Photophysics of New Photostable Rylene Derivatives: Applications in Single‐Molecule Studies and Membrane Labelling

Abstract

Three new photostable rylene dyes for applications in single molecule studies and membrane labelling have been synthesized and their photophysical properties were characterized. These dyes differ in the number of polyethylene glycol (PEG) chains attached to the core structure which is either a perylene derivate or a terrylene derivate. One perylene and one terrylene dye is modified with two PEG chains, and another terrylene derivate has four PEG chains. The results show that the terrylene dye with four PEG chains (4-PEG-TDI) forms soluble nonfluorescing H-aggregates in water, so that the absorption bands are blue-shifted with respect to those of the fluorescing monomeric form. The presence of a surfactant such as Pluronic P123 leads to the disruption of the aggregates due to the formation of monomers in micelles and a strong increase in fluorescence. Application for labelling cell membranes can be considered for this dye since it adsorbs in a similar way as monomer to a lipid bilayer. Furthermore a single-molecule study of all three rylene dyes in polymeric films of PMMA showed excellent photostability with respect to photobleaching, far above the photostability of other common water-soluble dyes, such as Oxazine-1, Atto647N, Cy5, Alexa647 and Rhodamin6G. Especially 4-PEG-TDI seems to be a promising dye for membrane labelling with its high photostability.

Theoretical and experimental investigation on the intersystem crossing kinetics in benzothioxanthene imide luminophores, and their dependence on substituent effects

“…Rylene imide derivatives are a very intriguing subclass of extended conjugated dyes which have been thoroughly studied for various organic electronic applications, 1,2 such as electroluminescent devices, 3,4 field effect transistors, 5, 6 photovoltaics [7][8][9][10] or luminescent tags for bioimaging. [11][12][13] Their success mostly results from the interplay of outstanding spectroscopic properties such as high luminescence quantum yields, 14 a large range of structure dependent accessible emission wavelengths, 15 high thermal and photostability 16 and associated to a moderate synthetic cost compatible with large scale syntheses. 17,18 Within this rylene family, the benzothioxanthene imide derivatives (BTXI) constitute a largely overlooked class of chromophore, [19][20][21][22][23] especially when compared to perylene bisimide.…”

Synthesis and Self‐Assembly of Bay‐Substituted Perylene Diimide Gemini‐Type Surfactants as Off‐On Fluorescent Probes for Lipid Bilayers

“…Substituted perylene‐3,4:9,10‐tetracarboxylic diimides (PDIs) have attracted interest for a variety of applications, including organic electronics,1, 2, 3 single molecule spectroscopy4, 5, 6 and bioimaging 7, 8, 9. For bioimaging, fluorescent quenching of PDIs has been used to sense hydrophobicity changes such as in artificial and cellular bilayers 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.…”

Electronic Modulation of Terrylene Diimides Leading to Core‐Twisting, Tunable Emission and Intermolecular Interactions

“…The broadening of emission bands may be attributed to the twisting in the aromatic terrylene core. The fluorescence quantum yields obtained were 16 and 22 % for TDI‐Ph and TDI‐PhCN , respectively with respect to parent TDI (Φ = 90 %) as reference , . The emission from TDI‐PhNMe 2 was quenched, further supporting the CT transition from dimethylaminophenyl group to the TDI core.…”

“…Among larger RDIs, terrylene diimides (TDIs) have transpired as important dyes for single molecule spectroscopy studies, membrane labeling and enzyme tracking experiments because of their inherent higher absorption coefficients in the NIR region with high fluorescence quantum yields . TDIs also exhibit high thermal and photochemical stabilities, which makes them compatible for use in organic field‐effect transistors, photochromic switches, supramolecular self‐assemblies, and organic solar cell applications .…”