Two-photon absorption of polyfluorene aggregates stabilized by insulin amyloid fibrilsElectronic supplementary information (ESI) available. See DOI: 10.1039/c5ra08302h

We report on the photophysical and optical properties of a polyfluorene derivative (PFO) and its binding to the amyloid-forming protein insulin. The complexation is based on weak supramolecular interactions between amyloid fibrils and PFO in dissolved and aggregated forms. In particular, complexes of polyfluorene aggregates display sizeable two-photon absorption when stabilized by insulin fibril nanotemplates. We propose that a two-photon absorption enhancement mechanism is related to the combination of through-bond and through-space interactions of PFO. The findings reported here suggest that polyfluorene aggregates offer good nonlinear absorption properties and can be used as molecular markers for amyloid fibril recognition. We report on the photophysical and optical properties of a polyfluorene derivative (PFO) and its binding to the amyloid-forming protein insulin.