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Fiederling K, Abasifard M, Richter M, Deckert V, Kupfer S, Gräfe S. A Full Quantum Mechanical Approach Assessing the Chemical and Electromagnetic Effect in TERS. ACS NANO 2023. [PMID: 37429582 PMCID: PMC10373516 DOI: 10.1021/acsnano.2c11855] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Tip-enhanced Raman spectroscopy (TERS) is a valuable method for surface analysis with nanometer to angstrom-scale resolution; however, the accurate simulation of particular TERS signals remains a computational challenge. We approach this challenge by combining the two main contributors to plasmon-enhanced Raman spectroscopy and to the high resolution in TERS, in particular, the electromagnetic and the chemical effect, into one quantum mechanical simulation. The electromagnetic effect describes the sample's interaction with the strong, highly localized, and inhomogeneous electric fields associated with the plasmonic tip and is typically the thematic focus for most mechanistic studies. On the other hand, the chemical effect covers the different responses to the extremely close-range and highly position-sensitive chemical interaction between the apex tip atom(s) and the sample, and, as we could show in previous works, plays an often underestimated role. Starting from a (time-dependent) density functional theory description of the chemical model system, comprised of a tin(II) phthalocyanine sample molecule and a single silver atom as the tip, we introduce the electromagnetic effect through a series of static point charges that recreate the electric field in the vicinity of the plasmonic Ag nanoparticle. By scanning the tip over the molecule along a 3D grid, we can investigate the system's Raman response on each position for nonresonant and resonant illumination. Simulating both effects on their own already hints at the achievable signal enhancement and resolution, but the combination of both creates even stronger evidence that TERS is capable of resolving submolecular features.
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Affiliation(s)
- Kevin Fiederling
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Mostafa Abasifard
- Institute of Applied Physics and Abbe Center of Photonics, Friedrich Schiller University Jena, Albert-Einstein-Str. 15, 07745 Jena, Germany
| | - Martin Richter
- DS Deutschland GmbH, Am Kabellager 11-13, 51063 Cologne, Germany
| | - Volker Deckert
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07743 Jena, Germany
| | - Stephan Kupfer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Stefanie Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
- Institute of Applied Physics and Abbe Center of Photonics, Friedrich Schiller University Jena, Albert-Einstein-Str. 15, 07745 Jena, Germany
- Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein-Str. 7, 07745 Jena, Germany
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Sinha B, Goswami T, Paul S, Misra A. Spectral tuning of 11-cis retinal in conjugation with Au14 cluster and concomitant effect on isomerization: A theoretical outlook. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021. [DOI: 10.1016/j.jpap.2021.100051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Fiederling K, Kupfer S, Gräfe S. Are charged tips driving TERS-resolution? A full quantum chemical approach. J Chem Phys 2021; 154:034106. [DOI: 10.1063/5.0031763] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- K. Fiederling
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - S. Kupfer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - S. Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
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Fiederling K, Abasifard M, Richter M, Deckert V, Gräfe S, Kupfer S. The chemical effect goes resonant - a full quantum mechanical approach on TERS. NANOSCALE 2020; 12:6346-6359. [PMID: 32134418 DOI: 10.1039/c9nr09814c] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Lately, experimental evidence of unexpectedly extremely high spatial resolution of tip-enhanced Raman scattering (TERS) has been demonstrated. Theoretically, two different contributions are discussed: an electromagnetic effect, leading to a spatially confined near field due to plasmonic excitations; and the so-called chemical effect originating from the locally modified electronic structure of the molecule due to the close proximity of the plasmonic system. Most of the theoretical efforts have concentrated on the electromagnetic contribution or the chemical effect in case of non-resonant excitation. In this work, we present a fully quantum mechanical description including non-resonant and resonant chemical contributions as well as charge-transfer phenomena of these molecular-plasmonic hybrid systems at the density functional and the time-dependent density functional level of theory. We consider a surface-immobilized tin(ii) phthalocyanine molecule as the molecular system, which is minutely scanned by a plasmonic tip, modeled by a single silver atom. These different relative positions of the Ag atom to the molecule lead to pronounced alterations of the Raman spectra. These Raman spectra vary substantially, both in peak positions and several orders of magnitude in the intensity patterns under non-resonant and resonant conditions, and also, depending on, which electronic states are addressed. Our computational approach reveals that unique - non-resonant and resonant - chemical interactions among the tip and the molecule significantly alter the TERS spectra and are mainly responsible for the high, possibly sub-Angstrom spatial resolution.
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Affiliation(s)
- Kevin Fiederling
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.
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Vedad J, Domaradzki ME, Mojica ERE, Chang EJ, Profit AA, Desamero RZB. Conformational Differentiation of α-Cyanohydroxycinnamic Acid Isomers: A Raman Spectroscopic Study. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2017; 48:1282-1288. [PMID: 29225410 PMCID: PMC5720387 DOI: 10.1002/jrs.5209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Two α-cyanohydroxycinnamic acid positional isomers, α-cyano-4-hydroxycinnamic acid (CHCA4) and α-cyano-3-hydroxycinnamic acid (CHCA3), were characterized using Raman spectroscopy. We analyzed the implications of the collected Raman spectral shifts, and verified them through other spectroscopic techniques, to arrive at plausible three dimensional structures of CHCA3 and CHCA4. The positions of these groups were mapped by systematically analyzing the orientation and type of interactions functional groups make in each CHCA isomer. We determined whether or not the carboxylic moieties are forming dimeric links and ascertained the existence of ring-ring π-stacking interactions. We also assessed the nature of the hydrogen bonding between -CN and -OH groups. The results were then taken together to model plausible three dimensional structures for each compound. The data revealed a structure for CHCA4 that matches the published x-ray crystallographic structure. We then applied the same spectral analysis to CHCA3 to reveal its plausible three dimensional structure. The structural details revealed may account for the functional properties of the two α-cyanohydroxycinnamic acid positional isomers.
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Affiliation(s)
- Jayson Vedad
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, 11451 and Ph.D Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York, 10016 (United States)
| | - Maciej E. Domaradzki
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, 11451 and Ph.D Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York, 10016 (United States)
| | | | - Emmanuel J. Chang
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, 11451 and Ph.D Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York, 10016 (United States)
| | - Adam A. Profit
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, 11451 and Ph.D Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York, 10016 (United States)
| | - Ruel Z. B. Desamero
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, 11451 and Ph.D Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, New York, 10016 (United States)
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Latorre F, Kupfer S, Bocklitz T, Kinzel D, Trautmann S, Gräfe S, Deckert V. Spatial resolution of tip-enhanced Raman spectroscopy - DFT assessment of the chemical effect. NANOSCALE 2016; 8:10229-10239. [PMID: 27123952 DOI: 10.1039/c6nr00093b] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Experimental evidence of extremely high spatial resolution of tip-enhanced Raman scattering (TERS) has been recently demonstrated. Here, we present a full quantum chemical description (at the density functional level of theory) of the non-resonant chemical effects on the Raman spectrum of an adenine molecule mapped by a tip, modeled as a single silver atom or a small silver cluster. We show pronounced changes in the Raman pattern and its intensities depending on the conformation of the nanoparticle-substrate system, concluding that the spatial resolution of the chemical contribution of TERS can be in the sub-nm range.
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Affiliation(s)
- Federico Latorre
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany.
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