Origin of simultaneous donor-acceptor emission in single molecules of peryleneimide-terrylenediimide labeled polyphenylene dendrimers.
Förster type resonance energy transfer (FRET) in donor-acceptor peryleneimide-terrylenediimide dendrimers has been examined at the single molecule level. Very efficient energy transfer between the donor and the acceptor prevent the detection of donor emission before photobleaching of the acceptor. Indeed, in solution, on exciting the donor, only acceptor emission is detected. However, at the single molecule level, an important fraction of the investigated individual molecules (about 10-15%) show simultaneous emission from both donor and acceptor chromophores. The effect becomes apparent mostly after photobleaching of the majority of donors. Single molecule photon flux correlation measurements in combination with computer simulations and a variety of excitation conditions were used to determine the contribution of an exciton blockade to this two-color emission. Two-color defocused wide-field imaging showed that the two-color emission goes hand in hand with an unfavorable orientation between one of the donors and the acceptor chromophore.
Melnikov
Sergey M
SM
Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium.
Yeow
Edwin K L
EK
Uji-i
Hiroshi
H
Cotlet
Mircea
M
Müllen
Klaus
K
De Schryver
Frans C
FC
Enderlein
Jörg
J
Hofkens
Johan
J
D001703:Biophysics / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D007091:Image Processing, Computer-Assisted; D007094:Imides / Q000737:chemistry*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence / Q000379:methods; D008956:Models, Chemical; D015233:Models, Statistical; D009010:Monte Carlo Method; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D017785:Photons; D011108:Polymers / Q000737:chemistry*; D011336:Probability; D013997:Time Factors
D007094:Imides; D011108:Polymers; C520054:peryleneimide-terrylenediimide; D010569:Perylene; C041325:polyphenylene sulfide