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  • Technical Review
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Fundamental understanding and applications of plasmon-enhanced Raman spectroscopy

Abstract

Plasmon-enhanced Raman spectroscopy (PERS), including surface-enhanced Raman spectroscopy, shell-isolated nanoparticle-enhanced Raman spectroscopy and tip-enhanced Raman spectroscopy, has witnessed substantial development over the past 20 years. These techniques can provide fingerprint information on target materials with sensitivities down to the single-molecule level and with sufficient spatial resolution to observe individual vibrational modes. PERS has thus found applications in diverse areas, ranging from bioanalysis to materials characterization. In this Technical Review, we survey the fundamental principles, advantages and limitations of using localized surface plasmon resonance to enhance the Raman signal in PERS. We discuss the issues that influence the sensitivity and interpretation of PERS results and provide an overview of state-of-the-art PERS applications in materials characterization, bioanalysis and the study of surfaces and interfaces. We also troubleshoot common experimental issues, largely based on our own experience. Finally, we conclude by examining future directions and issues to be addressed for the further development of PERS techniques.

Key points

  • Plasmon-enhanced Raman spectroscopy (PERS) can provide fingerprint information with single-molecule sensitivity and subnanometre spatial resolution for various targets, including small molecules, biomolecules, living cells and 2D materials.

  • The Raman signal in PERS is mainly enhanced through localized surface plasmon resonance (LSPR) of nanostructures, and vibrational modes appearing at LSPR wavelengths with different scattering strengths may experience different enhancements.

  • Although chemical enhancement is generally weak, it significantly changes the relative intensities of the Raman peaks of different vibrational modes.

  • Plasmonic enhancement requires the design of appropriate nanostructures, with LSPR showing optimal enhancement at the excitation wavelength under the detection configuration.

  • Target species need to be located or selectively trapped in the hot spots formed in the plasmonic nanogaps to achieve the highest sensitivity; <1% of a surface contributes to 80% of the signal.

  • Challenges in the field include realizing single-molecule detection in complex matrices, avoiding interference from impurities and, for tip-enhanced Raman spectroscopy, achieving a high spatial resolution by using the tip alone without electromagnetic coupling with a substrate.

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Fig. 1: Working configurations of PERS techniques.
Fig. 2: Engineering SERS substrates.
Fig. 3: Issues in the practical use of plasmon-enhanced Raman spectroscopy.
Fig. 4: Application of plasmon-enhanced Raman spectroscopy for the analysis of surfaces and interfaces.
Fig. 5: Application of TERS for nanoscale and atomic-scale materials characterization.
Fig. 6: Application of plasmon-enhanced Raman spectroscopy for bioanalysis.

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References

  1. Ewen, S. & Geoffrey, D. Modern Raman Spectroscopy: A Practical Approach Ch. 1 (Wiley, 2005).

  2. Wu, G.-Z. Raman Spectroscopy: An Intensity Approach Ch. 1 (World Scientific, 2016).

  3. Turrell, G. & Corset, J. Raman Spectroscopy: Development and Applications Ch. 1 (Academic, 1996).

  4. Rousseau, D. L., Friedman, J. M. & Williams, P. F. The Resonance Raman Effect Ch. 1 (Springer, 1979).

  5. Parker, F. S. Applications of Infrared, Raman, and Resonance Raman Spectroscopy in Biochemistry Ch. 1 (Plenum, 1983).

  6. Hellwarth, R. W. Theory of stimulated Raman scattering. Phys. Rev. 130, 1850–1852 (1963).

    ADS  Google Scholar 

  7. Maier, M., Kaiser, W. & Giordmaine, J. A. Intense light bursts in the stimulated Raman effect. Phys. Rev. Lett. 17, 1275–1277 (1966).

    ADS  Google Scholar 

  8. Begley, R. F., Harvey, A. B. & Byer, R. L. Coherent anti-Stokes Raman spectroscopy. Appl. Phys. Lett. 25, 387–390 (1974).

    ADS  Google Scholar 

  9. Cheng, J.-X. & Xie, X. S. Coherent anti-Stokes Raman scattering microscopy: instrumentation, theory, and applications. J. Phys. Chem. B 108, 827–840 (2004).

    Google Scholar 

  10. Fleischmann, M., Hendra, P. J. & McQuillan, A. J. Raman spectra of pyridine adsorbed at a silver electrode. Chem. Phys. Lett. 26, 163–166 (1974).

    ADS  Google Scholar 

  11. Jeanmaire, D. L. & Van Duyne, R. P. Surface Raman spectroelectrochemistry: part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode. J. Electroanal. Chem. 84, 1–20 (1977).

    Google Scholar 

  12. Albrecht, M. G. & Creighton, J. A. Anomalously intense Raman spectra of pyridine at a silver electrode. J. Am. Chem. Soc. 99, 5215–5217 (1977).

    Google Scholar 

  13. Langer, J. et al. Present and future of surface-enhanced Raman scattering. ACS Nano 14, 28–117 (2020). A review covering the principles and applications of SERS.

    Google Scholar 

  14. Stockle, R. M., Suh, Y. D., Deckert, V. & Zenobi, R. Nanoscale chemical analysis by tip-enhanced Raman spectroscopy. Chem. Phys. Lett. 318, 131–136 (2000).

    ADS  Google Scholar 

  15. Anderson, M. S. Locally enhanced Raman spectroscopy with an atomic force microscope. Appl. Phys. Lett. 76, 3130–3132 (2000).

    ADS  Google Scholar 

  16. Hayazawa, N., Inouye, Y., Sekkat, Z. & Kawata, S. Metallized tip amplification of near-field Raman scattering. Opt. Commun. 183, 333–336 (2000).

    ADS  Google Scholar 

  17. Pettinger, B., Picardi, G., Schuster, R. & Ertl, G. Surface enhanced Raman spectroscopy: towards single molecule spectroscopy. Electrochemistry 68, 942–949 (2000).

    Google Scholar 

  18. Li, J. F. et al. Shell-isolated nanoparticle-enhanced Raman spectroscopy. Nature 464, 392–395 (2010). The first paper on SHINERS.

    ADS  Google Scholar 

  19. Li, J.-F., Zhang, Y.-J., Ding, S.-Y., Panneerselvam, R. & Tian, Z.-Q. Core–shell nanoparticle-enhanced Raman spectroscopy. Chem. Rev. 117, 5002–5069 (2017).

    Google Scholar 

  20. Aroca, R. F. Plasmon enhanced spectroscopy. Phys. Chem. Chem. Phys. 15, 5355–5363 (2013).

    Google Scholar 

  21. Ding, S.-Y. et al. Nanostructure-based plasmon-enhanced Raman spectroscopy for surface analysis of materials. Nat. Rev. Mater. 1, 16021 (2016). A review on PERS and hot spots.

    ADS  Google Scholar 

  22. Wu, D.-Y., Li, J.-F., Ren, B. & Tian, Z.-Q. Electrochemical surface-enhanced Raman spectroscopy of nanostructures. Chem. Soc. Rev. 37, 1025–1041 (2008).

    Google Scholar 

  23. Schlücker, S. Surface-enhanced Raman spectroscopy: concepts and chemical applications. Angew. Chem. Int. Ed. 53, 4756–4795 (2014).

    Google Scholar 

  24. Zrimsek, A. B. et al. Single-molecule chemistry with surface- and tip-enhanced Raman spectroscopy. Chem. Rev. 117, 7583–7613 (2017).

    Google Scholar 

  25. Zhan, C. et al. From plasmon-enhanced molecular spectroscopy to plasmon-mediated chemical reactions. Nat. Rev. Chem. 2, 216–230 (2018).

    Google Scholar 

  26. Morton, S. M., Silverstein, D. W. & Jensen, L. Theoretical studies of plasmonics using electronic structure methods. Chem. Rev. 111, 3962–3994 (2011).

    Google Scholar 

  27. Itoh, T., Yamamoto, Y. S. & Ozaki, Y. Plasmon-enhanced spectroscopy of absorption and spontaneous emissions explained using cavity quantum optics. Chem. Soc. Rev. 46, 3904–3921 (2017).

    Google Scholar 

  28. Le Ru, E.C. & Etchegoin, P. G. Principles of Surface-enhanced Raman Spectroscopy: and Related Plasmonic Effects Ch. 1–3 (Elsevier, 2008). An excellent book on the principles of SERS and LSPR.

  29. Wang, X. et al. Tip-enhanced Raman spectroscopy for surfaces and interfaces. Chem. Soc. Rev. 46, 4020–4041 (2017).

    Google Scholar 

  30. Shao, F. & Zenobi, R. Tip-enhanced Raman spectroscopy: principles, practice, and applications to nanospectroscopic imaging of 2D materials. Anal. Bioanal. Chem. 411, 37–61 (2019).

    Google Scholar 

  31. Jamieson, L. E., Asiala, S. M., Gracie, K., Faulds, K. & Graham, D. Bioanalytical measurements enabled by surface-enhanced Raman scattering (SERS) probes. Annu. Rev. Anal. Chem. 10, 415–437 (2017).

    Google Scholar 

  32. Zheng, X.-S., Jahn, I. J., Weber, K., Cialla-May, D. & Popp, J. Label-free SERS in biological and biomedical applications: recent progress, current challenges and opportunities. Spectrochim. Acta A 197, 56–77 (2018).

    ADS  Google Scholar 

  33. Zong, C. et al. Surface-enhanced Raman spectroscopy for bioanalysis: reliability and challenges. Chem. Rev. 118, 4946–4980 (2018).

    Google Scholar 

  34. Novotny, L. & van Hulst, N. Antennas for light. Nat. Photonics 5, 83–90 (2011).

    ADS  Google Scholar 

  35. Bharadwaj, P., Deutsch, B. & Novotny, L. Optical antennas. Adv. Opt. Photonics 1, 438–483 (2009).

    ADS  Google Scholar 

  36. Biagioni, P., Huang, J.-S. & Hecht, B. Nanoantennas for visible and infrared radiation. Rep. Prog. Phys. 75, 024402 (2012).

    ADS  Google Scholar 

  37. Liu, B.-J. et al. Extraction of absorption and scattering contribution of metallic nanoparticles toward rational synthesis and application. Anal. Chem. 87, 1058–1065 (2015).

    Google Scholar 

  38. Xu, H., Bjerneld, E. J., Käll, M. & Börjesson, L. Spectroscopy of single hemoglobin molecules by surface enhanced Raman scattering. Phys. Rev. Lett. 83, 4357–4360 (1999). A study demonstrating the importance of nanogaps in SERS using electromagnetic calculations and experiments.

    ADS  Google Scholar 

  39. Lombardi, J. R. & Birke, R. L. A unified approach to surface-enhanced Raman spectroscopy. J. Phys. Chem. C 112, 5605–5617 (2008).

    Google Scholar 

  40. Kambhampati, P., Child, C. M., Foster, M. C. & Campion, A. On the chemical mechanism of surface enhanced Raman scattering: experiment and theory. J. Chem. Phys. 108, 5013–5026 (1998).

    ADS  Google Scholar 

  41. The SAO/NASA Astrophysics Data System. General discussion. Faraday Discuss. 132, 227–247 (2006).

  42. Valley, N., Greeneltch, N., Van Duyne, R. P. & Schatz, G. C. A look at the origin and magnitude of the chemical contribution to the enhancement mechanism of surface-enhanced Raman spectroscopy (SERS): theory and experiment. J. Phys. Chem. Lett. 4, 2599–2604 (2013).

    Google Scholar 

  43. Morton, S. M. & Jensen, L. Understanding the molecule−surface chemical coupling in SERS. J. Am. Chem. Soc. 131, 4090–4098 (2009).

    Google Scholar 

  44. Birke, R. L., Lombardi, J. R., Saidi, W. A. & Norman, P. Surface-enhanced Raman scattering due to charge-transfer resonances: a time-dependent density functional theory study of Ag13-4-mercaptopyridine. J. Phys. Chem. C 120, 20721–20735 (2016).

    Google Scholar 

  45. Lombardi, J. R. & Birke, R. L. The theory of surface-enhanced Raman scattering. J. Chem. Phys. 136, 144704 (2012).

    ADS  Google Scholar 

  46. Ciracì, C. et al. Probing the ultimate limits of plasmonic enhancement. Science 337, 1072–1074 (2012).

    ADS  Google Scholar 

  47. Barbry, M. et al. Atomistic near-field nanoplasmonics: reaching atomic-scale resolution in nanooptics. Nano Lett. 15, 3410–3419 (2015).

    ADS  Google Scholar 

  48. Benz, F. et al. Single-molecule optomechanics in ‘picocavities’. Science 354, 726–729 (2016). Study demonstrating the concept of the picocavity.

    ADS  Google Scholar 

  49. Ahmed, A. & Gordon, R. Single molecule directivity enhanced Raman scattering using nanoantennas. Nano Lett. 12, 2625–2630 (2012).

    ADS  Google Scholar 

  50. Punj, D. et al. A plasmonic ‘antenna-in-box’ platform for enhanced single-molecule analysis at micromolar concentrations. Nat. Nanotechnol. 8, 512–516 (2013).

    ADS  Google Scholar 

  51. Gordon, R. & Ahmed, A. Reaching the limits of enhancement in (sub) nanometer metal structures. ACS Photonics 5, 4222–4228 (2018).

    Google Scholar 

  52. Lee, J., Crampton, K. T., Tallarida, N. & Apkarian, V. A. Visualizing vibrational normal modes of a single molecule with atomically confined light. Nature 568, 78–82 (2019). A study in which angstrom-scale resolution was achieved by using TERS under UHV to atomically parse the intramolecular charges and currents driven by vibrations.

    ADS  Google Scholar 

  53. Zhang, Y. et al. Visually constructing the chemical structure of a single molecule by scanning Raman microscopy. Natl Sci. Rev. 6, 1169–1175 (2019).

    Google Scholar 

  54. Zhang, R. et al. Chemical mapping of a single molecule by plasmon-enhanced Raman scattering. Nature 498, 82–86 (2013). The first study demonstrating subnanometre resolution of TERS under UHV and low temperature.

    ADS  Google Scholar 

  55. Duan, S., Tian, G. & Luo, Y. Visualization of vibrational modes in real space by tip-enhanced non-resonant Raman spectroscopy. Angew. Chem. Int. Ed. 55, 1041–1045 (2016).

    Google Scholar 

  56. Zhang, C., Chen, B.-Q. & Li, Z.-Y. Optical origin of subnanometer resolution in tip-enhanced Raman mapping. J. Phys. Chem. C 119, 11858–11871 (2015).

    Google Scholar 

  57. Roelli, P., Galland, C., Piro, N. & Kippenberg, T. J. Molecular cavity optomechanics as a theory of plasmon-enhanced Raman scattering. Nat. Nanotechnol. 11, 164–169 (2016).

    ADS  Google Scholar 

  58. Kim, S. et al. High external-efficiency nanofocusing for lens-free near-field optical nanoscopy. Nat. Photonics 13, 636–643 (2019).

    ADS  Google Scholar 

  59. Chulhai, D. V. & Jensen, L. Determining molecular orientation with surface-enhanced Raman scattering using inhomogenous electric fields. J. Phys. Chem. C 117, 19622–19631 (2013).

    Google Scholar 

  60. Lee, J. et al. Tip-enhanced Raman spectromicroscopy of Co(ii)-tetraphenylporphyrin on Au(111): toward the chemists’ microscope. ACS Nano 11, 11466–11474 (2017).

    Google Scholar 

  61. Iida, T., Aiba, Y. & Ishihara, H. Anomalous optical selection rule of an organic molecule controlled by extremely localized light field. Appl. Phys. Lett. 98, 053108 (2011).

    ADS  Google Scholar 

  62. Takase, M. et al. Selection-rule breakdown in plasmon-induced electronic excitation of an isolated single-walled carbon nanotube. Nat. Photonics 7, 550–554 (2013).

    ADS  Google Scholar 

  63. Ebbesen, T. W. Hybrid light–matter states in a molecular and material science perspective. Acc. Chem. Res. 49, 2403–2412 (2016).

    Google Scholar 

  64. Nagasawa, F., Takase, M. & Murakoshi, K. Raman enhancement via polariton states produced by strong coupling between a localized surface plasmon and dye excitons at metal nanogaps. J. Phys. Chem. Lett. 5, 14–19 (2014).

    Google Scholar 

  65. Kato, F. et al. Active tuning of strong coupling states between dye excitons and localized surface plasmons via electrochemical potential control. ACS Photonics 5, 788–796 (2018).

    Google Scholar 

  66. Ikeda, K., Fujimoto, N., Uehara, H. & Uosaki, K. Raman scattering of aryl isocyanide monolayers on atomically flat Au(111) single crystal surfaces enhanced by gap-mode plasmon excitation. Chem. Phys. Lett. 460, 205–208 (2008).

    ADS  Google Scholar 

  67. Ikeda, K. et al. Plasmonic enhancement of Raman scattering on non-SERS-active platinum substrates. J. Phys. Chem. C 113, 11816–11821 (2009).

    Google Scholar 

  68. Chen, S.-Y. et al. Gold nanoparticles on polarizable surfaces as Raman scattering antennas. ACS Nano 4, 6535–6546 (2010).

    Google Scholar 

  69. Ikeda, K., Sato, J. & Uosaki, K. Surface-enhanced Raman scattering at well-defined single crystalline faces of platinum-group metals induced by gap-mode plasmon excitation. J. Photochem. Photobiol. A 221, 175–180 (2011).

    Google Scholar 

  70. Mubeen, S. et al. Plasmonic properties of gold nanoparticles separated from a gold mirror by an ultrathin oxide. Nano Lett. 12, 2088–2094 (2012).

    ADS  Google Scholar 

  71. Hu, J., Tanabe, M., Sato, J., Uosaki, K. & Ikeda, K. Effects of atomic geometry and electronic structure of platinum surfaces on molecular adsorbates studied by gap-mode SERS. J. Am. Chem. Soc. 136, 10299–10307 (2014).

    Google Scholar 

  72. Hu, J., Hoshi, N., Uosaki, K. & Ikeda, K. Vibrational spectroscopic observation of aomic-scale local surface sites using site-selective signal enhancement. Nano Lett. 15, 7982–7986 (2015).

    ADS  Google Scholar 

  73. Baker, G. A. & Moore, D. S. Progress in plasmonic engineering of surface-enhanced Raman-scattering substrates toward ultra-trace analysis. Anal. Bioanal. Chem. 382, 1751–1770 (2005).

    Google Scholar 

  74. Banholzer, M. J., Millstone, J. E., Qin, L. & Mirkin, C. A. Rationally designed nanostructures for surface-enhanced Raman spectroscopy. Chem. Soc. Rev. 37, 885–897 (2008).

    Google Scholar 

  75. Fan, M., Andrade, G. F. & Brolo, A. G. A review on the fabrication of substrates for surface enhanced Raman spectroscopy and their applications in analytical chemistry. Anal. Chim. Acta 693, 7–25 (2011).

    Google Scholar 

  76. Cialla, D. et al. Surface-enhanced Raman spectroscopy (SERS): progress and trends. Anal. Bioanal. Chem. 403, 27–54 (2012).

    Google Scholar 

  77. Lin, X. M., Cui, Y., Xu, Y. H., Ren, B. & Tian, Z. Q. Surface-enhanced Raman spectroscopy: substrate-related issues. Anal. Bioanal. Chem. 394, 1729–1745 (2009).

    Google Scholar 

  78. Van Duyne, R. P., Hulteen, J. & Treichel, D. Atomic force microscopy and surface-enhanced Raman spectroscopy. I. Ag island films and Ag film over polymer nanosphere surfaces supported on glass. J. Chem. Phys. 99, 2101–2115 (1993).

    ADS  Google Scholar 

  79. Tao, A. R., Habas, S. & Yang, P. Shape control of colloidal metal nanocrystals. Small 4, 310–325 (2008).

    Google Scholar 

  80. Sun, Y. & Xia, Y. Shape-controlled synthesis of gold and silver nanoparticles. Science 298, 2176–2179 (2002).

    ADS  Google Scholar 

  81. Camden, J. P. et al. Probing the structure of single-molecule surface-enhanced Raman scattering hot spots. J. Am. Chem. Soc. 130, 12616–12617 (2008).

    Google Scholar 

  82. Thacker, V. V. et al. DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering. Nat. Commun. 5, 3448 (2014).

    ADS  Google Scholar 

  83. Chen, Z., Choi, C. K. K. & Wang, Q. Origin of the plasmonic chirality of gold nanorod trimers templated by DNA origami. ACS Appl. Mater. Interfaces 10, 26835–26840 (2018).

    Google Scholar 

  84. Pilo-Pais, M., Watson, A., Demers, S., LaBean, T. H. & Finkelstein, G. Surface-enhanced Raman scattering plasmonic enhancement using DNA origami-based complex metallic nanostructures. Nano Lett. 14, 2099–2104 (2014).

    ADS  Google Scholar 

  85. Jones, M. R., Osberg, K. D., Macfarlane, R. J., Langille, M. R. & Mirkin, C. A. Templated techniques for the synthesis and assembly of plasmonic nanostructures. Chem. Rev. 111, 3736–3827 (2011).

    Google Scholar 

  86. Tao, A. R., Huang, J. & Yang, P. Langmuir–Blodgettry of nanocrystals and nanowires. Acc. Chem. Res. 41, 1662–1673 (2008).

    Google Scholar 

  87. Tao, A., Sinsermsuksakul, P. & Yang, P. Tunable plasmonic lattices of silver nanocrystals. Nat. Nanotechnol. 2, 435–440 (2007).

    ADS  Google Scholar 

  88. Kleinman, S. L., Frontiera, R. R., Henry, A.-I., Dieringer, J. A. & Van Duyne, R. Creating, characterizing, and controlling chemistry with SERS hot spots. Phys. Chem. Chem. Phys. 15, 21–36 (2013).

    Google Scholar 

  89. Kahl, M., Voges, E., Kostrewa, S., Viets, C. & Hill, W. Periodically structured metallic substrates for SERS. Sens. Actuat. B 51, 285–291 (1998).

    Google Scholar 

  90. Gordon, R., Sinton, D., Kavanagh, K. L. & Brolo, A. G. A new generation of sensors based on extraordinary optical transmission. Acc. Chem. Res. 41, 1049–1057 (2008).

    Google Scholar 

  91. Gopinath, A., Boriskina, S. V., Reinhard, B. M. & Dal Negro, L. Deterministic aperiodic arrays of metal nanoparticles for surface-enhanced Raman scattering (SERS). Opt. Express 17, 3741–3753 (2009).

    ADS  Google Scholar 

  92. Li, J. et al. 300 mm wafer-level, ultra-dense arrays of Au-capped nanopillars with sub-10 nm gaps as reliable SERS substrates. Nanoscale 6, 12391–12396 (2014).

    ADS  Google Scholar 

  93. Bagheri, S., Giessen, H. & Neubrech, F. Large-area antenna-assisted SEIRA substrates by laser interference lithography. Adv. Opt. Mater. 2, 1050–1056 (2014).

    Google Scholar 

  94. Jeon, H. C., Heo, C. J., Lee, S. Y., Park, S. G. & Yang, S. M. Optically tunable arrayed structures for highly sensitive plasmonic detection via simplified holographic lithography. J. Mater. Chem. 22, 4603–4606 (2012).

    Google Scholar 

  95. Liu, B. W. et al. Large-area hybrid plasmonic optical cavity (HPOC) substrates for surface-enhanced Raman spectroscopy. Adv. Funct. Mater. 28, 1802263 (2018).

    Google Scholar 

  96. Le Ru, E. C. & Etchegoin, P. G. Rigorous justification of the |E|4 enhancement factor in surface enhanced Raman spectroscopy. Chem. Phys. Lett. 423, 63–66 (2006).

    ADS  Google Scholar 

  97. Le Ru, E. C. & Etchegoin, P. G. Quantifying SERS enhancements. MRS Bull. 38, 631–640 (2013).

    Google Scholar 

  98. Cai, W. B. et al. Investigation of surface-enhanced Raman scattering from platinum electrodes using a confocal Raman microscope: dependence of surface roughening pretreatment. Surf. Sci. 406, 9–22 (1998).

    ADS  Google Scholar 

  99. Pettinger, B., Schambach, P., Villagómez, C. J. & Scott, N. Tip-enhanced Raman spectroscopy: near-fields acting on a few molecules. Annu. Rev. Phys. Chem. 63, 379–399 (2012).

    ADS  Google Scholar 

  100. Stadler, J., Schmid, T. & Zenobi, R. Developments in and practical guidelines for tip-enhanced Raman spectroscopy. Nanoscale 4, 1856–1870 (2012).

    ADS  Google Scholar 

  101. Kawata, S. & Shalaev, V. M. Tip Enhancement (Elsevier, 2007).

  102. Richard-Lacroix, M., Zhang, Y., Dong, Z. & Deckert, V. Mastering high resolution tip-enhanced Raman spectroscopy: towards a shift of perception. Chem. Soc. Rev. 46, 3922–3944 (2017).

    Google Scholar 

  103. Moskovits, M. Surface selection rules. J. Chem. Phys. 77, 4408–4416 (1982).

    ADS  Google Scholar 

  104. Jiang, S. et al. Distinguishing adjacent molecules on a surface using plasmon-enhanced Raman scattering. Nat. Nanotechnol. 10, 865–869 (2015).

    ADS  Google Scholar 

  105. Weiss, A. & Haran, G. Time-dependent single-molecule Raman scattering as a probe of surface dynamics. J. Phys. Chem. B 105, 12348–12354 (2001).

    Google Scholar 

  106. Cui, L., Wu, D.-Y., Wang, A., Ren, B. & Tian, Z.-Q. Charge-transfer enhancement involved in the SERS of adenine on Rh and Pd demonstrated by ultraviolet to visible laser excitation. J. Phys. Chem. C 114, 16588–16595 (2010).

    Google Scholar 

  107. Ward, D. R., Corley, D. A., Tour, J. M. & Natelson, D. Vibrational and electronic heating in nanoscale junctions. Nat. Nanotechnol. 6, 33–38 (2011).

    ADS  Google Scholar 

  108. Itoh, T. et al. Second enhancement in surface-enhanced resonance Raman scattering revealed by an analysis of anti-Stokes and Stokes Raman spectra. Phys. Rev. B 76, 085405 (2007).

    ADS  Google Scholar 

  109. Lin, K.-Q. et al. Plasmonic photoluminescence for recovering native chemical information from surface-enhanced Raman scattering. Nat. Commun. 8, 14891 (2017).

    ADS  Google Scholar 

  110. Yoshida, K.-i, Itoh, T., Biju, V., Ishikawa, M. & Ozaki, Y. Experimental evaluation of the twofold electromagnetic enhancement theory of surface-enhanced resonance Raman scattering. Phys. Rev. B 79, 085419 (2009).

    ADS  Google Scholar 

  111. Bailey, M. R., Pentecost, A. M., Selimovic, A., Martin, R. S. & Schultz, Z. D. Sheath-flow microfluidic approach for combined surface enhanced Raman scattering and electrochemical detection. Anal. Chem. 87, 4347–4355 (2015).

    Google Scholar 

  112. Lin, K.-Q. et al. Size effect on SERS of gold nanorods demonstrated via single nanoparticle spectroscopy. J. Phys. Chem. C 120, 20806–20813 (2016).

    Google Scholar 

  113. Scott, B. L. & Carron, K. T. Dynamic surface enhanced Raman spectroscopy (SERS): extracting SERS from normal Raman scattering. Anal. Chem. 84, 8448–8451 (2012).

    Google Scholar 

  114. Asiala, S. M. & Schultz, Z. D. Label-free in situ detection of individual macromolecular assemblies by surface enhanced Raman scattering. Chem. Commun. 49, 4340–4342 (2013).

    Google Scholar 

  115. van Lierop, D. et al. Positively charged silver nanoparticles and their effect on surface-enhanced Raman scattering of dye-labelled oligonucleotides. Chem. Commun. 48, 8192–8194 (2012).

    Google Scholar 

  116. Guerrini, L., Krpetic´, Ž., van Lierop, D., Alvarez-Puebla, R. A. & Graham, D. Direct surface-enhanced Raman scattering analysis of DNA duplexes. Angew. Chem. Int. Ed. 54, 1144–1148 (2015).

    Google Scholar 

  117. Zhan, L., Zhen, S. J., Wan, X. Y., Gao, P. F. & Huang, C. Z. A sensitive surface-enhanced Raman scattering enzyme-catalyzed immunoassay of respiratory syncytial virus. Talanta 148, 308–312 (2016).

    Google Scholar 

  118. Xi, W., Shrestha, B. K. & Haes, A. J. Promoting intra- and intermolecular interactions in surface-enhanced Raman scattering. Anal. Chem. 90, 128–143 (2018).

    Google Scholar 

  119. Haupt, K. & Mosbach, K. Molecularly imprinted polymers and their use in biomimetic sensors. Chem. Rev. 100, 2495–2504 (2000).

    Google Scholar 

  120. Blackie, E. J., Le Ru, E. C. & Etchegoin, P. G. Single-molecule surface-enhanced Raman spectroscopy of nonresonant molecules. J. Am. Chem. Soc. 131, 14466–14472 (2009).

    Google Scholar 

  121. Strehle, K. R. et al. A reproducible surface-enhanced Raman spectroscopy approach. Online SERS measurements in a segmented microfluidic system. Anal. Chem. 79, 1542–1547 (2007).

    Google Scholar 

  122. Zhang, D., Xie, Y., Deb, S. K., Davison, V. J. & Ben-Amotz, D. Isotope edited internal standard method for quantitative surface-enhanced Raman spectroscopy. Anal. Chem. 77, 3563–3569 (2005).

    Google Scholar 

  123. Lorén, A. et al. Internal standard in surface-enhanced Raman spectroscopy. Anal. Chem. 76, 7391–7395 (2004).

    Google Scholar 

  124. Shen, W. et al. Reliable quantitative SERS analysis facilitated by core–shell nanoparticles with embedded internal standards. Angew. Chem. Int. Ed. 54, 7308–7312 (2015).

    Google Scholar 

  125. Dong, J.-C. et al. In situ Raman spectroscopic evidence for oxygen reduction reaction intermediates at platinum single-crystal surfaces. Nat. Energy 4, 60–67 (2019). A report of the direct observation of intermediates in the oxygen reduction reaction with SHINERS.

    ADS  Google Scholar 

  126. Zhong, J.-H. et al. Probing the electronic and catalytic properties of a bimetallic surface with 3 nm resolution. Nat. Nanotechnol. 12, 132 (2017).

    ADS  Google Scholar 

  127. Su, H.-S. et al. Real-space observation of atomic site-specific electronic properties of a Pt nanoisland/Au(111) bimetallic surface by tip-enhanced Raman spectroscopy. Angew. Chem. Int. Ed. 57, 13177–13181 (2018).

    Google Scholar 

  128. Zeng, Z.-C. et al. Electrochemical tip-enhanced Raman spectroscopy. J. Am. Chem. Soc. 137, 11928–11931 (2015). A demonstration of electrochemical TERS.

    Google Scholar 

  129. Kurouski, D., Mattei, M. & Van Duyne, R. P. Probing redox reactions at the nanoscale with electrochemical tip-enhanced Raman spectroscopy. Nano Lett. 15, 7956–7962 (2015).

    ADS  Google Scholar 

  130. Martín Sabanés, N., Ohto, T., Andrienko, D., Nagata, Y. & Domke, K. F. Electrochemical TERS elucidates potential-induced molecular reorientation of adenine/Au(111). Angew. Chem. Int. Ed. 56, 9796–9801 (2017).

    Google Scholar 

  131. Goubert, G., Chen, X., Jiang, S. & Van Duyne, R. P. In situ electrochemical tip-enhanced Raman spectroscopy with a chemically modified tip. J. Phys. Chem. Lett. 9, 3825–3828 (2018).

    Google Scholar 

  132. Huang, S.-C. et al. Electrochemical tip-enhanced Raman spectroscopy with improved sensitivity enabled by a water immersion objective. Anal. Chem. 91, 11092–11097 (2019).

    Google Scholar 

  133. Touzalin, T., Joiret, S., Lucas, I. T. & Maisonhaute, E. Electrochemical tip-enhanced Raman spectroscopy imaging with 8 nm lateral resolution. Electrochem. Commun. 108, 106557 (2019).

    Google Scholar 

  134. Chiang, N. et al. Conformational contrast of surface-mediated molecular switches yields ångstrom-scale spatial resolution in ultrahigh vacuum tip-enhanced Raman spectroscopy. Nano Lett. 16, 7774–7778 (2016).

    ADS  Google Scholar 

  135. Lee, J., Tallarida, N., Chen, X., Jensen, L. & Apkarian, V. A. Microscopy with a single-molecule scanning electrometer. Sci. Adv. 4, eaat5472 (2018).

    ADS  Google Scholar 

  136. Deckert-Gaudig, T., Kämmer, E. & Deckert, V. Tracking of nanoscale structural variations on a single amyloid fibril with tip-enhanced Raman scattering. J. Biophotonics 5, 215–219 (2012).

    Google Scholar 

  137. Butler, S. Z. et al. Progress, challenges, and opportunities in two-dimensional materials beyond graphene. ACS Nano 7, 2898–2926 (2013).

    Google Scholar 

  138. Duan, X., Wang, C., Pan, A., Yu, R. & Duan, X. Two-dimensional transition metal dichalcogenides as atomically thin semiconductors: opportunities and challenges. Chem. Soc. Rev. 44, 8859–8876 (2015).

    Google Scholar 

  139. Huang, T.-X. et al. Probing the edge-related properties of atomically thin MoS2 at nanoscale. Nat. Commun. 10, 5544 (2019).

    ADS  Google Scholar 

  140. Nanda, J. et al. Unraveling the nanoscale heterogeneity of solid electrolyte interphase using tip-enhanced Raman spectroscopy. Joule 3, 2001–2019 (2019).

    Google Scholar 

  141. Su, W., Kumar, N., Krayev, A. & Chaigneau, M. In situ topographical chemical and electrical imaging of carboxyl graphene oxide at the nanoscale. Nat. Commun. 9, 2891 (2018).

    ADS  Google Scholar 

  142. Jariwala, D. et al. Nanoscale doping heterogeneity in few-layer WSe2 exfoliated onto noble metals revealed by correlated SPM and TERS imaging. 2D Mater. 5, 035003 (2018).

    Google Scholar 

  143. Smithe, K. K. H. et al. Nanoscale heterogeneities in monolayer MoSe2 revealed by correlated scanning probe microscopy and tip-enhanced Raman spectroscopy. ACS Appl. Nano Mater. 1, 572–579 (2018).

    Google Scholar 

  144. Huang, J.-Y., Zong, C., Xu, L.-J., Cui, Y. & Ren, B. Clean and modified substrates for direct detection of living cells by surface-enhanced Raman spectroscopy. Chem. Commun. 47, 5738–5740 (2011).

    Google Scholar 

  145. Xu, L.-J. et al. Label-free detection of native proteins by surface-enhanced Raman spectroscopy using iodide-modified nanoparticles. Anal. Chem. 86, 2238–2245 (2014).

    Google Scholar 

  146. Xu, L.-J. et al. Label-free surface-enhanced Raman spectroscopy detection of DNA with single-base sensitivity. J. Am. Chem. Soc. 137, 5149–5154 (2015).

    Google Scholar 

  147. Vitol, E. A., Orynbayeva, Z., Friedman, G. & Gogotsi, Y. Nanoprobes for intracellular and single cell surface-enhanced Raman spectroscopy (SERS). J. Raman Spectrosc. 43, 817–827 (2012).

    ADS  Google Scholar 

  148. Drescher, D. & Kneipp, J. Nanomaterials in complex biological systems: insights from Raman spectroscopy. Chem. Soc. Rev. 41, 5780–5799 (2012).

    Google Scholar 

  149. Austin, L. A., Kang, B. & El-Sayed, M. A. A new nanotechnology technique for determining drug efficacy using targeted plasmonically enhanced single cell imaging spectroscopy. J. Am. Chem. Soc. 135, 4688–4691 (2013).

    Google Scholar 

  150. Panikkanvalappil, S. R. et al. Hyperoxia induces intracellular acidification in neonatal mouse lung fibroblasts: real-time investigation using plasmonically enhanced Raman spectroscopy. J. Am. Chem. Soc. 138, 3779–3788 (2016).

    Google Scholar 

  151. Aioub, M. & El-Sayed, M. A. A real-time surface enhanced Raman spectroscopy study of plasmonic photothermal cell death using targeted gold nanoparticles. J. Am. Chem. Soc. 138, 1258–1264 (2016).

    Google Scholar 

  152. Šimáková, P., Gautier, J., Procházka, M., Hervé-Aubert, K. & Chourpa, I. Polyethylene-glycol-stabilized Ag nanoparticles for surface-enhanced Raman scattering spectroscopy: Ag surface accessibility studied using metalation of free-base porphyrins. J. Phys. Chem. C 118, 7690–7697 (2014).

    Google Scholar 

  153. Cialla-May, D., Zheng, X. S., Weber, K. & Popp, J. Recent progress in surface-enhanced Raman spectroscopy for biological and biomedical applications: from cells to clinics. Chem. Soc. Rev. 46, 3945–3961 (2017).

    Google Scholar 

  154. Li, P. et al. Fundamentals and applications of surface-enhanced Raman spectroscopy-based biosensors. Curr. Opin. Bio. Eng. 13, 51–59 (2020).

    Google Scholar 

  155. Cao, Y. C., Jin, R., Nam, J.-M., Thaxton, C. S. & Mirkin, C. A. Raman dye-labeled nanoparticle probes for proteins. J. Am. Chem. Soc. 125, 14676–14677 (2003).

    Google Scholar 

  156. Kneipp, J., Kneipp, H., Rajadurai, A., Redmond, R. W. & Kneipp, K. Optical probing and imaging of live cells using SERS labels. J. Raman Spectrosc. 40, 1–5 (2009).

    ADS  Google Scholar 

  157. Song, J., Zhou, J. & Duan, H. Self-assembled plasmonic vesicles of SERS-encoded amphiphilic gold nanoparticles for cancer cell targeting and traceable intracellular drug delivery. J. Am. Chem. Soc. 134, 13458–13469 (2012).

    Google Scholar 

  158. Bishnoi, S. W. et al. All-optical nanoscale pH meter. Nano Lett. 6, 1687–1692 (2006).

    ADS  Google Scholar 

  159. Maher, R. C., Cohen, L. F., Gallop, J. C., Le, Ru,E. C. & Etchegoin, P. G. Temperature-dependent anti-Stokes/Stokes ratios under surface-enhanced Raman scattering conditions. J. Phys. Chem. B 110, 6797–6803 (2006).

    Google Scholar 

  160. Hu, S. et al. Quantifying surface temperature of thermoplasmonic nanostructures. J. Am. Chem. Soc. 140, 13680–13686 (2018).

    Google Scholar 

  161. Pallaoro, A., Braun, G. B., Reich, N. O. & Moskovits, M. Mapping local pH in live cells using encapsulated fluorescent SERS nanotags. Small 6, 618–622 (2010).

    Google Scholar 

  162. Zheng, X.-S. et al. BSA-coated nanoparticles for improved SERS-based intracellular pH sensing. Anal. Chem. 86, 12250–12257 (2014).

    Google Scholar 

  163. Zheng, X.-S., Zong, C., Wang, X. & Ren, B. Cell-penetrating peptide conjugated SERS nanosensor for in situ intracellular pH imaging of single living cells during cell cycle. Anal. Chem. 91, 8383–8389 (2019).

    Google Scholar 

  164. Norrod, K. L. & Rowlen, K. L. Removal of carbonaceous contamination from SERS-active silver by self-assembly of decanethiol. Anal. Chem. 70, 4218–4221 (1998).

    Google Scholar 

  165. Kordesch, M. E. et al. The surface chemistry of the CN group: geometry and bonding. Spectrochim. Acta A 43, 1561–1566 (1987).

    ADS  Google Scholar 

  166. Huang, Y.-F. et al. When the signal is not from the original molecule to be detected: chemical transformation of para-aminothiophenol on Ag during the SERS measurement. J. Am. Chem. Soc. 132, 9244–9246 (2010).

    Google Scholar 

  167. Maruyama, Y., Ishikawa, M. & Futamata, M. Thermal activation of blinking in SERS signal. J. Phys. Chem. B 108, 673–678 (2004).

    Google Scholar 

  168. Sprague-Klein, E. A. et al. Photoinduced plasmon-driven chemistry in trans-1,2-bis(4-pyridyl)ethylene gold nanosphere oligomers. J. Am. Chem. Soc. 140, 10583–10592 (2018).

    Google Scholar 

  169. Sprague-Klein, E. A. et al. Observation of single molecule plasmon-driven electron transfer in isotopically edited 4,4′-bipyridine gold nanosphere oligomers. J. Am. Chem. Soc. 139, 15212–15221 (2017).

    Google Scholar 

  170. Hugall, J. T. & Baumberg, J. J. Demonstrating photoluminescence from Au is electronic inelastic light scattering of a plasmonic metal: the origin of SERS backgrounds. Nano Lett. 15, 2600–2604 (2015).

    ADS  Google Scholar 

  171. Maher, R. C., Cohen, L. F., Le Ru, E. C. & Etchegoin, P. G. A study of local heating of molecules under surface enhanced Raman scattering (SERS) conditions using the anti-Stokes/Stokes ratio. Faraday Discuss. 132, 77–83 (2006).

    ADS  Google Scholar 

  172. Zhang, Z. et al. Insights into the nature of plasmon-driven catalytic reactions revealed by HV-TERS. Nanoscale 5, 3249–3252 (2013).

    ADS  Google Scholar 

  173. Sun, M., Zhang, Z., Zheng, H. & Xu, H. In-situ plasmon-driven chemical reactions revealed by high vacuum tip-enhanced Raman spectroscopy. Sci. Rep. 2, 647 (2012).

    ADS  Google Scholar 

  174. Kneipp, K. et al. Population pumping of excited vibrational states by spontaneous surface-enhanced Raman scattering. Phys. Rev. Lett. 76, 2444–2447 (1996).

    ADS  Google Scholar 

  175. Kneipp, K. et al. Near-infrared surface-enhanced Raman scattering can detect single molecules and observe ‘hot’ vibrational transitions. J. Raman Spectrosc. 29, 743–747 (1998).

    ADS  Google Scholar 

  176. Shin, H.-H. et al. Frequency-domain proof of the existence of atomic-scale SERS hot-spots. Nano Lett. 18, 262–271 (2018).

    ADS  Google Scholar 

  177. Haslett, T. L., Tay, L. & Moskovits, M. Can surface-enhanced Raman scattering serve as a channel for strong optical pumping? J. Chem. Phys. 113, 1641–1646 (2000).

    ADS  Google Scholar 

  178. Brolo, A. G., Sanderson, A. C. & Smith, A. P. Ratio of the surface-enhanced anti-Stokes scattering to the surface-enhanced Stokes–Raman scattering for molecules adsorbed on a silver electrode. Phys. Rev. B 69, 045424 (2004).

    ADS  Google Scholar 

  179. Campion, A. & Mullins, D. R. Normal Raman scattering from pyridine adsorbed on the low-index faces of silver. Chem. Phys. Lett. 94, 576–579 (1983).

    ADS  Google Scholar 

  180. Lippitsch, M. E. Ground-state charge transfer as a mechanism for surface-enhanced Raman scattering. Phys. Rev. B 29, 3101–3110 (1984).

    ADS  Google Scholar 

  181. Patterson, M. L. & Weaver, M. J. Adsorption and oxidation of ethylene at gold electrodes as examined by surface-enhanced Raman spectroscopy. J. Phys. Chem. 89, 1331–1334 (1985).

    Google Scholar 

  182. Chen, C. et al. High spatial resolution nanoslit SERS for single-molecule nucleobase sensing. Nat. Commun. 9, 1733 (2018).

    ADS  Google Scholar 

  183. Huang, J.-A. et al. SERS discrimination of single DNA bases in single oligonucleotides by electro-plasmonic trapping. Nat. Commun. 10, 5321 (2019).

    ADS  Google Scholar 

  184. Kumar, N., Stephanidis, B., Zenobi, R., Wain, A. J. & Roy, D. Nanoscale mapping of catalytic activity using tip-enhanced Raman spectroscopy. Nanoscale 7, 7133–7137 (2015).

    ADS  Google Scholar 

  185. Kumar, N., Wondergem, C. S., Wain, A. J. & Weckhuysen, B. M. In situ nanoscale investigation of catalytic reactions in the liquid phase using zirconia-protected tip-enhanced Raman spectroscopy probes. J. Phys. Chem. Lett. 10, 1669–1675 (2019).

    Google Scholar 

  186. Bhattarai, A. & El-Khoury, P. Z. Nanoscale chemical reaction imaging at the solid–liquid interface via TERS. J. Phys. Chem. Lett. 10, 2817–2822 (2019).

    Google Scholar 

  187. Kang, G., Yang, M., Mattei, M. S., Schatz, G. C. & Van Duyne, R. P. In situ nanoscale redox mapping using tip-enhanced Raman spectroscopy. Nano Lett. 19, 2106–2113 (2019).

    ADS  Google Scholar 

  188. Negri, P., Jacobs, K. T., Dada, O. O. & Schultz, Z. D. Ultrasensitive surface-enhanced Raman scattering flow detector using hydrodynamic focusing. Anal. Chem. 85, 10159–10166 (2013).

    Google Scholar 

  189. Jacobs, K. T. & Schultz, Z. D. Increased SERS detection efficiency for characterizing rare events in flow. Anal. Chem. 87, 8090–8095 (2015).

    Google Scholar 

  190. Zong, C., Chen, C.-J., Zhang, M., Wu, D.-Y. & Ren, B. Transient electrochemical surface-enhanced Raman spectroscopy: a millisecond time-resolved study of an electrochemical redox process. J. Am. Chem. Soc. 137, 11768–11774 (2015).

    Google Scholar 

  191. Lindquist, N. C., de Albuquerque, C. D. L., Sobral-Filho, R. G., Paci, I. & Brolo, A. G. High-speed imaging of surface-enhanced Raman scattering fluctuations from individual nanoparticles. Nat. Nanotechnol. 14, 981–987 (2019).

    ADS  Google Scholar 

  192. Stranahan, S. M. & Willets, K. A. Super-resolution optical imaging of single-molecule SERS hot spots. Nano Lett. 10, 3777–3784 (2010).

    ADS  Google Scholar 

  193. Titus, E. J., Weber, M. L., Stranahan, S. M. & Willets, K. A. Super-resolution SERS imaging beyond the single-molecule limit: an isotope-edited approach. Nano Lett. 12, 5103–5110 (2012).

    ADS  Google Scholar 

  194. Willets, K. A. Super-resolution imaging of SERS hot spots. Chem. Soc. Rev. 43, 3854–3864 (2014).

    Google Scholar 

  195. Le Ru, E. C., Etchegoin, P. G. & Meyer, M. Enhancement factor distribution around a single surface-enhanced Raman scattering hot spot and its relation to single molecule detection. J. Chem. Phys. 125, 204701 (2006).

    ADS  Google Scholar 

  196. Le Ru, E. C. & Etchegoin, P. G. Single-molecule surface-enhanced Raman spectroscopy. Annu. Rev. Phys. Chem. 63, 65–87 (2012).

    ADS  Google Scholar 

  197. Somorjai, G. A. & Li, Y. Introduction to Surface Chemistry and Catalysis Ch. 1 (Wiley, 2010).

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Acknowledgements

The authors thank S. Matthew for help in editing the manuscript before submission. The authors acknowledge financial support from the National Natural Science Foundation of China (grant nos 21633005, 21790354 and 21711530704), the Ministry of Science and Technology of China (grant no. 2016YFA0200601), the China Postdoctoral Science Foundation (grant no. 2017M622062) and the Natural Science Foundation of Fujian Province (grant no. 2016J05046).

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Glossary

Optical antenna

A device, typically made of a metal nanostructure or nanoparticles, that can efficiently couple the energy of free-space electromagnetic waves into a subwavelength region.

Optical cavity

An arrangement of mirrors that forms a standing wave for light of certain frequency, owing to the constructive and destructive interference of multiple reflected light.

Raman reporter molecules

Molecules with a large Raman cross section that can be used to report the presence of target molecules with small Raman cross sections, or molecules that are sensitive to the environment and can be used to monitor environmental changes.

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Wang, X., Huang, SC., Hu, S. et al. Fundamental understanding and applications of plasmon-enhanced Raman spectroscopy. Nat Rev Phys 2, 253–271 (2020). https://doi.org/10.1038/s42254-020-0171-y

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