1
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Dong J, Ren Y, Zhao K, Yuan J, Han Q, Gao W, Liu J, Zhu L, Zhang Z, Qi J. Electric field-induced assembly of Au-Ag alloy nanoparticles into nano-reticulation for ultrasensitive SERS. OPTICS EXPRESS 2023; 31:21225-21238. [PMID: 37381227 DOI: 10.1364/oe.493374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/21/2023] [Indexed: 06/30/2023]
Abstract
This paper discusses a method for assembling Au-Ag alloy nanoparticles (NPs) using direct current (DC) electric field to fabricate highly active SERS substrates. Different nanostructures could be obtained by regulating the intensity and action time of DC electric field. Under the condition of 5mA*10 min, we obtained Au-Ag alloy nano-reticulation (ANR) substrate with excellent SERS activity (Enhancement factor on order of magnitude of 106). ANR substrate has excellent SERS performance due to the resonance matching between its LSPR mode and excitation wavelength. The uniformity of the Raman signal on ANR is greatly improved than bare ITO glass. ANR substrate also has the ability to detect multiple molecules: ANR substrate can respectively detect Rh6G and CV molecules with a concentration as low as 10-10 M and 10-9 M and the Raman spectral intensity of the probe molecules on the surface of the ANR substrate has good linear correlation with the molecular concentration (R2 > 0.95). In addition, ANR substrate can detect both thiram and aspartame (APM) molecules far below (thiram for 0.0024 ppm and APM for 0.0625 g/L) the safety standard, which demonstrate its practical application potential.
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2
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Deriu C, Thakur S, Tammaro O, Fabris L. Challenges and opportunities for SERS in the infrared: materials and methods. NANOSCALE ADVANCES 2023; 5:2132-2166. [PMID: 37056617 PMCID: PMC10089128 DOI: 10.1039/d2na00930g] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/15/2023] [Indexed: 06/19/2023]
Abstract
In the wake of a global, heightened interest towards biomarker and disease detection prompted by the SARS-CoV-2 pandemic, surface enhanced Raman spectroscopy (SERS) positions itself again at the forefront of biosensing innovation. But is it ready to move from the laboratory to the clinic? This review presents the challenges associated with the application of SERS to the biomedical field, and thus, to the use of excitation sources in the near infrared, where biological windows allow for cell and through-tissue measurements. Two main tackling strategies will be discussed: (1) acting on the design of the enhancing substrate, which includes manipulation of nanoparticle shape, material, and supramolecular architecture, and (2) acting on the spectral collection set-up. A final perspective highlights the upcoming scientific and technological bets that need to be won in order for SERS to stably transition from benchtop to bedside.
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Affiliation(s)
- Chiara Deriu
- Department of Applied Science and Technology, Politecnico di Torino 10129 Turin Italy
| | - Shaila Thakur
- Department of Applied Science and Technology, Politecnico di Torino 10129 Turin Italy
| | - Olimpia Tammaro
- Department of Applied Science and Technology, Politecnico di Torino 10129 Turin Italy
| | - Laura Fabris
- Department of Applied Science and Technology, Politecnico di Torino 10129 Turin Italy
- Department of Materials Science and Engineering, Rutgers University Piscataway NJ 08854 USA
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3
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Dong J, Yuan J, Cao Y, Zhao Y, Han Q, Gao W, Li T, Zhu L, Qi J. Electrically controllable self-assembly of gold nanorods into a plasmonic nanostructure for highly efficiency SERS. OPTICS LETTERS 2022; 47:6365-6368. [PMID: 36538439 DOI: 10.1364/ol.477507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/12/2022] [Indexed: 06/17/2023]
Abstract
In this Letter, a method for the rapid and efficient preparation of ultrasensitive detection substrates by assembling gold nanorod suspensions with the application of an alternating current (AC) field is proposed, and it is found that frequency and voltage are the effective means of regulation. A sandwich structure (parallel SiO2 plate) not only effectively slows down the evaporation rate, but also visually reveals the changes in the assembly process. Under the optimal assembly conditions, the sensitivity and uniformity of the substrate to different probe molecules are tested. The Raman detection results experimentally show that the detection limits of Rhodamine 6G (Rh6G), crystal violet (CV), and Aspartame (APM) molecular solutions are 10-14 M, 10-10 M, and 62.5 mg/L, respectively, and the mixed dye molecular solutions can also be effectively distinguished. Furthermore, Rh6G and CV characteristic peaks at 1647 cm-1 and 1619 cm-1 were measured at randomly selected positions, and their relative standard deviations (RSDs) were 5.63% and 8.45%, respectively, indicating that the substrate has good uniformity. The effective regulation of the self-assembly results of nanoparticles will further enhance the practical application effect of surface-enhanced Raman technology and expand the application prospects of this technology.
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4
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Pillanagrovi J, Dutta-Gupta S. Controlled assembly of gold nanoparticles in resonant gold nanoapertures for SERS applications. NANOTECHNOLOGY 2022; 33:485301. [PMID: 36001942 DOI: 10.1088/1361-6528/ac8c49] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
The controlled assembly of plasmonic nanoparticles is vital for realizing low-cost, high efficiency plasmonic substrates with tunable resonances. Here, we present a strategy to assemble gold nanoparticles (AuNPs) in resonant gold nanoapertures (NAs) to enable coupling-mediated near-field enhancement. The NAs templates are fabricated using shadow sphere lithography on polyelectrolyte (PE) coated substrates. Subsequently, AuNPs are assembled in the resonant NA templates via a simple immersion step. The PE layer, AuNP concentration, NaCl concentration, incubation time, and template thickness are used to control the particle number per aperture and the interparticle distance of the AuNP assemblies. The fabricated AuNP-NA substrates are evaluated for their SERS potential using 4-Mercaptobenzoic acid (MBA) as a Raman reporter molecule. The SERS intensity of the AuNP-NA templates can be enhanced by ten times by controlling the AuNP and NA template parameters as compared to the bare NA templates. Numerical simulations show that the coupling between the various plasmonic modes is crucial for this SERS enhancement. The proposed strategy can be used to fabricate hybrid AuNP-NA based SERS substrates with improved sensitivity.
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Affiliation(s)
- Jayakumar Pillanagrovi
- Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Hyderabad, India
| | - Shourya Dutta-Gupta
- Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Hyderabad, India
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5
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Amadi EV, Venkataraman A, Papadopoulos C. Nanoscale self-assembly: concepts, applications and challenges. NANOTECHNOLOGY 2022; 33. [PMID: 34874297 DOI: 10.1088/1361-6528/ac3f54] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 12/02/2021] [Indexed: 05/09/2023]
Abstract
Self-assembly offers unique possibilities for fabricating nanostructures, with different morphologies and properties, typically from vapour or liquid phase precursors. Molecular units, nanoparticles, biological molecules and other discrete elements can spontaneously organise or form via interactions at the nanoscale. Currently, nanoscale self-assembly finds applications in a wide variety of areas including carbon nanomaterials and semiconductor nanowires, semiconductor heterojunctions and superlattices, the deposition of quantum dots, drug delivery, such as mRNA-based vaccines, and modern integrated circuits and nanoelectronics, to name a few. Recent advancements in drug delivery, silicon nanoelectronics, lasers and nanotechnology in general, owing to nanoscale self-assembly, coupled with its versatility, simplicity and scalability, have highlighted its importance and potential for fabricating more complex nanostructures with advanced functionalities in the future. This review aims to provide readers with concise information about the basic concepts of nanoscale self-assembly, its applications to date, and future outlook. First, an overview of various self-assembly techniques such as vapour deposition, colloidal growth, molecular self-assembly and directed self-assembly/hybrid approaches are discussed. Applications in diverse fields involving specific examples of nanoscale self-assembly then highlight the state of the art and finally, the future outlook for nanoscale self-assembly and potential for more complex nanomaterial assemblies in the future as technological functionality increases.
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Affiliation(s)
- Eberechukwu Victoria Amadi
- University of Victoria, Department of Electrical and Computer Engineering, PO BOX 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
| | - Anusha Venkataraman
- University of Victoria, Department of Electrical and Computer Engineering, PO BOX 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
| | - Chris Papadopoulos
- University of Victoria, Department of Electrical and Computer Engineering, PO BOX 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
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6
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Das GM, Managò S, Mangini M, De Luca AC. Biosensing Using SERS Active Gold Nanostructures. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2679. [PMID: 34685120 PMCID: PMC8539114 DOI: 10.3390/nano11102679] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 12/04/2022]
Abstract
Surface-enhanced Raman spectroscopy (SERS) has become a powerful tool for biosensing applications owing to its fingerprint recognition, high sensitivity, multiplex detection, and biocompatibility. This review provides an overview of the most significant aspects of SERS for biomedical and biosensing applications. We first introduced the mechanisms at the basis of the SERS amplifications: electromagnetic and chemical enhancement. We then illustrated several types of substrates and fabrication methods, with a focus on gold-based nanostructures. We further analyzed the relevant factors for the characterization of the SERS sensor performances, including sensitivity, reproducibility, stability, sensor configuration (direct or indirect), and nanotoxicity. Finally, a representative selection of applications in the biomedical field is provided.
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Affiliation(s)
| | - Stefano Managò
- Laboratory of Biophotonics and Advanced Microscopy, Second Unit, Institute of Experimental Endocrinology and Oncology “G. Salvatore” (IEOS), National Research Council (CNR), Via P. Castellino 111, 80131 Naples, Italy; (G.M.D.); (M.M.)
| | | | - Anna Chiara De Luca
- Laboratory of Biophotonics and Advanced Microscopy, Second Unit, Institute of Experimental Endocrinology and Oncology “G. Salvatore” (IEOS), National Research Council (CNR), Via P. Castellino 111, 80131 Naples, Italy; (G.M.D.); (M.M.)
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7
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Ma Q, Pan C, Xue Y, Fang Z, Zhang S, Wu B, Wu E. Plasmon Enhanced Second Harmonic Generation from ZnO Nanofilms on Vertical Au Nanorod Arrays. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2597. [PMID: 34685038 PMCID: PMC8539005 DOI: 10.3390/nano11102597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/18/2021] [Accepted: 09/30/2021] [Indexed: 11/16/2022]
Abstract
Vertically aligned gold nanorod arrays have attracted much attention for their fascinating optical properties. Different from longitudinal surface plasmon wavelength (LSPW) and edge-to-edge spacing of gold nanorods, the role of gold nanorod diameter in plasmonic enhancement ability of vertical gold nanorod arrays has rarely been explored. In this work, we selected gold nanorods with similar LSPW but two different diameters (22 and 41 nm), the optical properties of which are dominated by absorption and scattering cross sections, respectively. The vertically aligned arrays of these gold nanorods formed by evaporation self-assembly are coupled with nonlinear ZnO nanocrystal films spin-coated on their surfaces. It was found that the gold nanorod array with a larger diameter can enhance the second harmonic generation (SHG) of ZnO nanofilm by a factor of 27.0, while it is about 7.3 for the smaller gold nanorod array. Theoretical simulations indicate that such stronger enhancement of the larger vertical gold nanorod array compared with the smaller one is due to its stronger scattering ability and greater extent of near-field enhancement at SHG fundamental wavelength. Our work shows that the diameter of gold nanorods is also an important factor to be considered in realizing strong plasmon enhancement of vertically aligned gold nanorod arrays.
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Affiliation(s)
- Qiang Ma
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
| | - Chengda Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
| | - Yingxian Xue
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
| | - Zhiyun Fang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
| | - Shiyu Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
| | - Botao Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
| | - E Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; (Q.M.); (C.P.); (Y.X.); (Z.F.); (S.Z.); (E.W.)
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
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8
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Núñez-Leyva JM, Kolosovas-Machuca ES, Sánchez J, Guevara E, Cuadrado A, Alda J, González FJ. Computational and Experimental Analysis of Gold Nanorods in Terms of Their Morphology: Spectral Absorption and Local Field Enhancement. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1696. [PMID: 34203448 PMCID: PMC8308185 DOI: 10.3390/nano11071696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 01/04/2023]
Abstract
A nanoparticle's shape and size determine its optical properties. Nanorods are nanoparticles that have double absorption bands associated to surface plasmon oscillations along their two main axes. In this work, we analize the optical response of gold nanorods with numerical simulations and spectral absorption measurements to evaluate their local field enhancement-which is key for surface-enhanced Raman spectroscopic (SERS) applications. Our experimental results are in good agreement with finite element method (FEM) simulations for the spectral optical absorption of the nanoparticles. We also observed a strong dependence of the optical properties of gold nanorods on their geometrical dimension and shape. Our numerical simulations helped us reveal the importance of the nanorods' morphology generated during the synthesis stage in the evaluation of absorption and local field enhancement. The application of these gold nanorods in surface-enhancement Raman spectroscopy is analyzed numerically, and results in a 5.8×104 amplification factor when comparing the values obtained for the nanorod deposited on a dielectric substrate compared to the nanorod immersed in water.
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Affiliation(s)
- Juan Manuel Núñez-Leyva
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, 550 Sierra Leona Ave, San Luis Potosí 78210, Mexico; (J.M.N.-L.); (E.S.K.-M.); (J.S.); (E.G.); (F.J.G.)
- Doctorado Institucional en Ingeniería y Ciencia de Materiales (DICIM-UASLP), Universidad Autónoma de San Luis Potosí, 550 Sierra Leona Ave, San Luis Potosí 78210, Mexico
| | - Eleazar Samuel Kolosovas-Machuca
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, 550 Sierra Leona Ave, San Luis Potosí 78210, Mexico; (J.M.N.-L.); (E.S.K.-M.); (J.S.); (E.G.); (F.J.G.)
| | - John Sánchez
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, 550 Sierra Leona Ave, San Luis Potosí 78210, Mexico; (J.M.N.-L.); (E.S.K.-M.); (J.S.); (E.G.); (F.J.G.)
| | - Edgar Guevara
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, 550 Sierra Leona Ave, San Luis Potosí 78210, Mexico; (J.M.N.-L.); (E.S.K.-M.); (J.S.); (E.G.); (F.J.G.)
| | - Alexander Cuadrado
- Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/ Tulipán s/n, Móstoles, 28933 Madrid, Spain;
| | - Javier Alda
- Applied Optics Complutense Group, Faculty of Optics and Optometry, University Complutense of Madrid, 118 Arcos de Jalón Ave, 28037 Madrid, Spain
| | - Francisco Javier González
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, 550 Sierra Leona Ave, San Luis Potosí 78210, Mexico; (J.M.N.-L.); (E.S.K.-M.); (J.S.); (E.G.); (F.J.G.)
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9
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Albarghouthi N, MacMillan P, Brosseau CL. Optimization of gold nanorod arrays for surface enhanced Raman spectroscopy (SERS) detection of atrazine. Analyst 2021; 146:2037-2047. [PMID: 33533352 DOI: 10.1039/d0an02215b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recently, there has been increasing concern over the widespread use of the herbicide atrazine which has been reported to have problematic side effects on local ecosystems. This has highlighted the need for rapid and accurate point-of-need assessment tools for analytical determination of herbicides in ground and surface waters. Surface enhanced Raman spectroscopy (SERS) is a sensitive vibrational spectroscopy technique which has recently been employed for the analysis of a variety of analytes in water, ranging from pharmaceuticals to pesticides. In this work, SERS sensors constructed using gold nanorod (AuNR) arrays are optimized and then utilized for the rapid and sensitive detection of atrazine. In this study, the effect of relative humidity on the self-assembly of gold nanorods into arrays was explored, and the SERS performance was assessed using para-aminothiophenol as a SERS probe. Once the SERS performance of the substrates was deemed optimal, the detection of atrazine was highlighted. This work represents the first time that relative humidity has been explored as an optimization strategy for controlled alignment of gold nanorods for SERS analysis of atrazine.
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Affiliation(s)
- Najwan Albarghouthi
- Department of Chemistry, Saint Mary's University, 923 Robie St., Halifax, Nova Scotia, Canada.
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10
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Peng W, Liao Q, Song H. A nanograting-based flexible and stretchable waveguide for tactile sensing. NANOSCALE RESEARCH LETTERS 2021; 16:23. [PMID: 33547515 PMCID: PMC7865040 DOI: 10.1186/s11671-021-03488-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/21/2021] [Indexed: 05/30/2023]
Abstract
Based on the related characteristics of optical waveguide and flexible optical materials, a flexible and stretchable optical waveguide structure oriented to tactile perception is proposed. The sensing principle of optical waveguide is based on mechanical deformation caused by output light loss. It overcomes the shortcomings of traditional optical waveguide devices, which are unable to conform to irregular surface. The flexible and stretchable optical waveguide is fabricated with nanoreplica molding method, and it has been applied to the measurement of pressure and strain in the field of tactile sensing. The flexible and stretchable optical waveguide had a strain detection range of 0 to 12.5%, and the external force detection range is from 0 to 23 × 10-3 N.
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Affiliation(s)
- Wang Peng
- College of Engineering, Huazhong Agricultural University, Wuhan, 430070, China.
- School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Qingxi Liao
- College of Engineering, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Han Song
- School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan, 430070, China
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11
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Dong J, Cao Y, Han Q, Gao W, Li T, Qi J. Nanoscale flexible Ag grating/AuNPs self-assembly hybrid for ultra-sensitive sensors. NANOTECHNOLOGY 2021; 32:155603. [PMID: 33511966 DOI: 10.1088/1361-6528/abd7b2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this paper, Au nanoparticles (AuNPs) are prepared using wet chemical reduction transfer of dense AuNPs film by self-assembly to the surface of Ag grating, which is inverted from the inner DVD after evaporation. The Ag grating/AuNPs self-assembly hybrid substrate commonly used in surface-enhanced Raman scattering (SERS) research is produced. The coupling effect between AuNP-AuNP and AuNPs-Ag slugs can evidently enhance the local electric field. Experimental results show that the hybrid SERS substrate can detect 10-9 M Rh6G, and the enhancement factor reaches 4.4 × 105. This small, cheap hybrid substrate has enormous potential in the field of SERS sensing.
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Affiliation(s)
- Jun Dong
- School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an, 710121, People's Republic of China
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12
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Liu M. Growth of Nanostructured Silver Flowers by Metal-Mediated Catalysis for Surface-Enhanced Raman Spectroscopy Application. ACS OMEGA 2020; 5:32655-32659. [PMID: 33376902 PMCID: PMC7758958 DOI: 10.1021/acsomega.0c05021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 05/13/2023]
Abstract
Metallic flowers with nanoscale surface roughness can provide a platform for highly sensitive and reproductive surface-enhanced Raman spectroscopy (SERS). Here, we present a method to grow a nanostructured silver flower (NSF) at the apex of a plasmonic tip based on metal-mediated catalysis, where the NSF was rapidly generated in no more than 1 min. The NSF was used as the SERS substrate under linear polarization beam (LPB) excitation to achieve a 10-9 M detection sensitivity for the malachite green analyte. The reproducibility for SERS is examined to have been guaranteed by comparing Raman intensity enhanced by different NSFs. Compared with the LPB, the azimuthal vector beam (AVB) excitation can further improve the SERS activity of the NSF, which is consistent with the simulation result that the gap mode can be effectively generated between two adjacent Ag nanoparticles (NPs) and between the NPs and the Ag pyramids on the surface of the NSF under AVB illumination. This work makes it promising for plasmonic tip-mediated catalysis to be applied in nanofabrication, the products of which can be further exploited in nanostructure-based ultrasensitive detection.
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Affiliation(s)
- Min Liu
- School
of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
- MOE
Key Laboratory of Material Physics and Chemistry under Extraordinary
Conditions and Shaanxi Key Laboratory of Optical Information Technology,
School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710072, China
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13
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Dong J, Cao Y, Han Q, Wang Y, Qi M, Zhang W, Qiao L, Qi J, Gao W. Plasmon-exciton coupling for nanophotonic sensing on chip. OPTICS EXPRESS 2020; 28:20817-20829. [PMID: 32680134 DOI: 10.1364/oe.387867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
The monolayer graphene-noble metallic nanostructure hybrid system with excellent optical characteristic, which is deserved pay attentions in the study of surface-enhanced Raman scattering spectroscopy. In this work, a hybrid sandwich structure is designed to transfer single-layer graphene to the surface of discs substrate covered by silver film and assembly of the dense Au nanoparticles (AuNPs). Blu-ray disc has a cycle density of approximately 5.7 times that of DVD-R due to the different storage capacities of these optical discs. In the research, enhancement effects have been explored for two different periodic grating structures. Compared to spectra of Si/G structure, Graphene Raman spectra from Blu-grating/AuNPs/G structure and Blu-grating/G/AuNPs enhancement multiples at the 2D peak position possesses different Raman responses of 1.09 and 2.51 times, respectively. The sandwich hybrid structure of Ag grating/graphene/AuNPs obtains a Raman enhancement factor (EF) of 6.2×108 for Rhodamine 6G and surface-enhanced Raman Scattering(SERS) detection limit of 0.1 nM. These findings can be attributed to the electric field enhancement of the hybrid structure and the chemical enhancement of graphene. This study provides a new approach for SERS detection and offers a new technique for designing SERS sensors with grapheme-plasmon hybrid structures.
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14
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Wang Y, Dong J, Wang Z, Zhou S, Wang Q, Han Q, Gao W, Ren K, Qi J. Strong circular dichroism enhancement by plasmonic coupling between graphene and h-shaped chiral nanostructure. OPTICS EXPRESS 2019; 27:33869-33879. [PMID: 31878446 DOI: 10.1364/oe.27.033869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Circular dichroism (CD) is useful in polarization conversion, negative refraction chemical analysis, and bio-sensing. To achieve strong CD signals, researchers constantly break the symmetry of nanostructures. However, how to further enhance the CD based on a new mechanism has become a new challenge in this field. In this work, a hybrid plasmonic chiral system composed of an array of graphene ribbons (GRs) over h-shaped sliver chiral nanostructures (HSCNs) is theoretically investigated. Results demonstrate that the plasmonic coupling between HSCNs and GRs results in different enhanced absorptions for different circularly polarized lights. The absorbance of right circularly polarized light is enhanced to perfect absorption; the absorption of left circularly polarized light is enhanced weakly. It leads to the CD effect of HSCNs@GRs approaching 88%. The loss distributions of HSCNs and HSCNs@GRs reveal that the absorption is enhanced and transferred from HSCNs to GRs. Moreover, the current distributions of HSCNs@GRs are simplified to equivalent LC resonant circuits, which can qualitatively explain the change of CD signals by tuning geometrical parameters of HSCNs@GRs. The findings of this work provide a new method of enhancing chirality and benefit the design of graphene-based chiral optoelectronic devices.
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