Junk M.J.N.,Max Planck lnstitut fur Polymerforschung |
Li W.,ETH Zurich |
Schluter A.D.,ETH Zurich |
Wegner G.,Max Planck lnstitut fur Polymerforschung |
And 4 more authors.
Angewandte Chemie - International Edition | Year: 2010
(Figure Presented) The collapse transition of thermoresponsive dendronized polymers was characterized on a molecular scale by CW EPR spectroscopy. Aggregation of the polymer is triggered by dynamic structural inhomogeneities of a few nanometers, and the dehydration of the polymer chains proceeds, despite the sharp phase transition, over a temperature interval of at least 30°C (see picture). © 2010 Wiley-VCH Verlag GmbH & Co. KCaA, Weinheim.
Cordes T.,Ludwig Maximilians University of Munich |
Cordes T.,University of Oxford |
Vogelsang J.,Ludwig Maximilians University of Munich |
Vogelsang J.,University of Texas at Austin |
And 7 more authors.
Journal of the American Chemical Society | Year: 2010
Dynamic developments in ultrasensitive and superresolution fluorescence microscopy call for improved fluorescence markers with increased photostability and new functionalities. We used single-molecule spectroscopy to study water-soluble perylene dicarboximide fluorophores (PDI), which were immobilized in aqueous buffer by attaching the fluorophore to DNA. Under these conditions bright fluorescence, comparable to that of single-molecule compatible organic fluorophores, is observed with homogeneous spectral and fluorescence decay time distributions. We additionally show how the fluorescence of the PDI can be controlled through photoinduced electron-transfer reactions by using different concentrations of reductants and oxidants, yielding either blinking or stable emission. We explain these properties by the redox potentials of PDI and the recently introduced ROXS (reducing and oxidizing system) concept. Finally, we evaluate how this fluorescence control of PDIs can be used for superresolution "Blink-Microscopy" in aqueous or organic media and more generally for single-molecule spectroscopy. © 2010 American Chemical Society.