Impact of local compressive stress on the optical transitions of single organic dye molecules


The ability to mechanically control the optical properties of individual molecules is a grand challenge in nanoscience and could enable the manipulation of chemical reactivity at the single-molecule level. In the past, light has been used to alter the emission wavelength of individual molecules1 or modulate the energy transfer quantum yield between them2. Furthermore, tensile stress has been applied to study the force dependence of protein folding/unfolding3,4,5 and of the chemistry and photochemistry of single molecules6,7,8,9, although in these mechanical experiments the strength of the weakest bond limits the amount of applicable force. Here, we show that compressive stress modifies the photophysical properties of individual dye molecules. We use an atomic force microscope tip to prod individual molecules adsorbed on a surface and follow the effect of the applied force on the electronic states of the molecule by fluorescence spectroscopy. Applying a localized compressive force on an isolated molecule induces a stress that is redistributed throughout the structure. Accordingly, we observe reversible spectral shifts and even shifts that persist after retracting the microscope tip, which we attribute to transitions to metastable states. Using quantum-mechanical calculations, we show that these photophysical changes can be associated with transitions among the different possible conformers of the adsorbed molecule.

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Figure 1: Simultaneous AFM and CFM experiment.
Figure 2: Structure and optical spectra of TDI–4PDI.
Figure 3: Force–distance experiments on single TDI–4PDI molecules.
Figure 4: Force-induced transitions into metastable states.
Figure 5: Force–spectral shift correlation function Ct).


  1. 1

    Kulzer, F., Kummer, S., Matzke, R., Bräuchle, C. & Basché, T. Single-molecule optical switching of terrylene in p-terphenyl. Nature 387, 688–691 (1997).

  2. 2

    Irie, M., Fukaminato, T., Sasaki, T., Tamai, N. & Kawai, T. A digital fluorescent molecular photoswitch. Nature 420, 759–760 (2002).

  3. 3

    Rief, M., Gautel, M., Oesterhelt, F., Fernandez, J. M. & Gaub, H. E. Reversible unfolding of individual titin immunoglobulin domains by AFM. Science 276, 1109–1112 (1997).

  4. 4

    Lee, G. et al. Nanospring behaviour of ankyrin repeats. Nature 440, 246–249 (2006).

  5. 5

    Clausen-Schaumann, H., Seitz, M., Krautbauer, R. & Gaub, H. E. Force spectroscopy with single bio-molecules. Curr. Opin. Chem. Biol. 4, 524–530 (2000).

  6. 6

    Lenhardt, J. M. et al. Trapping a diradical transition state by mechanochemical polymer extension. Science 329, 1057–1060 (2010).

  7. 7

    Akbulatov, S., Tian, Y. & Boulatov, R. Force–reactivity property of a single monomer is sufficient to predict the micromechanical behavior of its polymer. J. Am. Chem. Soc. 134, 7620–7623 (2012).

  8. 8

    Liang, J. & Fernández, J. M. Mechanochemistry: one bond at a time. ACS Nano 3, 1628–1645 (2009).

  9. 9

    Hugel, T. et al. Single-molecule optomechanical cycle. Science 296, 1103–1106 (2002).

  10. 10

    Sarkar, A., Robertson, R. B. & Fernandez, J. M. Simultaneous atomic force microscope and fluorescence measurements of protein unfolding using a calibrated evanescent wave. Proc. Natl Acad. Sci. USA 101, 12882–12886 (2004).

  11. 11

    Gaiduk, A. et al. Fluorescence detection with high time resolution: from optical microscopy to simultaneous force and fluorescence spectroscopy. Microsc. Res. Tech. 70, 433–441 (2007).

  12. 12

    Kodama, T., Ohtani, H., Arakawa, H. & Ikai, A. Mechanical perturbation-induced fluorescence change of green fluorescent protein. Appl. Phys. Lett. 86, 043901 (2005).

  13. 13

    Kellermayer, M. S. Z. et al. Spatially and temporally synchronized atomic force and total internal reflection fluorescence microscopy for imaging and manipulating cells and biomolecules. Biophys. J. 91, 2665–2677 (2006).

  14. 14

    Gumpp, H. et al. Triggering enzymatic activity with force. Nano Lett. 9, 3290–3295 (2009).

  15. 15

    He, Y., Lu, M., Cao, J. & Lu, H. P. Manipulating protein conformations by single-molecule AFM–FRET nanoscopy. ACS Nano 6, 1221–1229 (2012).

  16. 16

    Schweitzer, G. et al. Intramolecular directional energy transfer processes in dendrimers containing perylene and terrylene chromophores. J. Phys. Chem. A 107, 3199–3207 (2003).

  17. 17

    Hofkens, J. et al. Conformational rearrangements in and twisting of a single molecule. Chem. Phys. Lett. 333, 255–263 (2001).

  18. 18

    Kowerko, D., Schuster, J. & von Borczyskowski, C. Restricted conformation dynamics of single functionalized perylene bisimide molecules on SiO2 surfaces and in thin polymer films. Mol. Phys. 107, 1911–1921 (2009).

  19. 19

    Butt, H. J., Cappella, B. & Kappl, M. Force measurements with the atomic force microscope: technique, interpretation and applications. Surf. Sci. Rep. 59, 1–152 (2005).

  20. 20

    Ebenstein, Y., Yoskovitz, E., Costi, R., Aharoni, A. & Banin, U. Interaction of scanning probes with semiconductor nanocrystals; physical mechanism and basis for near-field optical imaging. J. Phys. Chem. A 110, 8297–8303 (2006).

  21. 21

    Röhrig, U. F., Troppmann, U. & Frank, I. Organic chromophores under tensile stress. Chem. Phys. 289, 381–388 (2003).

  22. 22

    Marawske, S. et al. Fluorophores as optical sensors for local forces. ChemPhysChem 10, 2041–2048 (2009).

  23. 23

    Kobayashi, H., Hirata, S. & Vacha, M. Mechanical manipulation of photophysical properties of single conjugated polymer nanoparticles. J. Phys. Chem. Lett. 4, 2591–2596 (2013).

  24. 24

    Baer, B. J. & Chronister, E. L. Inhomogeneous spectral broadening in pentacene doped para-terphenyl crystals at high pressure and low temperature. Chem. Phys. 185, 385–391 (1994).

  25. 25

    Müller, A., Richter, W. & Kador, L. Pressure effects on single molecules of terrylene in p-terphenyl. Chem. Phys. Lett. 241, 547–554 (1995).

  26. 26

    Iwamoto, T., Kurita, A. & Kushida, T. Pressure effects on single-molecule spectra of terrylene in hexadecane. Chem. Phys. Lett. 284, 147–152 (1998).

  27. 27

    Davis, D. A. et al. Force-induced activation of covalent bonds in mechanoresponsive polymeric materials. Nature 459, 68–72 (2009).

  28. 28

    Brantley, J. N., Wiggins, K. M. & Bielawski, C. W. Unclicking the click: mechanically facilitated 1,3-dipolar cycloreversions. Science 333, 1606–1609 (2011).

  29. 29

    Becke, A. D. Density-functional exchange-energy approximation with correct asymptotic behavior. Phys. Rev. A 38, 3098–3100 (1988).

  30. 30

    Schäfer, A., Horn, H. & Ahlrichs, R. Fully optimized contracted Gaussian basis sets for atoms Li to Kr. J. Chem. Phys. 97, 2571–2577 (1992).

  31. 31

    Becke, A. D. A new mixing of Hartree–Fock and local density-functional theories. J. Chem. Phys. 98, 1372–1377 (1993).

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S.S. acknowledges support from the Deutsche Forschungsgemeinschaft (IRTG 1404).

Author information

S.S. performed the experiments and analysed the data. G.H. and T.B. designed and supervised the research. Synthesis and chemical analysis of TDI–4PDI were performed by I.O. and K.M. DFT calculations were performed by G.D. The experimental set-up was built by G.H. The manuscript was written by G.H., S.S. and T.B.

Correspondence to Gerald Hinze or Thomas Basché.

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Stöttinger, S., Hinze, G., Diezemann, G. et al. Impact of local compressive stress on the optical transitions of single organic dye molecules. Nature Nanotech 9, 182–186 (2014).

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