26
|
Abstract
Cell expansion is typically a long and labor-intensive step in CAR-T cell manufacture. The Xuri Cell Expansion System (CES) W25 semiautomates this step while functionally closing the process. Cells for autologous or allogeneic cell therapies are cultured inside a single-use Xuri Cellbag™ bioreactor. Wave-induced agitation, performed by a rocking Base Unit, transfers gas and mixes the culture. The integral UNICORN™ software allows customization of culture conditions and media perfusion schedules. Culture volumes can range from 300 mL to 25 L, making the Xuri CES W25 system suitable for both scale-up and scale-out manufacturing processes. CAR-T cell therapies have been successfully generated using the Xuri CES W25 system, which reduces manual labor compared with static culturing methods. This chapter details how to initiate a culture, install the Xuri CES W25, and install a 2 L Cellbag bioreactor. Protocols on inoculation, monitoring, and sampling are also outlined in this chapter.
Collapse
|
27
|
Xu Y, Zhou J, Smith TA. Time-resolved emission microscopy of light-induced aggregation of luminescent polymers. Methods Appl Fluoresc 2019; 8:014006. [PMID: 31747653 DOI: 10.1088/2050-6120/ab5976] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Photon pressure has been used to induce the aggregation from solution of a series of photoluminescent conjugated polyelectrolytes containing tetraphenylethene units. These polymers show steady-state and time-resolved emission properties that are dependent on the local chromophore environment that can be influenced by the degree of intra- and inter-molecular interactions, which enables the photoaggregation process to be monitored by time-resolved fluorescence imaging techniques. Structural differences in the polymer lead to variations in the photo-induced aggregation behaviour.
Collapse
|
28
|
Yu MN, Lin JY, Li YX, Soleimaninejad H, Ou CJ, Bai LB, Liu B, Liu W, Wei Q, Bo YF, Smith TA, Dunstan DE, Ghiggino KP, Xie LH, Xu CX, Bradley DD, Huang W. Emission Enhanced and Stabilized by Stereoisomeric Strategy in Hierarchical Uniform Supramolecular Framework. Chem 2019. [DOI: 10.1016/j.chempr.2019.06.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
29
|
Soleimaninejad H, Ghiggino KP, Smith TA, Paige MF. Fluorescence anisotropy imaging of a polydiacetylene photopolymer film. CAN J CHEM 2019. [DOI: 10.1139/cjc-2018-0360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
UV-illumination of phase-separated surfactant films prepared from mixtures of photopolymerizable 10,12-pentacosadiynoic acid and perfluorotetradecanoic acid results in the formation of fluorescent polydiacetylene fibers and aggregates. In this work, the orientation of polymer strands that comprise the resulting photopolymer structures has been probed using fluorescence anisotropy imaging in combination with defocused single-molecule fluorescence imaging. Imaging experiments indicate the presence of significant fiber-to-fiber heterogeneity, as well as anisotropy within each fiber (or aggregate), with both of these properties changing as a function of film preparation conditions. This anisotropy can be attributed to various alignments of the constituent polymer strands that comprise the larger fibers and aggregates. Intriguingly, when using defocused imaging, fiber images consisted of a series of discrete “doughnut” fluorescence emission patterns, which exhibited intermittent on–off blinking behavior; both of these properties are characteristic of individual emission transition dipoles (single molecules). Further, all of the individual emission transition dipoles had a uniform orientation with respect to the axis of the fiber, indicating a common orientation of discrete emitters in the larger polymer fiber. The implications of these results for future studies of the electronic properties of conjugated polymers in larger macroscopic systems are noted.
Collapse
|
30
|
Gao C, Seow JY, Zhang B, Hall CR, Tilley AJ, White JM, Smith TA, Wong WWH. Tetraphenylethene 9,10-Diphenylanthracene Derivatives - Synthesis and Photophysical Properties. Chempluschem 2019; 84:746-753. [PMID: 31944010 DOI: 10.1002/cplu.201900100] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 03/27/2019] [Indexed: 12/20/2022]
Abstract
A series of tetraphenylethene 9,10-diphenylanthracene (TPE-DPA) derivatives have been synthesized, and their photophysical properties studied. Photoluminescence measurements in PMMA, neat films and nanoparticle dispersions reveal that different aggregation states are formed, which leads to different photophysical behavior. The triplet excited state properties were studied using Pt(II) octaethylporphyrin (PtOEP) as triplet sensitizer. Upconverted emission from the DPA moiety is observed in nanoparticle dispersions of each derivative. A higher upconverted emission intensity is observed in aerated (compared to deaerated) solutions of the derivatives following irradiation, which is attributed to oxidation of the TPE moiety. These results provide valuable insight for the design of AIE luminogens for triplet-triplet annihilation upconversion (TTA-UC).
Collapse
|
31
|
Bo YF, Liu YY, Soleimaninejad H, Yu MN, Xie LH, Smith TA, Ghiggino KP, Huang W. Photophysical Identification of Three Kinds of Low-Energy Green Band Defects in Wide-Bandgap Polyfluorenes. J Phys Chem A 2019; 123:2789-2795. [DOI: 10.1021/acs.jpca.9b00188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
32
|
Mao W, Hall CR, Chesman ASR, Forsyth C, Cheng Y, Duffy NW, Smith TA, Bach U. Cover Picture: Visualizing Phase Segregation in Mixed‐Halide Perovskite Single Crystals (Angew. Chem. Int. Ed. 9/2019). Angew Chem Int Ed Engl 2019. [DOI: 10.1002/anie.201900853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
33
|
Mao W, Hall CR, Chesman ASR, Forsyth C, Cheng Y, Duffy NW, Smith TA, Bach U. Titelbild: Visualisierung der Phasensegregation in Gemischthalogenid‐ Perowskiteinkristallen (Angew. Chem. 9/2019). Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
34
|
Mao W, Hall CR, Chesman ASR, Forsyth C, Cheng YB, Duffy NW, Smith TA, Bach U. Visualizing Phase Segregation in Mixed-Halide Perovskite Single Crystals. Angew Chem Int Ed Engl 2019; 58:2893-2898. [PMID: 30456831 DOI: 10.1002/anie.201810193] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/13/2018] [Indexed: 11/08/2022]
Abstract
Mixed organolead halide perovskites (MOHPs), CH3 NH3 Pb(Brx I1-x )3 , have been shown to undergo phase segregation into iodide-rich domains under illumination, which presents a major challenge to their development for photovoltaic and light-emitting devices. Recent work suggested that phase-segregated domains are localized at crystal boundaries, driving investigations into the role of edge structure and the growth of larger crystals with reduced surface area. Herein, a method for growing large (30×30×1 μm3 ) monocrystalline MAPb(Brx I1-x )3 single crystals is presented. The direct visualization of the growth of nanocluster-like I-rich domains throughout the entire crystal revealed that grain boundaries are not required for this transformation. Narrowband fluorescence imaging and time-resolved spectroscopy provided new insight into the nature of the phase-segregated domains and the collective impact on the optoelectronic properties.
Collapse
|
35
|
Flint KL, Collins JG, Bradley SJ, Smith TA, Sumby CJ, Keene FR. Synthesis and Characterisation of Helicate and Mesocate Forms of a Double-Stranded Diruthenium(II) Complex of a Di(terpyridine) Ligand. Aust J Chem 2019. [DOI: 10.1071/ch19220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A diruthenium(ii) complex involving the di(terpyridine) ligand 1,2-bis{5-(5″-methyl-2,2′:6′,2″-terpyridinyl)}ethane was synthesised by heating an equimolar ratio of RuCl3 and the ligand under reflux conditions in ethylene glycol for 3 days, realising double-stranded helicate and mesocate forms which were chromatographically separated. The two species were obtained in relatively low yield (each ~7–9%) from the reaction mixture. X-Ray structural studies revealed differences in the cavity sizes of the two structures, with the helicate structure having a significantly smaller cavity. Furthermore, the helicate and mesocate forms pack with notably different arrangements of the structures with the helicate having large solvent and anion filled pores. 1D/2D NMR studies revealed rigidity in the mesocate structure relative to that of the helicate, such that the –CH2CH2– signal was split in the former and appeared as a singlet in the latter. In a manner analogous to the behaviour of the parent [Ru(tpy)2]2+ coordination moiety (tpy=2,2′:6′,2″-terpyridine), photophysical studies indicated that both the helicate and mesocate forms were non-emissive at ~610nm at room temperature, but at 77K in n-butyronitrile, both isomers showed emission at ~610nm (λex 472nm). However, the temporal emission characteristics were very different: time-resolved studies showed the emission of the helicate species decayed with a dominant emission lifetime of ~10 μs (similar to the emissive properties of free [Ru(tpy)2]2+ under the same conditions), whereas for the mesocate the emission lifetime was at least three orders of magnitude lower (~4 ns).
Collapse
|
36
|
Lin J, Liu B, Yu M, Wang X, Lin Z, Zhang X, Sun C, Cabanillas-Gonzalez J, Xie L, Liu F, Ou C, Bai L, Han Y, Xu M, Zhu W, Smith TA, Stavrinou PN, Bradley DDC, Huang W. Ultrastable Supramolecular Self-Encapsulated Wide-Bandgap Conjugated Polymers for Large-Area and Flexible Electroluminescent Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1804811. [PMID: 30370608 DOI: 10.1002/adma.201804811] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/17/2018] [Indexed: 06/08/2023]
Abstract
Controlling chain behavior through smart molecular design provides the potential to develop ultrastable and efficient deep-blue light-emitting conjugated polymers (LCPs). Herein, a novel supramolecular self-encapsulation strategy is proposed to construct a robust ultrastable conjugated polydiarylfluorene (PHDPF-Cz) via precisely preventing excitons from interchain cross-transfer/coupling and contamination from external trace H2 O/O2 . PHDPF-Cz consists of a mainchain backbone where the diphenyl groups localize at the 9-position as steric bulk moieties, and carbazole (Cz) units localize at the 4-position as supramolecular π-stacked synthon with the dual functionalities of self-assembly capability and hole-transport facility. The synergistic effect of the steric bulk groups and π-stacked carbazoles affords PHDPF-Cz as an ultrastable property, including spectral, morphological stability, and storage stability. In addition, PHDPF-Cz spin-coated gelation films also show thickness-insensitive deep-blue emission with respect to the reference polymers, which are suitable to construct solution-processed large-scale optoelectronic devices with higher reproducibility. High-quality and uniform deep-blue emission is observed in large-area solution-processed films. The electroluminescence shows high-quality deep-blue intrachain emission with a CIE (0.16, 0.12) and a very narrow full width at half-maximum of 32 nm. Finally, large-area and flexible polymer light-emitting devices with a single-molecular excitonic behavior are also fabricated. The supramolecular self-encapsulation design provides an effective strategy to construct ultrastable LCPs for optoelectronic applications.
Collapse
|
37
|
Enders F, Budweg A, Zeng P, Lauth J, Smith TA, Brida D, Boldt K. Switchable dissociation of excitons bound at strained CdTe/CdS interfaces. NANOSCALE 2018; 10:22362-22373. [PMID: 30474672 DOI: 10.1039/c8nr07973k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Charge carrier dynamics of semiconductor nano-heterostructures are determined by band alignment and lattice mismatch of the adjacent materials. However, quantum efficiencies for the separation of excited charge carriers at such an interface are hard to predict and cannot yet be easily controlled. In this work we examine nanorods with a severely strained, axial CdTe/CdS interface using femtosecond transient absorption spectroscopy. We show that charge separation is mitigated by equal contributions of valence band distortion and formation of coulomb pairs across the interface. Left undisturbed such localised excitons relax rapidly via non-radiative recombination channels. By adding a competitive hole acceptor that disrupts the coulomb interaction we overcome the synergetic co-localisation of the carriers and realise charge separation. The thus created long-lived state can be exploited for a broad range of applications such as photocatalysis, water splitting, and switchable nanodevices.
Collapse
|
38
|
Stevens AL, Novakovic S, White JM, Wong WWH, Smith TA, Ghiggino KP, Paige MF, Steer RP. Exciton Dynamics of Photoexcited Pendant Porphyrin Polymers in Solution and in Thin Films. J Phys Chem A 2018; 122:9605-9614. [DOI: 10.1021/acs.jpca.8b09321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
39
|
Yu MN, Soleimaninejad H, Lin JY, Zuo ZY, Liu B, Bo YF, Bai LB, Han YM, Smith TA, Xu M, Wu XP, Dunstan DE, Xia RD, Xie LH, Bradley DDC, Huang W. Photophysical and Fluorescence Anisotropic Behavior of Polyfluorene β-Conformation Films. J Phys Chem Lett 2018; 9:364-372. [PMID: 29298074 DOI: 10.1021/acs.jpclett.7b03148] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We demonstrate a systematic visualization of the unique photophysical and fluorescence anisotropic properties of polyfluorene coplanar conformation (β-conformation) using time-resolved scanning confocal fluorescence imaging (FLIM) and fluorescence anisotropy imaging microscopy (FAIM) measurements. We observe inhomogeneous morphologies and fluorescence decay profiles at various micrometer-sized regions within all types of polyfluorene β-conformational spin-coated films. Poly(9,9-dioctylfluorene-2,7-diyl) (PFO) and poly[4-(octyloxy)-9,9-diphenylfluoren-2,7-diyl]-co-[5-(octyloxy)-9,9-diphenylfluoren-2,7-diyl] (PODPF) β-domains both have shorter lifetime than those of the glassy conformation for the longer effective conjugated length and rigid chain structures. Besides, β-conformational regions have larger fluorescence anisotropy for the low molecular rotational motion and high chain orientation, while the low anisotropy in glassy conformational regions shows more rotational freedom of the chain and efficient energy migration from amorphous regions to β-conformation as a whole. Finally, ultrastable ASE threshold in the PODPF β-conformational films also confirms its potential application in organic lasers. In this regard, FLIM and FAIM measurements provide an effective platform to explore the fundamental photophysical process of conformational transitions in conjugated polymer.
Collapse
|
40
|
Wang Y, Yao H, Zhou J, Hong Y, Chen B, Zhang B, Smith TA, Wong WWH, Zhao Z. A water-soluble, AIE-active polyelectrolyte for conventional and fluorescence lifetime imaging of mouse neuroblastoma neuro-2A cells. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/pola.28943] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
41
|
Liu M, Onchaiya S, Tan LYF, Haghighatbin MA, Luu T, Owyong TC, Hushiarian R, Hogan CF, Smith TA, Hong Y. 9-Vinylanthracene Based Fluorogens: Synthesis, Structure-Property Relationships and Applications. Molecules 2017; 22:molecules22122148. [PMID: 29207549 PMCID: PMC6149741 DOI: 10.3390/molecules22122148] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/24/2017] [Accepted: 12/01/2017] [Indexed: 01/16/2023] Open
Abstract
Fluorescent dyes with aggregation-induced emission (AIE) properties exhibit intensified emission upon aggregation. They are promising candidates to study biomolecules and cellular changes in aqueous environments when aggregation formation occurs. Here, we report a group of 9-position functionalized anthracene derivatives that were conveniently synthesized by the palladium-catalyzed Heck reaction. Using fluorometric analyses, these dyes were confirmed to show AIE behavior upon forming aggregates at high concentrations, in viscous solvents, and when poorly solubilized. Their photophysical properties were then further correlated with their structural features, using density functional theory (DFT) calculation. Finally, we demonstrated their potential applications in monitoring pH changes, quantifying globular proteins, as well as cell imaging with confocal microscopy.
Collapse
|
42
|
Smith DA, McKenzie G, Jones AC, Smith TA. Analysis of time-correlated single photon counting data: a comparative evaluation of deterministic and probabilistic approaches. Methods Appl Fluoresc 2017; 5:042001. [PMID: 29063861 DOI: 10.1088/2050-6120/aa8055] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We review various methods for analysing time-resolved fluorescence data acquired using the time-correlated single photon counting method in an attempt to evaluate their benefits and limitations. We have applied these methods to both experimental and simulated data. The relative merits of using deterministic approaches, such as the commonly used iterative reconvolution method, and probabilistic approaches, such as the smoothed exponential series method, the maximum entropy method and recently proposed basis pursuit denoising (compressed sensing) method, are outlined. In particular, we show the value of using multiple methods to arrive at the most appropriate choice of model. We show that the use of probabilistic analysis methods can indicate whether a discrete component or distribution analysis provides the better representation of the data.
Collapse
|
43
|
Ritchie C, Vamvounis G, Soleimaninejad H, Smith TA, Bieske EJ, Dryza V. Photochrome-doped organic films for photonic keypad locks and multi-state fluorescence. Phys Chem Chem Phys 2017; 19:19984-19991. [PMID: 28722049 DOI: 10.1039/c7cp02818k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The spectroscopic properties of poly(methyl methacrylate) polymer films doped with two kinds of photochromic molecular switches are investigated. A green-fluorescent sulfonyl diarylethene (P1) is combined with either a non-fluorescent diarylethene (P2) or red-fluorescent spiropyran (P3). Photoswitching between the colorless and colored isomers (P1: o-BTFO4 ↔ c-BTFO4, P2: o-DTE ↔ c-DTE, P3: SP ↔ MC) enables the P1 + P2 and P1 + P3 films to be cycled through three distinct states. From the initial state (o-BTFO4 + o-DTE/SP), irradiation with UV light generates the second state (c-BTFO4 + c-DTE/MC), where c-BTFO4 → c-DTE/MC energy transfer is established. Irradiation with green light then generates the third state (c-BTFO4 + o-DTE/SP), where the energy transfer acceptor is no longer present. Finally, irradiation with blue light regenerates the initial state. For the P1 + P2 film, only one state is fluorescent, with the irradiation inputs required to be entered in the correct order to access this state, acting as a keypad lock. For the P1 + P3 film, the states emit either no fluorescence, red fluorescence, or green fluorescence, all using a common excitation wavelength. Additionally, once the fluorescence is activated with UV light, it undergoes a time-dependent color transition from red to green, due to the pairing of P-type and T-type photochromes. These multi-photochromic systems may be useful for security ink or imaging applications.
Collapse
|
44
|
Breukers RD, Smith GJ, Stirrat HL, Swanson AJ, Smith TA, Ghiggino KP, Raymond SG, Winch NM, Clarke DJ, Kay AJ. Light losses from scattering in luminescent solar concentrator waveguides. APPLIED OPTICS 2017; 56:2630-2635. [PMID: 28375222 DOI: 10.1364/ao.56.002630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The reductions in the transmission of emission originating from a fluorophore dissolved in a polymer matrix due to light scattering were compared in two forms of planar waveguides used as luminescent solar concentrators: a thin film of poly(methylmethacrylate) (PMMA) spin-coated on a glass plate and a solid PMMA plate of the same dimensions. The losses attributable to light scattering encountered in the waveguide consisting of the thin film of polymer coated on a glass plate were not detectable within experimental uncertainty, whereas the losses in the solid polymer plate were significant. The losses in the solid plate are interpreted as arising from light-scattering centers comprising minute bubbles of vapor/gas, incomplete polymerization or water clusters that are introduced during or after the thermally induced polymerization process.
Collapse
|
45
|
Geraghty PB, Lee C, Subbiah J, Wong WWH, Banal JL, Jameel MA, Smith TA, Jones DJ. High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension. Beilstein J Org Chem 2017; 12:2298-2314. [PMID: 28144297 PMCID: PMC5238583 DOI: 10.3762/bjoc.12.223] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 10/12/2016] [Indexed: 12/04/2022] Open
Abstract
The synthesis of key 4-alkyl-substituted 5-(trimethylsilyl)thiophene-2-boronic acid pinacol esters 3 allowed a simplified alkylthiophene catenation process to access bis-, ter-, quater-, and quinquethiophene π-bridges for the synthesis of acceptor–π-bridge-donor– π-bridge-acceptor (A–π-D–π-A) electron donor molecules. Based on the known benzodithiophene-terthiophene-rhodanine (BTR) material, the BXR series of materials, BMR (X = M, monothiophene), BBR (X = B, bithiophene), known BTR (X = T, terthiophene), BQR (X = Q, quaterthiophene), and BPR (X = P(penta), quinquethiophene) were synthesised to examine the influence of chromophore extension on the device performance and stability for OPV applications. The BTxR (x = 4, butyl, and x = 8, octyl) series of materials were synthesised by varying the oligothiophene π-bridge alkyl substituent to examine structure–property relationships in OPV device performance. The devices assembled using electron donors with an extended chromophore (BQR and BPR) are shown to be more thermally stable than the BTR containing devices, with un-optimized efficiencies up to 9.0% PCE. BQR has been incorporated as a secondary donor in ternary blend devices with PTB7-Th resulting in high-performance OPV devices with up to 10.7% PCE.
Collapse
|
46
|
Soleimaninejad H, Chen MZ, Lou X, Smith TA, Hong Y. Measuring macromolecular crowding in cells through fluorescence anisotropy imaging with an AIE fluorogen. Chem Commun (Camb) 2017; 53:2874-2877. [DOI: 10.1039/c6cc09916e] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We report a new strategy that allows spatiotemporal visualization of the macromolecular crowding effect in cells.
Collapse
|
47
|
Gao M, Hong Y, Chen B, Wang Y, Zhou W, Wong WWH, Zhou J, Smith TA, Zhao Z. AIE conjugated polyelectrolytes based on tetraphenylethene for efficient fluorescence imaging and lifetime imaging of living cells. Polym Chem 2017. [DOI: 10.1039/c7py00564d] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
New conjugated polyelectrolytes based on tetraphenylethene are prepared, which show good performance in fluorescence imaging and fluorescence lifetime imaging of living cells.
Collapse
|
48
|
Rapson AC, Gee ML, Clayton AHA, Smith TA. Interactions of a lytic peptide with supported lipid bilayers investigated by time-resolved evanescent wave-induced fluorescence spectroscopy. Methods Appl Fluoresc 2016; 4:044001. [DOI: 10.1088/2050-6120/4/4/044001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
49
|
Winch NM, Smith GJ, Breukers RD, Bhuiyan DH, Kay AJ, Smith TA, Ghiggino KP, Raymond SG. The photophysics of phenylenevinylene oligomers and self-absorption of their fluorescence in polymer films. Photochem Photobiol Sci 2016; 15:1163-1169. [PMID: 27480331 DOI: 10.1039/c6pp00127k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fluorescence spectra, quantum yields and lifetimes of a series of alkoxy-substituted phenylenevinylene molecules, which serve as short chain oligomer models for poly(p-phenylenevinylene), have been determined in fluid solvents and in a high viscosity polymer matrix. The effects of solvent polarity and a high viscosity molecular environment on the fluorescence yields and spectral shapes have been established. Alkoxy group substitution on the phenyl ring moieties of the molecules has an important effect on the vibronic structures and profiles of the absorption spectra. This was interpreted in terms of hot-band, ground to excited singlet state transitions from energetically closely-spaced torsional vibrational levels of the vinylene double bond in the ground state. The shapes of the absorption bands affect the overlaps of the absorption and fluorescence spectra. This has been quantified as the probability of fluorescence reabsorption in solid polymer films as a function of pathlength. This is an important determinant of the efficacies of these compounds for "harvesting" solar energy in luminescent solar concentrator systems. The reabsorption probabilities of these compounds are lower for all pathlengths than those determined in the same polymer film for the fluorophores, perylene and perylene diimide, which have been considered for concentrating spatially diffuse sunlight.
Collapse
|
50
|
Zeng P, Kirkwood N, Mulvaney P, Boldt K, Smith TA. Shell effects on hole-coupled electron transfer dynamics from CdSe/CdS quantum dots to methyl viologen. NANOSCALE 2016; 8:10380-10387. [PMID: 27139145 DOI: 10.1039/c6nr00168h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electron transfer (ET) dynamics from the 1Se electron state in quasi-type II CdSe/CdS core/shell quantum dots (QDs) to adsorbed methyl viologen (MV(2+)) were measured using femtosecond transient absorption spectroscopy. The intrinsic ET rate kET was determined from the measured average number of ET-active MV(2+) per QD, which permits reliable comparisons of variant shell thickness and different hole states. The 1Se electron was extracted efficiently from the CdSe core, even for CdS shells up to 20 Å thick. The ET rate decayed exponentially from 10(10) to 10(9) s(-1) for increasing CdS shell thicknesses with an attenuation factor β≈ 0.13 Å(-1). We observed that compared to the ground state exciton 1Se1S3/2 the electron coupled to the 2S3/2 hot hole state exhibited slower ET rates for thin CdS shells. We attribute this behaviour to an Auger-assisted ET process (AAET), which depends on electron-hole coupling controlled by the CdS shell thickness.
Collapse
|