| 1. |
- Miguel-Blanco, Celia, et al.
(författare)
-
The antimalarial efficacy and mechanism of resistance of the novel chemotype DDD01034957
- 2021
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- New antimalarial therapeutics are needed to ensure that malaria cases continue to be driven down, as both emerging parasite resistance to frontline chemotherapies and mosquito resistance to current insecticides threaten control programmes. Plasmodium, the apicomplexan parasite responsible for malaria, causes disease pathology through repeated cycles of invasion and replication within host erythrocytes (the asexual cycle). Antimalarial drugs primarily target this cycle, seeking to reduce parasite burden within the host as fast as possible and to supress recrudescence for as long as possible. Intense phenotypic drug screening efforts have identified a number of promising new antimalarial molecules. Particularly important is the identification of compounds with new modes of action within the parasite to combat existing drug resistance and suitable for formulation of efficacious combination therapies. Here we detail the antimalarial properties of DDD01034957—a novel antimalarial molecule which is fast-acting and potent against drug resistant strains in vitro, shows activity in vivo, and possesses a resistance mechanism linked to the membrane transporter PfABCI3. These data support further medicinal chemistry lead-optimization of DDD01034957 as a novel antimalarial chemical class and provide new insights to further reduce in vivo metabolic clearance.
|
|
| 2. |
- Wan, Li, et al.
(författare)
-
Engineering the sign of circularly polarized emission in achiral polymer - chiral small molecule blends as a function of blend ratio
- 2022
-
Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 10:13, s. 5168-5172
-
Tidskriftsartikel (refereegranskat)abstract
- Circularly polarized organic light-emitting diodes (CP-OLEDs) that demonstrate both state-of-the-art efficiency and strongly circularly polarized (CP) electroluminescence have proved a considerable technical challenge. Furthermore, multiple factors - from film thickness to device structure - have been shown to influence the sign of the emitted CP light, independent of the handedness (absolute stereochemistry) of the chiral emitter. Here we report CP-OLEDs using a blend of poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2) and a chiral small molecule additive (1-aza[6]helicene, aza[6]H). We demonstrate CP-OLEDs with an impressive electroluminescence dissymmetry (g(EL)) > 0.3 and a current efficiency of 0.53 cd A(-1) and brightness of 3023 cd m(-2). While at low aza[6]H loadings, F8T2 blends are consistent with previous observations of CP dissymetric inversion as a function of film thickness/excitation mode, a higher loading of aza[6]H (similar to 40 wt%) removes such dependencies while retaining excellent g-factors. The materials disclosed will allow for further mechanistic studies of chiral polymeric materials and provide new opportunities for chiroptical optimisation in films and devices.
|
|
| 3. |
- Yan, Hao, et al.
(författare)
-
Enhancing hole carrier injection via low electrochemical doping on circularly polarized polymer light-emitting diodes
- 2022
-
Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 10:25, s. 9512-9520
-
Tidskriftsartikel (refereegranskat)abstract
- Circularly polarized electroluminescence (CP-EL) from a blend system of chiral small-molecule additives and device optimised achiral pi-conjugated polymers (pi-CPs) is of great interest for next-generation display technologies. However, CP polymer light-emitting diodes can suffer from unbalanced charge transport and unfavorable energetics between chiral additives and achiral polymers, which can limit the efficiency of charge injection and device performance. Herein, we demonstrate the use of a small amount of chemcially modified electrochemical doping agent (EDA, 1.5 wt%) to control such limitations. The EDA with a long cationic alkyl chain enables strong hydrophobicity and stable electrochemical doping of achiral pi-CP F8BT in F8BT:aza[6]H blends, which allows for better charge injection and balance. This leads to improved device performance while maintaining highly dissymmetric electroluminescence (g(EL) similar to 0.50@580 nm) and an inverted dissymmetry factor (g(EL) = -0.65@525 nm). These findings indicate that EDAs may provide a simple approach to improve the performance of CP optoelectronic devices.
|
|
| 4. |
- Liu, Tianjun, et al.
(författare)
-
High Responsivity Circular Polarized Light Detectors based on Quasi Two-Dimensional Chiral Perovskite Films
- 2022
-
Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 16:2, s. 2682-2689
-
Tidskriftsartikel (refereegranskat)abstract
- Circularly polarized light (CPL) has considerable technological potential, from quantum computing to bioimaging. To maximize the opportunity, high performance photodetectors that can directly distinguish left-handed and right-handed circularly polarized light are needed. Hybrid organic- inorganic perovskites containing chiral organic ligands are an emerging candidate for the active material in CPL photo-detecting devices, but current studies suggest there to be a trade-off between the ability to differentially absorb CPL and photocurrent responsivity in chiral perovskites devices. Here, we report a CPL detector based on quasi two-dimensional (quasi-2D) chiral perovskite films. We find it is possible to generate materials where the circular dichroism (CD) is comparable in both 2D and quasi-2D films, while the responsivity of the photodetector improves for the latter. Given this, we are able to showcase a CPL photodetector that exhibits both a high dissymmetry factor of 0.15 and a high responsivity of 15.7 A W-1. We believe our data further advocates the potential of chiral perovskites in CPL-dependent photonic technologies.
|
|
| 5. |
- Tyagi, Gunjan, et al.
(författare)
-
Light Responsiveness and Assembly of Arylazopyrazole-Based Surfactants in Neat and Mixed CTAB Micelles
- 2022
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863. ; 2:12, s. 2670-2677
-
Tidskriftsartikel (refereegranskat)abstract
- The self-assembly of an arylazopyrazole-based photosurfactant (PS), based on cetyltrimethylammonium bromide (CTAB), and its mixed micelle formation with CTAB in aqueous solution was investigated by small angle neutron and X-ray scattering (SANS/SAXS) and UV-vis absorption spectroscopy. Upon UV light exposure, PS photoisomerizes from E-PS (trans) to Z-PS (cis), which transforms oblate ellipsoidal micelles into smaller, spherical micelles with larger shell thickness. Doping PS with CTAB resulted in mixed micelle formation at all stoichiometries and conditions investigated; employing selectively deuterated PS, a monotonic variation in scattering length density and dimensions of the micellar core and shell is observed for all contrasts. The concentration- and irradiance-dependence of the E to Z configurational transition was established in both neat and mixed micelles. A liposome dye release assay establishes the enhanced efficacy of photosurfactants at membrane disruption, with E-PS exhibiting a 4-fold and Z-PS a 10-fold increase in fluorescence signal with respect to pure CTAB. Our findings pave the way for external triggering and modulation of the wide range of CTAB-based biomedical and material applications.
|
|
| 6. |
- Wan, Li, et al.
(författare)
-
Anomalous circularly polarized light emission in organic light-emitting diodes caused by orbital-momentum locking
- 2023
-
Ingår i: Nature Photonics. - : NATURE PORTFOLIO. - 1749-4885 .- 1749-4893. ; 17, s. 193-199
-
Tidskriftsartikel (refereegranskat)abstract
- Chiral circularly polarized (CP) light is central to many photonic technologies, from the optical communication of spin information to novel display and imaging technologies. As such, there has been significant effort in the development of chiral emissive materials that enable the emission of strongly dissymmetric CP light from organic light-emitting diodes (OLEDs). It has been widely accepted that the molecular chirality of the active layer determines the favoured light handedness of the CP emission in such devices, regardless of the light-emitting direction. Here we discover that, unconventionally, oppositely propagating CP light exhibits opposite handedness, and reversing the current flow in OLEDs also switches the handedness of the emitted CP light. This direction-dependent CP emission boosts the net polarization rate by orders of magnitude by resolving an established issue in CP-OLEDs, where the CP light reflected by the back electrode typically erodes the measured dissymmetry. Through detailed theoretical analysis, we assign this anomalous CP emission to a ubiquitous topological electronic property in chiral materials, namely orbital-momentum locking. Our work paves the way to design new chiroptoelectronic devices and probes the close connections between chiral materials, topological electrons and CP light in the quantum regime.
|
|
