1
|
Czaja M, Chachaj-Brekiesz A, Skirlińska-Nosek K, Szajna K, Sofińska K, Lupa D, Kobierski J, Wnętrzak A, Szymoński M, Lipiec E. Fabrication of plasmonic probes for reproducible nanospectroscopic investigation of lipid monolayers - The electrochemical etching with DC-pulsed voltage. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 316:124323. [PMID: 38692104 DOI: 10.1016/j.saa.2024.124323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/12/2024] [Accepted: 04/21/2024] [Indexed: 05/03/2024]
Abstract
Tip-enhanced Raman spectroscopy (TERS) is a label-free analytical technique that characterizes molecular systems, potentially even with a nanometric resolution. In principle, the metallic plasmonic probe is illuminated with a laser beam generating the localized surface plasmons, which induce a strong local electric field enhancement in close proximity to the probe. Such field enhancement improves the Raman scattering cross-section from the sample volume localized near the probe apex. TERS provides a high spatial resolution and a great sensitivity, however, it is rather rarely used due to technical limitations causing unstable enhancement and the relative lack of data reproducibility. Despite many scientific efforts for the fabrication of effective TER probes providing robust TER enhancement still requires further investigations. In this work, we explore new possibilities based on preparation of scanning tunnelling microscopy (STM) plasmonic probes, since by nature of the tunnelling effect, they potentially could offer a very high spatial resolution in STM guided TERS experiments. Here we compare two methods of STM-TERS probe preparation for effective spectra acquisition. Our results strongly indicate that an application of square pulse voltage upon the etching procedure significantly improves the quality of the TER data over those obtained with a constant voltage one. To demonstrate the efficiency of our probes we present the results of hyperspectral TER mapping of the 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) monolayer deposited on an ultra-pure and atomically flat gold substrate.
Collapse
Affiliation(s)
- Michał Czaja
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland; Jagiellonian University, Doctoral School of Exact and Natural Sciences, Kraków 30-387, Poland
| | - Anna Chachaj-Brekiesz
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Kraków 30-387, Poland
| | - Katarzyna Skirlińska-Nosek
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland; Jagiellonian University, Doctoral School of Exact and Natural Sciences, Kraków 30-387, Poland
| | - Konrad Szajna
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland
| | - Kamila Sofińska
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland
| | - Dawid Lupa
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland
| | - Jan Kobierski
- Jagiellonian University Medical College, Faculty of Pharmacy, Department of Pharmaceutical Biophysics, Medyczna 9, Kraków 30-688, Poland
| | - Anita Wnętrzak
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Kraków 30-387, Poland
| | - Marek Szymoński
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland
| | - Ewelina Lipiec
- Jagiellonian University, Faculty of Physics, Astronomy, and Applied Computer Science, M. Smoluchowski Institute of Physics, Łojasiewicza 11, Kraków 30-348, Poland.
| |
Collapse
|
2
|
Meng B, Xie Y, Chen L, Wang H, Li M, Dong Z. Apex-Confined Plasmonic Tip for High Resolution Tip-Enhanced Raman Spectroscopic Imaging of Carbon Nanotubes. ACS APPLIED MATERIALS & INTERFACES 2023; 15:16984-16990. [PMID: 36946568 DOI: 10.1021/acsami.2c22624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
This paper reports a handy technical scheme to decorate atomic force microscopy (AFM) tips toward tip-enhanced Raman spectroscopy (TERS) applications. The major attraction of these homemade tips lies in that silver decoration can be confined at the apex of commercial tips by the means of an AFM-controlled electrochemical reaction. The reduction of Ag+ occurs in a highly sealed environment to secure the metal coating efficiency. Key factors include silver nitrate solution to provide Ag+, ambient relative humidity and temperature in a humidity cell, electric potential bias, and tip-surface distance. Subsequently, these silver-coated tips are evaluated for TERS measurement of carbon nanotubes (CNTs) so that both morphological and chemical characteristics of CNTs are concurrently obtained. The Raman spectra reveal that our plasmonic tip competently possesses an ∼30-fold local field signal increase and the corresponding TERS image laterally resolves at the single-pixel level.
Collapse
Affiliation(s)
- Bin Meng
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Yong Xie
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Le Chen
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Haitao Wang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Ming Li
- School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Zhuxin Dong
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| |
Collapse
|
3
|
Shi H, Zhu X, Zhang S, Wen G, Zheng M, Duan H. Plasmonic metal nanostructures with extremely small features: new effects, fabrication and applications. NANOSCALE ADVANCES 2021; 3:4349-4369. [PMID: 36133477 PMCID: PMC9417648 DOI: 10.1039/d1na00237f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/14/2021] [Indexed: 06/14/2023]
Abstract
Surface plasmons in metals promise many fascinating properties and applications in optics, sensing, photonics and nonlinear fields. Plasmonic nanostructures with extremely small features especially demonstrate amazing new effects as the feature sizes scale down to the sub-nanometer scale, such as quantum size effects, quantum tunneling, spill-out of electrons and nonlocal states etc. The unusual physical, optical and photo-electronic properties observed in metallic structures with extreme feature sizes enable their unique applications in electromagnetic field focusing, spectra enhancing, imaging, quantum photonics, etc. In this review, we focus on the new effects, fabrication and applications of plasmonic metal nanostructures with extremely small features. For simplicity and consistency, we will focus our topic on the plasmonic metal nanostructures with feature sizes of sub-nanometers. Subsequently, we discussed four main and typical plasmonic metal nanostructures with extremely small features, including: (1) ultra-sharp plasmonic metal nanotips; (2) ultra-thin plasmonic metal films; (3) ultra-small plasmonic metal particles and (4) ultra-small plasmonic metal nanogaps. Additionally, the corresponding fascinating new effects (quantum nonlinear, non-locality, quantum size effect and quantum tunneling), applications (spectral enhancement, high-order harmonic wave generation, sensing and terahertz wave detection) and reliable fabrication methods will also be discussed. We end the discussion with a brief summary and outlook of the main challenges and possible breakthroughs in the field. We hope our discussion can inspire the broader design, fabrication and application of plasmonic metal nanostructures with extremely small feature sizes in the future.
Collapse
Affiliation(s)
- Huimin Shi
- Center for Research on Leading Technology of Special Equipment, School of Mechanical and Electrical Engineering, Guangzhou University Guangzhou 510006 China
| | - Xupeng Zhu
- School of Physics Science and Technology, Lingnan Normal University Zhanjiang 524048 China
| | - Shi Zhang
- College of Mechanical and Vehicle Engineering, Hunan University Changsha 410082 China
| | - Guilin Wen
- Center for Research on Leading Technology of Special Equipment, School of Mechanical and Electrical Engineering, Guangzhou University Guangzhou 510006 China
| | | | - Huigao Duan
- College of Mechanical and Vehicle Engineering, Hunan University Changsha 410082 China
| |
Collapse
|
4
|
Kharintsev SS, Kharitonov AV, Alekseev AM, Kazarian SG. Superresolution stimulated Raman scattering microscopy using 2-ENZ nano-composites. NANOSCALE 2019; 11:7710-7719. [PMID: 30946390 DOI: 10.1039/c8nr09890e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Superlensing plays a crucial role in near- and far-field optical imaging with sub-wavelength resolution. One of the ways to expand optical bandwidth is surface plasmon resonances in layered metal-dielectric nanostructures. These resonances are commonly excited at a tunable single frequency. In this study, we propose the concept of a multimode far-field superlens made of a titanium oxynitride (TiON) thin film, that is a disordered metal-dielectric refractory nano-composite. These films exhibit a double epsilon-near-zero (2-ENZ) behavior near the percolation threshold and, therefore, favor super-coupling the incident laser light to surface plasmon resonances, not using such couplers as a prism, a grating, etc. We experimentally observe stimulated Raman gain emission from nano-structured TiON thin films exposed to low-power continuous-wave laser light. It is shown that superresolution of <λ/80 (near-field) and <λ/8 (far-field) is achieved due to both the enhanced third-order optical nonlinearity and the multiplicative nature of four-wave mixing. The multimode tunable far-field superlens will impact emerging diffraction-free far-field optical microscopy, random Raman lasing on meta-atoms and broadband thermophotovoltaics.
Collapse
Affiliation(s)
- Sergey S Kharintsev
- Department of Optics and Nanophotonics, Institute of Physics, Kazan Federal University, Kremlevskaya, 16, Kazan, 420008, Russia.
| | | | | | | |
Collapse
|
5
|
Kharintsev SS, Gazizov AR, Salakhov MK, Kazarian SG. Near-field depolarization of tip-enhanced Raman scattering by single azo-chromophores. Phys Chem Chem Phys 2018; 20:24088-24098. [PMID: 30204183 DOI: 10.1039/c8cp04887h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The intrinsic symmetry and orientation of single molecules play a crucial role in enhanced optical spectroscopy and nanoscopic imaging. Unlike bulk materials, in which all molecular orientations are unavoidably averaged in the far-field, intensities of vibrational modes in tip-enhanced Raman scattering (TERS) depend greatly on the polarization direction of near-field light. It means that a near-field Raman "dichroism" becomes possible for anisotropic single molecules. Quantitative evaluation of the molecular orientation gets complicated by the depolarization of TERS intensities. Clearly, the depolarization effect is enhanced with an optical antenna and/or a substrate due to their anisotropic origin. In this study, we provide theoretical and experimental insights into Raman tensors of a single azobenzene chromophore, a Disperse Orange 3 (DO3) molecule, supported with a glass base. It is shown that the Raman intensities of the spectral bands corresponding to symmetric and antisymmetric vibrations of the DO3 molecule, for example, -NO2 and -NH2 moieties, behave differently on the nanoscale. In particular, three-dimensional far- and near-field Raman diagrams indicate that antisymmetric vibrations become highly depolarized, whereas symmetric vibrations remain unchangeable but intensities of their spectral bands are enhanced. Here, we introduce a near-field depolarization factor defined as a normalized discrepancy of longitudinal and transverse TERS signals. We believe that our first steps will ultimately lead to advanced facilities of TERS spectroscopy and nanoscopy, related to the orientation of anisotropic single molecules and their symmetries.
Collapse
Affiliation(s)
- Sergey S Kharintsev
- Department of Optics and Nanophotonics, Institute of Physics, Kazan Federal University, Kremlevskaya, 16, Kazan, 420008, Russia.
| | | | | | | |
Collapse
|
6
|
Deckert-Gaudig T, Taguchi A, Kawata S, Deckert V. Tip-enhanced Raman spectroscopy - from early developments to recent advances. Chem Soc Rev 2018. [PMID: 28640306 DOI: 10.1039/c7cs00209b] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An analytical technique operating at the nanoscale must be flexible regarding variable experimental conditions while ideally also being highly specific, extremely sensitive, and spatially confined. In this respect, tip-enhanced Raman scattering (TERS) has been demonstrated to be ideally suited to, e.g., elucidating chemical reaction mechanisms, determining the distribution of components and identifying and localizing specific molecular structures at the nanometre scale. TERS combines the specificity of Raman spectroscopy with the high spatial resolution of scanning probe microscopies by utilizing plasmonic nanostructures to confine the incident electromagnetic field and increase it by many orders of magnitude. Consequently, molecular structure information in the optical near field that is inaccessible to other optical microscopy methods can be obtained. In this general review, the development of this still-young technique, from early experiments to recent achievements concerning inorganic, organic, and biological materials, is addressed. Accordingly, the technical developments necessary for stable and reliable AFM- and STM-based TERS experiments, together with the specific properties of the instruments under different conditions, are reviewed. The review also highlights selected experiments illustrating the capabilities of this emerging technique, the number of users of which has steadily increased since its inception in 2000. Finally, an assessment of the frontiers and new concepts of TERS, which aim towards rendering it a general and widely applicable technique that combines the highest possible lateral resolution and extreme sensitivity, is provided.
Collapse
|
7
|
Affiliation(s)
- Lifu Xiao
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Zachary D Schultz
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| |
Collapse
|
8
|
Kharintsev SS, Fishman AI, Saikin SK, Kazarian SG. Near-field Raman dichroism of azo-polymers exposed to nanoscale dc electrical and optical poling. NANOSCALE 2016; 8:19867-19875. [PMID: 27878200 DOI: 10.1039/c6nr07508h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Azobenzene-functionalized polymer films are functional materials, where the (planar vs. homeotropic) orientation of azo-dyes can be used for storing data. In order to characterize the nanoscale 3D orientation of the pigments in sub-10 nm thick polymer films we use two complementary techniques: polarization-controlled tip-enhanced Raman scattering (TERS) microscopy and contact scanning capacity microscopy. We demonstrate that the homeotropic and planar orientations of the azo-dyes are produced by applying a local dc electrical field and a resonant longitudinal optical near-field, respectively. For a non-destructive probe of the azo-dye orientation we apply a non-resonant optical near-field and compare the intensities of the Raman-active vibrational modes. We show that near-field Raman dichroism, a characteristic similar to the absorption dichroism used in far-field optics, can be a quantitative indicator of the 3D molecular orientation of the azo-dye at the nanoscale. This study directly benefits the further development of photochromic near-field optical memory that can lead to ultrahigh density information storage.
Collapse
Affiliation(s)
- Sergey S Kharintsev
- Department of Optics and Nanophotonics, Institute of Physics, Kazan Federal University, Kremlevskaya, 16, Kazan, 420008, Russia. and Institute of Perspective Technologies, Tatarstan Academy of Sciences, Baumana, 20, Kazan, 420111, Russia
| | - Alexandr I Fishman
- Department of Optics and Nanophotonics, Institute of Physics, Kazan Federal University, Kremlevskaya, 16, Kazan, 420008, Russia.
| | - Semion K Saikin
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA and Department of Theoretical Physics, Institute of Physics, Kazan Federal University, Kremlevskaya, 16, Kazan, 420008, Russia
| | - Sergei G Kazarian
- Department of Chemical Engineering, Imperial College, London, SW7 2AZ, UK
| |
Collapse
|