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Kato R, Taguchi K, Yadav R, Umakoshi T, Verma P. One-side metal-coated pyramidal cantilever tips for highly reproducible tip-enhanced Raman spectroscopy. NANOTECHNOLOGY 2020; 31:335207. [PMID: 32375128 DOI: 10.1088/1361-6528/ab90b6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Tip-enhanced Raman spectroscopy (TERS) has been recognized as a useful tool for nanoscale chemical analysis, and it can further reach down to the sub-nanometer scale in the gap-mode configuration. Using an atomic force microscopy (AFM) in gap-mode TERS for position control of a metallic tip, a unique and correlative analysis can be even realized at the single molecule level. However, one of crucial issues in AFM-based gap-mode TERS is the fabrication of reliable and reproducible cantilver metallic tips. Here, we propose a simple, cost-effective fabrication method of metal-coated tips for AFM-based gap-mode TERS by means of the physical vapor deposition technique in a reproducible way. Our plamonic tips have extremely smooth silver layers on one side of the pyramidal tip, which is totally different from the regular metallic tips that hold granular metallic structures randomly arranged on their bodies. Importantly, all fabricated tips exhibited a reasonably high enhancement factor of more than 104, which indicates that the reproducibility of our plasmonic tip is virtually 100% in the gap-mode configuration. The excellent reproducibility of gap-mode TERS measurement holds great promise for rendering AFM-based TERS as a powerful analytical technique in a broad range of fields.
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Affiliation(s)
- Ryo Kato
- Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan
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2
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Kumar N, Wondergem CS, Wain AJ, Weckhuysen BM. In Situ Nanoscale Investigation of Catalytic Reactions in the Liquid Phase Using Zirconia-Protected Tip-Enhanced Raman Spectroscopy Probes. J Phys Chem Lett 2019; 10:1669-1675. [PMID: 30916970 PMCID: PMC6477806 DOI: 10.1021/acs.jpclett.8b02496] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Tip-enhanced Raman spectroscopy (TERS) is a promising technique that enables nondestructive and label-free topographical and chemical imaging at the nanoscale. However, its scope for in situ characterization of catalytic reactions in the liquid phase has remained limited due to the lack of durable and chemically inert plasmonically active TERS probes. Herein, we present novel zirconia-protected TERS probes with 3 orders of magnitude increase in lifetime under ambient conditions compared to unprotected silver-coated probes, together with high stability in liquid media. Employing the plasmon-assisted oxidation of p-aminothiophenol as a model reaction, we demonstrate that the highly robust, durable, and chemically inert zirconia-protected TERS probes can be successfully used for nanoscale spatially resolved characterization of a photocatalytic reaction within an aqueous environment. The reported improved lifetime and stability of probes in a liquid environment extend the potential scope of TERS as a nanoanalytical tool not only to heterogeneous catalysis but also to a range of scientific disciplines in which dynamic solid-liquid interfaces play a defining role.
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Affiliation(s)
- Naresh Kumar
- Inorganic
Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
- National
Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - Caterina S. Wondergem
- Inorganic
Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Andrew J. Wain
- National
Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - Bert M. Weckhuysen
- Inorganic
Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
- E-mail:
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Kumar N, Weckhuysen BM, Wain AJ, Pollard AJ. Nanoscale chemical imaging using tip-enhanced Raman spectroscopy. Nat Protoc 2019; 14:1169-1193. [PMID: 30911174 DOI: 10.1038/s41596-019-0132-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/09/2019] [Indexed: 11/09/2022]
Abstract
Confocal and surface-enhanced Raman spectroscopy (SERS) are powerful techniques for molecular characterization; however, they suffer from the drawback of diffraction-limited spatial resolution. Tip-enhanced Raman spectroscopy (TERS) overcomes this limitation and provides chemical information at length scales in the tens of nanometers. In contrast to alternative approaches to nanoscale chemical analysis, TERS is label free, is non-destructive, and can be performed in both air and liquid environments, allowing its use in a diverse range of applications. Atomic force microscopy (AFM)-based TERS is especially versatile, as it can be applied to a broad range of samples on various substrates. Despite its advantages, widespread uptake of this technique for nanoscale chemical imaging has been inhibited by various experimental challenges, such as limited lifetime, and the low stability and yield of TERS probes. This protocol details procedures that will enable researchers to reliably perform TERS imaging using a transmission-mode AFM-TERS configuration on both biological and non-biological samples. The procedure consists of four stages: (i) preparation of plasmonically active TERS probes; (ii) alignment of the TERS system; (iii) experimental procedures for nanoscale imaging using TERS; and (iv) TERS data processing. We provide procedures and example data for a range of different sample types, including polymer thin films, self-assembled monolayers (SAMs) of organic molecules, photocatalyst surfaces, small molecules within biological cells, single-layer graphene and single-walled carbon nanotubes in both air and water. With this protocol, TERS probes can be prepared within ~23 h, and each subsequent TERS experimental procedure requires 3-5 h.
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Affiliation(s)
- Naresh Kumar
- National Physical Laboratory, Teddington, UK.,Inorganic Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, the Netherlands
| | - Bert M Weckhuysen
- Inorganic Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, the Netherlands
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Lin D, Lin YC, Yang SW, Zhou L, Leong WK, Feng SY, Kong KV. Organometallic-Constructed Tip-Based Dual Chemical Sensing by Tip-Enhanced Raman Spectroscopy for Diabetes Detection. ACS APPLIED MATERIALS & INTERFACES 2018; 10:41902-41908. [PMID: 30387600 DOI: 10.1021/acsami.8b11950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Tip-enhanced Raman spectroscopy (TERS) is capable of probing specific molecular information with high sensitivity, but dual chemical sensing remains a challenge. Another major hindrance to TERS chemical detection in biosamples such as blood is the interference from the strong absorptions of biomolecules. Herein, we report the preparation of an organometallic-conjugated TERS tip. We demonstrate that organometallic chemistry can be perfectly coupled with TERS for dual-molecule sensing. The unique Raman signals generated by the organometallic compound circumvent signal interference from the biomolecules in blood, allowing the rapid analysis of two important molecules (glucose and thiol) in ultralow volume (50 nL) samples. This enabled a correlation between the thiol and glucose levels in the blood of nondiabetic and diabetic patients to be drawn.
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Affiliation(s)
- Duo Lin
- Key Laboratory of OptoElectronic Science and Technology for Medicine, Ministry of Education, Fujian Provincial Key Laboratory for Photonics Technology , Fujian Normal University , Fuzhou 350007 , China
- College of Integrated Traditional Chinese and Western Medicine , Fujian University of Traditional Chinese Medicine , Fuzhou 350122 , China
| | - Yi-Cheng Lin
- Department of Chemistry , National Taiwan University , Taipei 10617 , Taiwan
| | - Shang-Wei Yang
- Department of Chemistry , National Taiwan University , Taipei 10617 , Taiwan
| | - Lan Zhou
- Department of Urology, Shanghai East Hospital , Tongji University School of Medicine , Shanghai 200000 , China
| | - Weng Kee Leong
- Division of Chemistry & Biological Chemistry , Nanyang Technological University , 639798 , Singapore
| | - Shang-Yuan Feng
- Key Laboratory of OptoElectronic Science and Technology for Medicine, Ministry of Education, Fujian Provincial Key Laboratory for Photonics Technology , Fujian Normal University , Fuzhou 350007 , China
| | - Kien Voon Kong
- Department of Chemistry , National Taiwan University , Taipei 10617 , Taiwan
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Auner GW, Koya SK, Huang C, Broadbent B, Trexler M, Auner Z, Elias A, Mehne KC, Brusatori MA. Applications of Raman spectroscopy in cancer diagnosis. Cancer Metastasis Rev 2018; 37:691-717. [PMID: 30569241 PMCID: PMC6514064 DOI: 10.1007/s10555-018-9770-9] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Novel approaches toward understanding the evolution of disease can lead to the discovery of biomarkers that will enable better management of disease progression and improve prognostic evaluation. Raman spectroscopy is a promising investigative and diagnostic tool that can assist in uncovering the molecular basis of disease and provide objective, quantifiable molecular information for diagnosis and treatment evaluation. This technique probes molecular vibrations/rotations associated with chemical bonds in a sample to obtain information on molecular structure, composition, and intermolecular interactions. Raman scattering occurs when light interacts with a molecular vibration/rotation and a change in polarizability takes place during molecular motion. This results in light being scattered at an optical frequency shifted (up or down) from the incident light. By monitoring the intensity profile of the inelastically scattered light as a function of frequency, the unique spectroscopic fingerprint of a tissue sample is obtained. Since each sample has a unique composition, the spectroscopic profile arising from Raman-active functional groups of nucleic acids, proteins, lipids, and carbohydrates allows for the evaluation, characterization, and discrimination of tissue type. This review provides an overview of the theory of Raman spectroscopy, instrumentation used for measurement, and variation of Raman spectroscopic techniques for clinical applications in cancer, including detection of brain, ovarian, breast, prostate, and pancreatic cancers and circulating tumor cells.
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Affiliation(s)
- Gregory W Auner
- Michael and Marian Ilitch Department of Surgery, School of Medicine, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA.
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA.
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA.
- Henry Ford Health Systems, Detroit Institute of Ophthalmology, Grosse Pointe Park, MI, 48230, USA.
| | - S Kiran Koya
- Michael and Marian Ilitch Department of Surgery, School of Medicine, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
| | - Changhe Huang
- Michael and Marian Ilitch Department of Surgery, School of Medicine, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
| | - Brandy Broadbent
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
| | - Micaela Trexler
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
| | - Zachary Auner
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
- Department of Physics & Astronomy, Wayne State University, Detroit, MI, 48202, USA
| | - Angela Elias
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
| | - Katlyn Curtin Mehne
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
| | - Michelle A Brusatori
- Michael and Marian Ilitch Department of Surgery, School of Medicine, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Department of Biomedical Engineering, College of Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI, 48202, USA
- Smart Sensors and Integrated Microsystems Program, Wayne State University, Detroit, MI, 48202, USA
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Hermann RJ, Gordon MJ. Nanoscale Optical Microscopy and Spectroscopy Using Near-Field Probes. Annu Rev Chem Biomol Eng 2018; 9:365-387. [DOI: 10.1146/annurev-chembioeng-060817-084150] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Light-matter interactions can provide a wealth of detailed information about the structural, electronic, optical, and chemical properties of materials through various excitation and scattering processes that occur over different length, energy, and timescales. Unfortunately, the wavelike nature of light limits the achievable spatial resolution for interrogation and imaging of materials to roughly λ/2 because of diffraction. Scanning near-field optical microscopy (SNOM) breaks this diffraction limit by coupling light to nanostructures that are specifically designed to manipulate, enhance, and/or extract optical signals from very small regions of space. Progress in the SNOM field over the past 30 years has led to the development of many methods to optically characterize materials at lateral spatial resolutions well below 100 nm. We review these exciting developments and demonstrate how SNOM is truly extending optical imaging and spectroscopy to the nanoscale.
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Affiliation(s)
- Richard J. Hermann
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA;,
| | - Michael J. Gordon
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA;,
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Kumar N, Su W, Veselý M, Weckhuysen BM, Pollard AJ, Wain AJ. Nanoscale chemical imaging of solid-liquid interfaces using tip-enhanced Raman spectroscopy. NANOSCALE 2018; 10:1815-1824. [PMID: 29308817 DOI: 10.1039/c7nr08257f] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Tip-enhanced Raman spectroscopy (TERS) is a powerful tool for non-destructive and label-free surface molecular mapping at the nanoscale. However, to date nanoscale resolution chemical imaging in a liquid environment has not been possible, in part due to the lack of robust TERS probes that are stable when immersed in a liquid. In this work, we have addressed this challenge by developing plasmonically-active TERS probes with a multilayer metal coating structure that can be successfully used within a liquid environment. Using these novel TERS probes, we have compared the plasmonic enhancement of TERS signals in air and water environments for both gap mode and non-gap mode configurations and show that in both cases the plasmonic enhancement decreases in water. To better understand the signal attenuation in water, we have performed numerical simulations that revealed a negative correlation between the electric field enhancement at the TERS probe-apex and the refractive index of the surrounding medium. Finally, using these robust probes we demonstrate TERS imaging with nanoscale spatial resolution in a water environment for the first time by employing single-wall carbon nanotubes as a model sample. Our findings are expected to broaden the scope of TERS to a range of scientific disciplines in which nanostructured solid-liquid interfaces play a key role.
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Affiliation(s)
- Naresh Kumar
- National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK.
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