title: Visualization of molecular fluorescence point spread functions via remote excitation switching fluorescence microscopy.
abstract: The enhancement of molecular absorption, emission and scattering processes by coupling to surface plasmon polaritons on metallic nanoparticles is a key issue in plasmonics for applications in (bio)chemical sensing, light harvesting and photocatalysis. Nevertheless, the point spread functions for single-molecule emission near metallic nanoparticles remain difficult to characterize due to fluorophore photodegradation, background emission and scattering from the plasmonic structure. Here we overcome this problem by exciting fluorophores remotely using plasmons propagating along metallic nanowires. The experiments reveal a complex array of single-molecule fluorescence point spread functions that depend not only on nanowire dimensions but also on the position and orientation of the molecular transition dipole. This work has consequences for both single-molecule regime-sensing and super-resolution imaging involving metallic nanoparticles and opens the possibilities for fast size sorting of metallic nanoparticles, and for predicting molecular orientation and binding position on metallic nanoparticles via far-field optical imaging.
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Liang
authors: L
authors: Su
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Gang
authors: G
authors: Lu
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Bart
authors: B
authors: Kenens
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Susana
authors: S
authors: Rocha
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Eduard
authors: E
authors: Fron
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Haifeng
authors: H
authors: Yuan
authors: 1] IMEC, Kapeldreef 75, B-3001 Heverlee, Belgium [2] KU Leuven, Department of Physics and Astronomy, Celestijnenlaan 200D, B-3001 Heverlee, Belgium.
authors: Chang
authors: C
authors: Chen
authors: 1] IMEC, Kapeldreef 75, B-3001 Heverlee, Belgium [2] KU Leuven, Department of Physics and Astronomy, Celestijnenlaan 200D, B-3001 Heverlee, Belgium.
authors: Pol
authors: P
authors: Van Dorpe
authors: KU Leuven, Department of Microbial and Molecular Systems, Center for Surface Chemistry and Catalysis, Kasteelpark Arenberg 23, B-3001 Heverlee, Belgium.
authors: Maarten B J
authors: MB
authors: Roeffaers
authors: KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium.
authors: Hideaki
authors: H
authors: Mizuno
authors: 1] KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium [2] University of Copenhagen, Nano-Science Center/Department of Chemistry, Universitetsparken 5, 2100 Copenhagen, Denmark.
authors: Johan
authors: J
authors: Hofkens
authors: 1] ISIS &icFRC, Université de Strasbourg &CNRS UMR 7006, Strasbourg 67000, France [2] School of Chemistry and Bio21 Institute, University of Melbourne, Victoria 3010, Australia.
authors: James A
authors: JA
authors: Hutchison
authors: 1] KU Leuven, Department of Chemistry, Celestijnenlaan 200G-F, B-3001 Heverlee, Belgium [2] PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.
authors: Hiroshi
authors: H
authors: Uji-I