Ultra pseudo-Stokes shift near infrared dyes based on energy transfer

Han, Junyan; Engler, Anthony; Qi, Jianjun; Tung, Ching–Hsuan

doi:10.1016/j.tetlet.2012.11.060

Cited by 16 publications

(15 citation statements)

References 16 publications

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“…Additionally, the cyanine dye absorption wavelength is highly tunable based on methine chain length selection . The tunability, rapid synthesis, facile bioconjugation, intense molar absorptivities (ε), strong NIR emissions, and high molecular brightness (MB) values make this class of dyes attractive for further exploration as NIR emissive materials. , In addition to deeper NIR absorption and emission, dyes with large Stokes shifts and high quantum yields are in high demand. − For many applications, longer wavelength absorptions allow for access to differential dye properties relative to currently available dyes, and a larger Stokes shift provides dramatically higher resolution images in biological applications by reducing background signals. ,, Importantly, a significant MB is needed to give high resolution images with smaller amounts of emissive material . A balance between long wavelength use, Stokes shifts, and quantum yield must be struck for many functional materials in the NIR region, since the energy gap rule dictates diminished quantum yields as wavelengths increase. − Stokes shifts, which arise from molecular reorganizations, also tend to diminish quantum yields as the Stokes shift increases in magnitude.…”

Section: Introductionmentioning

confidence: 99%

Indolizine-Cyanine Dyes: Near Infrared Emissive Cyanine Dyes with Increased Stokes Shifts

et al. 2018

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Molecular engineering strategies designed to red-shift cyanine dye absorptions and emissions further into the near-infrared (NIR) spectral region are explored. Through the use of a novel donor group, indolizine, with varying cyanine bridge lengths, dye absorptions and emissions, were shifted deeper into the NIR region than common indoline-cyanines. Stokes shifts resulting from intramolecular steric interactions of up to ∼60 nm in many cases were observed and explained computationally. Molecular brightnesses of up to 5800 deep into the NIR region were observed. Structure–property relationships are explored for the six indolizine-cyanine dyes with varying cyanine bridge length and indolizine substituents showing broad absorption and emission tunability. The dyes are characterized by crystallography, and the photophysical properties are probed by varying solvent for absorption and emission studies. Computational data show involvement of the entire indolizine π-system during light absorption, which suggests these systems can be tunable even further into the NIR region through select derivatizations.

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Section: Introductionmentioning

confidence: 99%

Indolizine-Cyanine Dyes: Near Infrared Emissive Cyanine Dyes with Increased Stokes Shifts

et al. 2018

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“…This technique can use small organic molecules to absorb and emit photons in the therapeutic window of 650–1400 nm (depending on the tissue present), where the absorption and autofluorescence of the biological matrix are the lowest, leading to the deepest penetration depth. − Higher resolution in this region is desirable and is directly related to increased Stokes shifts (change in energy between absorption and emission curves), high fluorescence quantum yields (ratio of the number of photons emitted to the number of photons absorbed), and absorption as well as emission within the therapeutic window. Materials with these properties could offer new advances in emissive material applications such as biological imaging. − One of the most intriguing dyes for imaging applications is based on a donor–acceptor–donor (D–A–D) design with a benzobisthiadiazole acceptor and two triphenylamine donor groups (CH1055-PEG) which emits in the NIR II window (Figure ); however, the fluorescence quantum yield can still be improved (ϕ = 0.3%) . Further understanding of the fundamental photophysical properties of NIR conjugated systems is needed to rationally design future generations of applied materials with tailored emissive properties for numerous applications, including biological imaging.…”

Section: Introductionmentioning

confidence: 99%

Near-Infrared Fluorescent Thienothiadiazole Dyes with Large Stokes Shifts and High Photostability

et al. 2017

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A series of near-infrared (NIR) organic emissive materials were synthesized and the photophysical properties analyzed. The donor-acceptor-donor materials were designed with thienopyrazine and thienothiadiazole acceptor groups with thiophene-, furan-, and triphenylamine-based donor groups. The absorption and emission spectra were found to be widely tunable on the basis of the donor and acceptor groups selected. Computational analysis confirms these materials undergo an intramolecular charge-transfer event upon photoexcitation. Large Stokes shifts of ∼150 nm were observed and rationalized by computational analysis of geometry changes in the excited state. Fluorescence studies on the dye series reveal maximum peak emission wavelengths near 900 nm and a quantum yield exceeding 16% for 4,6-bis(2-thienyl)thieno[3,4-c][1,2,5]thiadiazole. Additionally, several dyes were found to have reasonable quantum yields within this NIR region (>1%), with emission wavelengths reaching 1000 nm at the emission curve onset. Photostability studies were conducted on these materials in an ambient oxygen environment, revealing excellent stability in the presence of oxygen from all the dyes studied relative to a benchmark cyanine dye (ICG) during photoexcitation with exceptional photostability from the 4,6-bis(5'-dodecyl-[2,2'-bithiophene]-5-yl)thieno[3,4-c][1,2,5]thiadiazole derivative.

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“…Covalent coupling of two fluorophores (one acting as highly absorbing antenna and another as long fluorescence lifetime emitter) yields an efficient Forster resonance energy transfer (FRET) pair. Even though the coupling of two or more fluorescent dyes in FRET dyads or triads is common in the literature as an approach to investigate energy transfer pathways, 30−34 increase the Stokes shift of the fluorescent probe 35,36 or brightness of phosphorescent lanthanide complexes, 37 to our knowledge this is the first time a dyad was specifically synthesized to combine a high absorbing antenna with a long fluorescence lifetime organic acceptor dye (Figure 1, insert). By choosing the right pair of organic dyes and appropriate linker, a system with efficient energy transfer, outcompeting the other deactivation pathways in the antenna, should be possible to achieve.…”

Section: ■ Introductionmentioning

confidence: 99%

Rational Design of Bright Long Fluorescence Lifetime Dyad Fluorophores for Single Molecule Imaging and Detection

et al. 2021

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Increasing demand for detecting single molecules in challenging environments has raised the bar for the fluorophores used. To achieve better resolution and/or contrast in fluorescence microscopy, it is now essential to use bright and stable dyes with tailored photophysical properties. While long fluorescence lifetime fluorophores offer many advantages in time-resolved imaging, their inherently lower molar absorption coefficient has limited applications in single molecule imaging. Here we propose a generic approach to prepare bright, long fluorescence lifetime dyad fluorophores comprising an absorbing antenna chromophore with high absorption coefficient linked to an acceptor emitter with a long fluorescence lifetime. We introduce a dyad consisting of a perylene antenna and a triangulenium emitter with 100% energy transfer from donor to acceptor. The dyad retained the long fluorescence lifetime (∼17 ns) and high quantum yield (75%) of the triangulenium emitter, while the perylene antenna increased the molar absorption coefficient (up to 5 times) in comparison to the free triangulenium dye. These triangulenium based dyads with significantly improved brightness can now be detected at the single molecule level and easily discriminated from bright autofluorescence by time-gated and other lifetime-based detection schemes.

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Ultra pseudo-Stokes shift near infrared dyes based on energy transfer

Cited by 16 publications

References 16 publications

Indolizine-Cyanine Dyes: Near Infrared Emissive Cyanine Dyes with Increased Stokes Shifts

Indolizine-Cyanine Dyes: Near Infrared Emissive Cyanine Dyes with Increased Stokes Shifts

Near-Infrared Fluorescent Thienothiadiazole Dyes with Large Stokes Shifts and High Photostability

Rational Design of Bright Long Fluorescence Lifetime Dyad Fluorophores for Single Molecule Imaging and Detection

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