Light upconverting soft particles: triplet–triplet annihilation in the phospholipid bilayer of self-assembled vesicles

Pozník, Michal; Faltermeier, Uwe; Dick, Bernhard; König, Burkhard

doi:10.1039/c6ra07666a

Cited by 17 publications

(15 citation statements)

References 24 publications

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“…The need to extend this phenomenon to water environment and to biological specimen triggered remarkable efforts in the preparation of TTA‐UC structures. Among them, active polymeric structures, ionogels, liposomes, different supramolecular approaches, oil in water microemulsions, dendrimers, micelles, and water dispersible nanoparticles and nanocapsules led to demonstration of the applicability of TTA‐UC both in vitro and in vivo, within the tissue transparency window …”

Section: Introductionmentioning

confidence: 99%

“…Very recently Yanai and co‐workers demonstrated that the synthesis and water phase self‐assembly of amphiphilic cationic acceptor molecules with anionic donor (sensitizer) molecules provides an efficient way to address the oxygen quenching issue by a purely supramolecular approach . Finally, König and co‐workers demonstrated efficient TTA‐UC in large unilamellar vesicles loaded with suitably functionalized diphenylanthracene derivatives as well as both PtOEP and a Ru bipyridine complex . Unfortunately, all of the aforementioned approaches require either the synthesis of specifically designed chromophores, the incorporation of organic solvents, or a complex multistep fabrication of appropriate nanovectors, and therefore they can be impractical in many cases.…”

Section: Introductionmentioning

confidence: 99%

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Self‐Assembled Dual Dye‐Doped Nanosized Micelles for High‐Contrast Up‐Conversion Bioimaging

Mattiello

Monguzzi

Pedrini

et al. 2016

Adv Funct Materials

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Sensitized triplet–triplet annihilation based photon up‐conversion (TTA‐UC) greatly improves the scope and applicability of fluorescence bioimaging by enabling anti‐Stokes detection at low powers, thus eliminating the background autofluorescence and limiting the potential damage of the living tissues. Here the authors present a facile, one‐step protocol to prepare dual dye‐doped, TTA‐UC active nanomicelles starting from the commercially available surfactant Kolliphor EL, a component of several FDA approved preparations. These nanosized micelles show an unprecedented up‐conversion yield of 6.5% under 0.1 W cm−2 excitation intensity in an aqueous, nondeaerated dispersion. The supramolecular architecture obtained preserves the embedded dyes from oxygen quenching, allowing satisfactory anti‐Stokes fluorescence imaging of 3T3 cells. This is the first example of efficient multicomponent up‐converters prepared using highly biocompatible materials approved by the international authority, paving the way for the development of new complex and multifunctional materials for advanced theranostics.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Self‐Assembled Dual Dye‐Doped Nanosized Micelles for High‐Contrast Up‐Conversion Bioimaging

Mattiello

Monguzzi

Pedrini

et al. 2016

Adv Funct Materials

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“…This way the sensitizer and annihilator are used more optimally while at the same time the energy transfer rates are increased due to the dense packing of the chromophores. Several examples exist and range from lipid bilayers [59][60][61] to using DNA as an assembly scaffold [62] . Associated to this is also encapsulation of the TTA-UC system into protective environments with the intent to be used in polar solvents like water which would increase the usability of TTA-UC in real life applications.…”

Section: Soft Systemsmentioning

confidence: 99%

Photon upconversion through triplet–triplet annihilation

Gray¹

2019

Photochemistry

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The sun is the only renewable energy source that can accommodate humanity's energy needs today and in the foreseeable future. The sunlight reaching the planet's surface is filtrated through the atmosphere, reducing its UV-light intensity in the 300-400 nm range, which indeed can be harmful to life as we know it in too large doses. However, many useful photoreactions require in practice such high-energy UV-photons, like the catalytic splitting of water to oxygen and hydrogen gas or molecular in-bond energy storage through isomerization to produce heat when reverting to the initial state. The efficiency of these applications could be improved with efficient conversion of low-energy visible to high-energy UV-light. One way to achieve this type of photon upconversion (UC) is through the process called Triplet-Triplet Annihilation (TTA) relying on the interaction between two molecules; a sensitizer and an annihilator. The sensitizer absorbs low energy visible photons as input and transfers that energy through Triplet Energy Transfer (TET) to an annihilator. Two triplet-excited annihilators can thereafter perform TTA, merging the energy equivalents of the two low-energy photons to produce one high-energy photon as output. This Thesis is focused on improving the known bimolecular UC system in fluid environment and approaching the ultimate goal of high efficiency UC in solid materials. In the fluid system I demonstrate the employment of thiol-and thioether-based compounds as scavengers for singlet excited oxygen with positive effect on UC efficiency and stability. In an attempt to aid future design and optimization of upconversion system components the anthracene is 9,10-substituted with electron withdrawing or donating groups while its TTA-UC function is evaluated revealing that substitution at para-positions leads to least perturbation of its spectroscopic properties. The ultimate goal is to achieve supramolecular TTA-UC systems capable of efficient intra-molecular TET and TTA processes and unhindered emission of the upconverted photons. As a first step, we focus on the intra-molecular TTA process with oligomers and dendrimers of 9,10-diphenyl anthracene (DPA) which display positive effects on UC efficiency in solid matrix. In the second step the focus is on the intra-molecular TET process where the sensitizerannihilator complexes are explored through Lewis base-acid coupling with orthogonal transition moments for minimum excited state short circuit effect. Additionally, kinetic simulations of the TTA-UC processes are conducted to aid understanding and optimization. Finally, one TTA-UC system is also applied to chemical in-bond energy storage.

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“…29,30,32,33 However, the essential requirements for TTA-UC, i.e., triplet energy transfer and annihilation processes, rely on the molecular diffusion of TTA-UC dyes ( Figure S3, Supporting Information), which are inevitably suppressed in these viscous environments. 32,33 The hydrophobic interior of aqueous micelles 34 and lipid membranes [35][36][37][38] has also been employed to dissolve hydrophobic TTA-UC dyes, where the similarly limited diffusion of chromophores in the interior of these molecular assemblies limits their performance.…”

Section: Introductionmentioning

confidence: 99%

Aqueous Photon Upconversion by Anionic Acceptors Self-Assembled on Cationic Bilayer Membranes with a Long Triplet Lifetime

et al. 2019

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Anionic 9,10-diphenylanthracene chromophores electrostatically bound to cationic, chiral bilayer membranes show ordered self-assembly in water. The integrity of the chromophore-accumulated aqueous bilayer membranes is ensured by multiple hydrogen-bond networks introduced in the bilayer, which allowed adaptive accommodation of the guest chromophores at the inner surface of the bilayer while maintaining their cohesive interactions. The regular chromophore alignment in the aqueous assembly is confirmed by differential scanning calorimetry, circular dichroism, and circularly polarized luminescence spectra. Excitonic migration of triplet energy occurs among the chromophores densely organized at the inner surface of the bilayer, which lead to triplet–triplet annihilation-based photon upconversion (TTA-UC). This acceptor-bilayer self-assemblies show a notably long triplet lifetime of 8.0 ms, which allows TTA-UC at sufficiently low excitation light intensity. These results demonstrate the usefulness of the simple electrostatic accumulation approach for TTA-UC chromophores where the suitable molecular design of the TTA-UC chromophore-integrated bilayer membranes plays a key role.

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Light upconverting soft particles: triplet–triplet annihilation in the phospholipid bilayer of self-assembled vesicles

Cited by 17 publications

References 24 publications

Self‐Assembled Dual Dye‐Doped Nanosized Micelles for High‐Contrast Up‐Conversion Bioimaging

Self‐Assembled Dual Dye‐Doped Nanosized Micelles for High‐Contrast Up‐Conversion Bioimaging

Photon upconversion through triplet–triplet annihilation

Aqueous Photon Upconversion by Anionic Acceptors Self-Assembled on Cationic Bilayer Membranes with a Long Triplet Lifetime

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