Fluorinated counterion-enhanced emission of rhodamine aggregates: ultrabright nanoparticles for bioimaging and light-harvesting.
The key to ultrabright fluorescent nanomaterials is the control of dye emission in the aggregated state. Here, lipophilic rhodamine B derivatives are assembled into nanoparticles (NPs) using tetraphenylborate counterions with varied fluorination levels that should tune the short-range dye ordering. Counterion fluorination is found to drastically enhance the emission characteristics of these NPs. Highly fluorinated counterions produce 10-20 nm NPs containing >300 rhodamine dyes with a fluorescence quantum yield of 40-60% and a remarkably narrow emission band (34 nm), whereas, for other counterions, aggregation caused quenching with a weak broad-band emission is observed. NPs with the most fluorinated counterion (48 fluorines) are ∼40-fold brighter than quantum dots (QD585 at 532 nm excitation) in single-molecule microscopy, showing improved photostability and suppressed blinking. Due to exciton diffusion, revealed by fluorescence anisotropy, these NPs are efficient FRET donors to single cyanine-5 acceptors with a light-harvesting antenna effect reaching 200. Finally, NPs with the most fluorinated counterion are rather stable after entry into living cells, in contrast to their less fluorinated analogue. Thus, the present work shows the crucial role of counterion fluorination in achieving high fluorescence brightness and photostability, narrow-band emission, efficient energy transfer and high intracellular stability of nanomaterials for light harvesting and bioimaging applications.
Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France. andrey.klymchenko@unistra.fr and Organic Chemistry Department, Chemistry Faculty, Taras Shevchenko National University of Kyiv, 01601 Kyiv, Ukraine.
Ievgen
I
Shulov
Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France. andrey.klymchenko@unistra.fr and Department of Biophysics, School of Medicine, Istanbul Medeniyet University, 34700 Istanbul, Turkey.
Sule
S
Oncul
Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France. andrey.klymchenko@unistra.fr.
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. andrey.klymchenko@unistra.fr.
Youri
Y
Arntz
Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France. andrey.klymchenko@unistra.fr.
Mayeul
M
Collot
Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France. andrey.klymchenko@unistra.fr.
Yves
Y
Mely
Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France. andrey.klymchenko@unistra.fr.
Andrey S
AS
Klymchenko
D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006367:HeLa Cells; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry / Q000494:pharmacology; D045663:Quantum Dots / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry / Q000494:pharmacology
D006845:Hydrocarbons, Fluorinated; D012235:Rhodamines