| 1. |
- Appelqvist, Hanna, et al.
(författare)
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Specific Imaging of Intracellular Lipid Droplets Using a Benzothiadiazole Derivative with Solvatochromic Properties
- 2017
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Ingår i: Bioconjugate Chemistry. - : American Chemical Society (ACS). - 1043-1802 .- 1520-4812. ; 28:5, s. 1363-1370
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Tidskriftsartikel (refereegranskat)abstract
- Altered lipid metabolism and extensive lipid storage in cells have been associated with various medical disorders, including cancer. The development of fluorescent probes that specifically accumulate in lipid deposits is therefore of great interest in order to study pathological processes that are linked to dysregulated lipogenesis. In the present study, we present a small fluorescent benzothiadiazole dye that specifically stains lipid droplets in living and fixated cells. The photophysical characterization of the probe revealed strong solvatochromic behavior, large Stokes shifts, and high fluorescent quantum yields in hydrophobic solvents. In addition, the fluorophore exhibits a nontoxic profile and a high signal-to-noise ratio in cells (i.e., lipid droplets vs cytosol), which make it an excellent candidate for studying lipid biology using confocal fluorescent microscopy.
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| 2. |
- Kushwaha, Khushbu, et al.
(författare)
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A Record Chromophore Density in High-Entropy Liquids of Two Low-Melting Perylenes: A New Strategy for Liquid Chromophores
- 2019
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Ingår i: Advanced Science. - : Wiley. - 2198-3844. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Liquid chromophores constitute a rare but intriguing class of molecules that are in high demand for the design of luminescent inks, liquid semiconductors, and solar energy storage materials. The most common way to achieve liquid chromophores involves the introduction of long alkyl chains, which, however, significantly reduces the chromophore density. Here, strategy is presented that allows for the preparation of liquid chromophores with a minimal increase in molecular weight, using the important class of perylenes as an example. Two synergistic effects are harnessed: (1) the judicious positioning of short alkyl substituents, and (2) equimolar mixing, which in unison results in a liquid material. A series of 1-alkyl perylene derivatives is synthesized and it is found that short ethyl or butyl chains reduce the melting temperature from 278 degrees C to as little as 70 degrees C. Then, two low-melting derivatives are mixed, which results in materials that do not crystallize due to the increased configurational entropy of the system. As a result, liquid chromophores with the lowest reported molecular weight increase compared to the neat chromophore are obtained. The mixing strategy is readily applicable to other pi-conjugated systems and, hence, promises to yield a wide range of low molecular weight liquid chromophores.
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| 3. |
- Stranius, Kati, et al.
(författare)
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Determining the Photoisomerization Quantum Yield of Photoswitchable Molecules in Solution and in the Solid State
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Photoswitchable molecules are able to isomerize between two metastable forms through light stimuli. Originally being studied by photochemists, this type of molecule has now found a wide range of applications within physics, chemistry and biology. The extensive usage of photochromic molecules is due to the two isomers having fundamentally different physical and chemical properties. The most important attribute of a photoswitch is the photoisomerization quantum yield, which defines the efficiency of the photoisomerization event. Here we show how to determine the photoisomerization quantum yield in the solid state and in solution when taking thermal processes into account. The described method together with provided software allows for rapid and accurate determination of the isomerization process for this important class of molecules.
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| 4. |
- Stranius, Kati, et al.
(författare)
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Selective manipulation of electronically excited states through strong light-matter interactions
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Strong coupling between light and matter leads to the spontaneous formation of hybrid light-matter states, having different energies than the uncoupled states. This opens up for new ways of modifying the energy landscape of molecules without changing their atoms or structure. Heavy metal-free organic light emitting diodes (OLED) use reversed intersystem crossing (RISC) to harvest light from excited triplet states. This is a slow process, thus increasing the rate of RISC could potentially enhance OLED performance. Here we demonstrate selective coupling of the excited singlet state of Erythrosine B without perturbing the energy level of a nearby triplet state. The coupling reduces the triplet-singlet energy gap, leading to a four-time enhancement of the triplet decay rate, most likely due to an enhanced rate of RISC. Furthermore, we anticipate that strong coupling can be used to create energy-inverted molecular systems having a singlet ground and lowest excited state.
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