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S6 Denmark). We performed AFM imaging using extremely low tapping amplitudes(directly related to the tapping force) to minimize any mechanical deformations8. Fluorescent spectral microscopyFluorescent spectral microscopy was performed using 800 nm excitation from a diodelaser (Roithner Laser Technik, RLT80010MG). The laser beam is reflected via a dichroicbeam splitter (Chroma, Q850LPXXR) towards an oil-immersion objective (Nikon, PlanFluor 100 ×NA 1.3), which focuses the light onto the sample. The fluorescence light iscollected by the same objective and passes through the dichroic beam splitter. Byswitching a foldable mirror, the fluorescence light can be directed either towards a singlephoton counting avalanche photodiode (APD) (SPCM-AQR-14, Perkin ElmerOptoelectronics) or towards a custom designed prism-based spectrograph with singlemolecule sensitivity equipped with a liquid nitrogen-cooled CCD camera (Spec-10:100B, Princeton Instruments).References1Onclin, S.; Mulder, A.; Huskens, J.; Ravoo, B. J.; Reinhoudt, D. N.; Langmuir 2004, 20, 5460-5466.2Ludden, M. J. W.; Mulder, A.; Tampe, R.; Reinhoudt, D. N.; Huskens, J., AngewandteChemie-International Edition 2007, 46, (22), 4104-4107.3Ludden, M. J. W.; Peter, M.; Reinhoudt, D. N.; Huskens, J. Small 2006, 2, (10), 1192-1202.4Olsen, J. D.; Robert, B.; Siebert, A.; Bullough, P. A.; Hunter, C. N., Role of the c-terminal extrinsic region of the alpha polypeptide of the light-harvesting 2 complex ofRhodobacter sphaeroides: A domain swap study. Biochemistry 2003, 42, (51), 15114-15123.