper, we demonstrate a scheme of depositing Au on the surface of Au NBP with the presence of a type of ligand 2-mercaptobenzoimidazole-5-carboxylic acid (MBIA) to synthesize Au NBP@Au dimers. The growth mode of Au depositing on Au NBP can be controlled by the coverage of MBIA. As the coverage is low, with a concentration of MBIA below 0.4 mM, the rough core–shell nanostructure is synthesized; However, as the coverage is high, with a concentration of MBIA over 0.8 mM, gold deposition may form islands on the surface of Au NBP. The SERS performance of Au depositing on Au NBP can also be enhanced by growth mode. For the rough-surface core–shell growth mode, the enhancement is more significant as the EF is improved from 3.5 × 10 5 to 1.06 × 10 6 than the islands-growing growth mode due to the coupling between core and shell. And our results show that with multiple types of nanosturctures easy to obtained by changing modified ligand coverage, the controlled growth has a great potential in the dimer design and SERS enhancement using Au NBP.
研究领域:
纳米技术
·
材料科学
·
表面增强拉曼光谱
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 17
·175501
·
IF 3.874
Jiamin Gao,Lu Huang,Zhuomin Zhang,Gongke Li
It is of great significance to construct specially designed gold nanocrystals (AuNCs) with precisely controllable size and morphology to achieve an excellent physicochemical performance. In this work, sea urchin-shaped AuNCs with tunable plasmonic property were successfully synthesized by the hybridized double-strand poly adenine (dsPolyA) DNA-directed self-assembly technique. Hybridized dsPolyA as the directing template had suitable rigidity and upright conformation, which benefited the controllable formation of these anisotropic multi-branched AuNCs with the assistance of surfactant. The effects of essential conditions influencing the synthesis and precise morphology control were investigated in detail. COMSOL simulation was used to evaluate their electromagnetic field distribution according to their morphologies, and the result suggested that sea urchin-shaped AuNCs had abundant 'hot spots' for surface-enhanced Raman scattering (SERS) detection due to their regular nanoprotuberance structure. Finally, sea urchin-shaped AuNCs with excellent SERS and catalytic performance were applied for the quantitative analysis of food colorant and catalytic degradation of potential pollutants. The SERS enhancement factor of sea urchin-shaped AuNCs was up to 5.27 × 106, and the catalytic degradation rate for 4-NP by these AuNCs was up to −0.13min−1.
研究领域:
纳米技术
·
材料科学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Wei-Bin Wang,Jian-Jun Li,Guo-Jun Weng,Jian Zhu,Yu-Bo Guo,Jun-Wu Zhao
Herein, A novel gold-silver alloy nanobox (AuAgNB)@SiO 2 -gold nanosphere (AuNP) nanoassembly based on core–shell-satellite structure is fabricated and applied to the surface-enhanced Raman scattering (SERS) detection of S100 calcium-binding protein B protein (S100B). It contains an anisotropic hollow porous AuAgNB core with rough surface, an ultrathin silica interlayer labeled with reporter molecules, and AuNP satellites. The nanoassemblies were systematically optimized by tuning the reporter molecules concentration, silica layer thickness, AuAgNB size, and the size and number of AuNP satellite size. Remarkably, AuNP satellites are adjacent to [email protected] 2 , developing AuAg-SiO 2 -Au heterogeneous interface. With the strong plasmon coupling between AuAgNB and AuNP satellites, chemical enhancement from heterogeneous interface, and the tip “hot spots” of AuAgNB, the SERS activity of the nanoassemblies was multiply enhanced. Additionally, the stability of nanostructure and Raman signal was significantly improved by the silica interlayer and AuNP satellites. Eventually, the nanoassemblies were applied for S100B detection. It demonstrated satisfactory sensitivity and reproducibility with a wide detection range of 10 fg/mL-10 ng/mL and a limit of detection (LOD) of 1.7 fg/mL. This work based on the [email protected] 2 -AuNP nanoassemblies with multiple SERS enhancements and favorable stability demonstrates the promising application in stroke diagnosis.
研究领域:
纳米技术
·
分析化学
·
生物医学工程
·
材料科学
✓ 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）