TY - JOUR
T1 - Silica nanoparticles with thermally activated delayed fluorescence for live cell imaging
AU - Crucho, Carina I. C.
AU - Avó, João
AU - Nobuyasu, Roberto
AU - N. Pinto, Sandra
AU - Fernandes, Fábio
AU - Lima, João C.
AU - Berberan-Santos, Mário N.
AU - Dias, Fernando B.
N1 - Funding Information:
J. A. acknowledges Fundação para a Ciência e a Tecnologia (FCT, I.P.) for funding under grant SFRH/BPD/120599/2016 and project PTDC/QUI-QFI/32007/2017.
We also acknowledge Plataforma Portuguesa de Bioimagem (POCI-01-0145-FEDER-022122).
PY - 2020/4
Y1 - 2020/4
N2 - Thermally activated delayed fluorescence (TADF) has revolutionized the field of organic light emitting diodes owing to the possibility of harvesting non-emissive triplet states and converting them in emissive singlet states. This mechanism generates a long-lived delayed fluorescence component which can also be used in sensing oxygen concentration, measuring local temperature, or on imaging. Despite this strong potential, only recently TADF has emerged as a powerful tool to develop metal-free long-lived luminescent probes for imaging and sensing. The application of TADF molecules in aqueous and/or biological media requires specific structural features that allow complexation with biomolecules or enable emission in the aggregated state, in order to retain the delayed fluorescence that is characteristic of these compounds. Herein we demonstrate a facile method that maintains the optical properties of solvated dyes by dispersing TADF molecules in nanoparticles. TADF dye-doped silica nanoparticles are prepared using a modified fluorescein fluorophore. However, the strategy can be used with many other TADF dyes. The covalent grafting of the TADF emitter into the inorganic matrix effectively preserves and transfers the optical properties of the free dye into the luminescent nanomaterials. Importantly, the silica matrix is efficient in shielding the dye from solvent polarity effects and increases delayed fluorescence lifetime. The prepared nanoparticles are effectively internalized by human cells, even at low incubation concentrations, localizing primarily in the cytosol, enabling fluorescence microscopy imaging at low dye concentrations.
AB - Thermally activated delayed fluorescence (TADF) has revolutionized the field of organic light emitting diodes owing to the possibility of harvesting non-emissive triplet states and converting them in emissive singlet states. This mechanism generates a long-lived delayed fluorescence component which can also be used in sensing oxygen concentration, measuring local temperature, or on imaging. Despite this strong potential, only recently TADF has emerged as a powerful tool to develop metal-free long-lived luminescent probes for imaging and sensing. The application of TADF molecules in aqueous and/or biological media requires specific structural features that allow complexation with biomolecules or enable emission in the aggregated state, in order to retain the delayed fluorescence that is characteristic of these compounds. Herein we demonstrate a facile method that maintains the optical properties of solvated dyes by dispersing TADF molecules in nanoparticles. TADF dye-doped silica nanoparticles are prepared using a modified fluorescein fluorophore. However, the strategy can be used with many other TADF dyes. The covalent grafting of the TADF emitter into the inorganic matrix effectively preserves and transfers the optical properties of the free dye into the luminescent nanomaterials. Importantly, the silica matrix is efficient in shielding the dye from solvent polarity effects and increases delayed fluorescence lifetime. The prepared nanoparticles are effectively internalized by human cells, even at low incubation concentrations, localizing primarily in the cytosol, enabling fluorescence microscopy imaging at low dye concentrations.
KW - Confocal microscopy
KW - Silica nanoparticles
KW - Thermally-activated delayed fluorescence
UR - http://www.scopus.com/inward/record.url?scp=85076466735&partnerID=8YFLogxK
U2 - 10.1016/j.msec.2019.110528
DO - 10.1016/j.msec.2019.110528
M3 - Article
C2 - 32228970
AN - SCOPUS:85076466735
SN - 0928-4931
VL - 109
JO - Materials Science and Engineering C
JF - Materials Science and Engineering C
M1 - 110528
ER -