Collective Fluorescence Blinking in Linear J-Aggregates Assisted by Long-Distance Exciton Migration

Abstract

Fluorescence blinking corresponding to collective quenching of up to 100 dye monomers is reported for individual J-aggregates of a perylene bisimide (PBI) dye. This implies an exciton diffusion length up to 70 nm in these one-dimensional assemblies. The number of quenched monomers was directly measured by comparing the fluorescence brightness of the J-aggregates with that of noncoupled PBI molecules. This brightness analysis technique is useful for unraveling photophysical parameters of any individual fluorescent nanosystem.

Collective fluorescence switching of counterion-assembled dyes in polymer nanoparticles

“…Among the studied counterions, F5-TPB, being the bulkiest, the most hydrophobic and having the highest negative charge density at its surface due to its highly electronegative fluorines, is thought to be the best counterion to favour this ordering. Complete on/off switching can only be observed in systems that behave similar to a single exciton, namely single dye molecules 18 , quantum dots 19,40 , dye dendrimers 21,49 , J-aggregates 22 or single chains of conjugated polymers 20 . Here we obtained the first dye-doped NPs undergoing complete on/off switching due to collective dye behaviour, which can be realized even for ensembles of 500 dyes.…”

“…15). To further determine the number of fluorophores involved in the collective on/off switching, we measured the absolute number of fluorophores emitting in the on-state 22 by comparing the brightness of immobilized NPs to that of standard fluorescent polystyrene The steady-state anisotropy r ð Þ and residual anisotropy (r N ) are given in the inset. For 0.1 wt% R18/F5-TPB, the corresponding fit is given, and the residual anisotropy corresponds to the fitted value.…”

“…Collective behaviour is especially exemplified by on/off switching (also called blinking), a process normally observed for single emitters such as individual fluorophores 18 and quantum dots 19 . The phenomenon of blinking in conjugated polymers 20 , dendrimers 21 , photosynthetic centres 12 and J-aggregates 22 shows that due to ultrafast EET, up to 100 fluorophores could be collectively turned off by a single energy trap 20,22 . However, collective switching has never been reported for dye-doped NPs.…”

Exciton Level Structure and Dynamics in Tubular Porphyrin Aggregates

“…[5][6][7][8][9][10] In the presence of strong intermolecular coupling, as is the case for J-aggregates, the chromophores can act collectively (coherently) and potentially support faster energy transport. 4,7,[11][12][13][14][15] The Frenkel exciton, a collective excitation shared by many molecules, serves as the best description of the excited states of these molecular aggregates. 11,[16][17] Tubular aggregates formed by self-assembly of dye molecules represent one of the most promising constructs for biomimetic photosynthetic antenna systems.…”

Photon emission statistics and photon tracking in single-molecule spectroscopy of molecular aggregates: Dimers and trimers

“…ular systems. [25][26][27][28][29] SMS allows one to directly address single systems of interest in a -possibly-heterogeneous ensemble, thereby avoiding the ensemble averaging that necessarily takes place in bulk experiments and allowing one to look directly under the inhomogeneous line shapes measured in ensemble spectra. SMS experiments performed on single bacteriochlorophyll aggregates, 30 terylene dimers, 31 tetraphenoxy-perylene diimide trimers, 32 and single aggregates of amphi-pseudoisocyanine 33 have indeed revealed that interesting details on collective optical transitions are hidden underneath the ensemble average.…”