Exploiting Fast Exciton Diffusion in Dye-Doped Polymer Nanoparticles to Engineer Efficient Photoswitching.
Photoswitching of bright fluorescent nanoparticles opens new possibilities for bioimaging with superior temporal and spatial resolution. However, efficient photoswitching of nanoparticles is hard to achieve using Förster resonance energy transfer (FRET) to a photochromic dye, because the particle size is usually larger than the Förster radius. Here, we propose to exploit the exciton diffusion within the FRET donor dyes to boost photoswitching efficiency in dye-doped polymer nanoparticles. To this end, we utilized bulky hydrophobic counterions that prevent self-quenching and favor communication of octadecyl rhodamine B dyes inside a polymer matrix of poly(D,L-lactide-co-glycolide). Among tested counterions, only perfluorinated tetraphenylborate that favors the exciton diffusion enables high photoswitching efficiency (on/off ratio ∼20). The switching improves with donor dye loading and requires only 0.1-0.3 wt % of a diphenylethene photochromic dye. Our nanoparticles were validated both in solution and at the single-particle level. The proposed concept paves the way to new efficient photoswitchable nanomaterials.
†Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 Illkirch Cedex, France.
Kateryna
K
Trofymchuk
‡Dipartimento di Chimica "Giacomo Ciamician", Università degli Studi di Bologna, via Selmi 2, 40126 Bologna, Italy.
Luca
L
Prodi
†Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 Illkirch Cedex, France.
Andreas
A
Reisch
†Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 Illkirch Cedex, France.
Yves
Y
Mély
§Organic Chemistry I, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany.
Kai
K
Altenhöner
§Organic Chemistry I, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany.
Jochen
J
Mattay
†Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 Illkirch Cedex, France.
Andrey S
AS
Klymchenko
D004058:Diffusion; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D019344:Lactic Acid / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012235:Rhodamines / Q000737:chemistry; D013775:Tetraphenylborate / Q000737:chemistry
D005456:Fluorescent Dyes; D012235:Rhodamines; C425723:octadecylrhodamine B; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D013775:Tetraphenylborate
PLGA polymer; bulky hydrophobic counterions; energy transfer; exciton diffusion; fluorescent nanoparticles; photochromic dye; single-particle microscopy