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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 325: 125176, 2024 Sep 20.
Article in English | MEDLINE | ID: mdl-39316860

ABSTRACT

This study explored the enhancement of near-infrared emissions in YbVO4: Er3+ through Y3+ ion doping under a 980 nm laser excitation. The phosphor exhibits weak green emissions at 527 nm (2H11/2 â†’ 4I15/2) and 553 nm (4S3/2 â†’ 4I15/2), red emissions at 654 nm (4F9/2 â†’ 4I15/2), and a strong near-infrared emission at 803 nm (4I9/2 â†’ 4I15/2). Optimal doping concentration of Y3+ ion in YbVO4: 0.02 Er3+ was determined to be 0.1, resulting in a 7.6-fold enhancement of near-infrared luminescence. This enhancement is attributed to defect bands facilitating energy transfer from green and red levels to the near-infrared levels. Furthermore, a multi-mode temperature sensor based on YbVO4: Er3+/Y3+ was developed, offering four distinct temperature sensing modes: TCEL of 2H11/2/4S3/2, NTCEL of 2H11/2/4F9/2 and 4S3/2/4F9/2, and single luminescence emission intensity of 4I9/2 energy level. The sensor demonstrates maximum relative sensitivities of 1.17 % K-1 at 298 K, 0.66 % K-1 at 298 K, 0.41 % K-1 at 298 K and 1.29 % K-1 at 673 K. YbVO4: Er3+/Y3+ phosphor exhibits high temperature sensitivity, showcasing significant potential for optical temperature sensing applications.

2.
Angew Chem Int Ed Engl ; : e202415815, 2024 Sep 24.
Article in English | MEDLINE | ID: mdl-39316428

ABSTRACT

Thermochromic fluorescent materials (TFMs) have attracted significant attention due to their unique fluorescent colorimetric response to temperature. However, existing TFMs still suffer from weak stimulus responsiveness, broad temperature response ranges, uncontrollable emission color changes, and low quantum yields. In this study, we address these issues by designing and synthesizing three diketone-boron complexes with distinct emission wavelengths (NWPU-(2-4)). Utilizing a molecular engineering strategy to manipulate intramolecular charge transfer transitions and molecular packing modes, our synthesized complexes exhibit efficient fluorescence emission in both solution and solid states. Moreover, their emission wavelengths are highly sensitive to environmental polarity. By incorporating these compounds into thermosensitive matrices of long-chain alkanes, we produced TFMs with varied fluorescence emission peak variation ranges. Notably, the TFM based on NWPU-4, owing to its strong charge transfer transitions and dense J-aggregate packing configuration, not only exhibits intense fluorescence emission spanning the deep red to near-infrared spectrum but also displays a remarkable 90 nm broad range of thermochromic properties. Ultimately, it was successfully applied to programmable, thermally controlled, multi-level information encryption.

3.
Angew Chem Int Ed Engl ; : e202412483, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-39218804

ABSTRACT

Purely organic molecules exhibiting near-infrared (NIR) emission possess considerable potential for applications in both biological and optoelectronic technological domains, owing to their inherent advantages such as cost-effectiveness, biocompatibility, and facile chemical modifiability. However, the repertoire of such molecules with emission peaks exceeding 750 nm and concurrently demonstrating high photoluminescence quantum efficiency (PLQE) remains relatively scarce due to the energy gap law. Herein, we report two open-shell NIR radical emitters, denoted as DMNA-Cz-BTM and DMNA-PyID-BTM, achieved through the strategic integration of a donor group (DMNA) onto the Cz-BTM and PyID-BTM frameworks, respectively. We found that the donor-acceptor molecular structure allows the two designed radical emitters to exhibit a charge-transfer excited state and spatially separated electron and hole levels with non-bonding characteristics. Thus, the high-frequency vibrations are effectively suppressed. Besides, the reduction of low-frequency vibrations is observed. Collectively, the non-radiative decay channel is significantly suppressed, leading to exceptional NIR PLQE values. Specifically, DMNA-Cz-BTM manifests an emission peak at 758 nm alongside a PLQE of 55%, whereas DMNA-PyID-BTM exhibits an emission peak at 778 nm with a PLQE of 66%. Notably, these represent the pinnacle of PLQE among metal-free organic NIR emitters with emission peaks surpassing 750 nm.

4.
Talanta ; 281: 126865, 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39265422

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD) poses a significant global health concern, necessitating precise diagnostic tools and effective treatment strategies. Peroxynitrite (ONOO-), a reactive oxygen species, plays a pivotal role in NAFLD pathogenesis, highlighting its potential as a biomarker for disease diagnosis and therapeutic evaluation. This study reports on the development of a near-infrared (NIR) fluorescent probe, designated DRP-O, for the selective detection of ONOO- with high sensitivity and photostability. DRP-O exhibits rapid response kinetics (within 2 min) and an impressive detection limit of 2.3 nM, enabling real-time monitoring of ONOO- dynamics in living cells. Notably, DRP-O demonstrates excellent photostability under continuous laser irradiation, ensuring reliable long-term monitoring in complex biological systems. We apply DRP-O to visualize endogenous ONOO- in living cells, demonstrating its potential for diagnosing and monitoring NAFLD-related oxidative stress. Furthermore, DRP-O effectively evaluates the efficacy of therapeutic drugs in NAFLD cell models, underscoring its potential utility in drug screening studies. Moreover, we confirm DRP-O to enable selective identification of fatty liver tissues in a mouse model of NAFLD, indicating its potential for the early diagnosis of NAFLD. Collectively, DRP-O represents a valuable tool for studying ONOO- dynamics, evaluating drug efficacy, and diagnosing NAFLD, offering insights into novel therapeutic strategies for this prevalent liver disorder.

5.
Adv Healthc Mater ; : e2401513, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-39091058

ABSTRACT

Carbon dots (CDs) with good optical properties, biocompatibility, easy functionalization, and small size have attracted more and more attention and laid a good foundation for their applications in the biomedicine field. CDs emitted in near-infrared regions (NIR-CDs) can achieve high penetration depth imaging and produce high cytotoxic substance for disease treatment. Therefore, NIR-CDs are promising materials to realize high-quality imaging-guided diagnostic and therapeutic integration. This review first introduces the current mainstream synthesis methods of NIR-CDs by "top-down" and "bottom-up". Second, the luminescence modes of NIR-CDs are introduced, and the luminescence mechanisms based on carbon core state, surface state, molecular state, and crosslinking enhanced emission are summarized. Third, the applications and principles of NIR-CDs in imaging, drug delivery, and non-invasive therapeutics are introduced from a view of diagnosis and therapy. Finally, their prospects and challenges in biomedical and biotechnological applications are outlined.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 323: 124924, 2024 Dec 15.
Article in English | MEDLINE | ID: mdl-39111029

ABSTRACT

In this work, the network structure of Er3+ doped tellurite glass was modified by incorporating MoO3/WO3 oxides and the effect of the structural modification on the near-infrared luminescence properties of Er3+ was investigated. The examination of fluorescence spectrum reveals that partial substituting TeO2 with MoO3/WO3 in the composition significantly enhances both the emission intensity and the FWHM (full width at half maximum) of the 1.53 µm band, and the improved local environment around Er3+ ions and phonon energy of glass host are considered to be responsible for these results. The XRD pattern, Raman spectrum and Judd-Ofelt intensity parameter disclosed the changes in network structure and phonon energy, the DSC curve showed an improvement in thermal stability, and fluorescence decay curve displayed the increase of Er3+ lifetime at the 4I13/2 level, all of these indicated the positive effect of MoO3/WO3 addition on the near-infrared luminescence properties of Er3+.

7.
Adv Sci (Weinh) ; 11(35): e2403398, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39023182

ABSTRACT

This study describes the formation of single-chain polymer dots (Pdots) via ultrasonic emulsification of nonionic donor-acceptor-donor type (D-A-D) alkoxy thiophene-benzobisthiadiazole-based conjugated polymers (Poly BT) with amphiphilic cetyltrimethylammonium bromide (CTAB). The methodology yields Pdots with a high cationic surface charge (+56.5 mV ± 9.5) and average hydrodynamic radius of 12 nm. Optical characterization reveals that these Pdots emit near-infrared (NIR) light at a maximum wavelength of 860 nm owing to their conjugated polymer backbone consisting of D-A-D monomers. Both colloidal and optical properties of these Pdots make them promising fluorescence emissive probes for bioimaging applications. The significant advantage of positively charged Pdots is demonstrated in diffusion-limited mediums such as tissues, utilizing human epithelial breast adenocarcinoma, ATCC HTB-22 (MCF-7), human bone marrow neuroblastoma, ATCC CRL-2266 (SH-SY5Y), and rat adrenal gland pheochromocytoma, CRL-1721 (PC-12) tumor spheroid models. Fluorescence microscopy analysis of tumor spheroids from MCF-7, SH-SY5Y, and PC-12 cell lines reveals the intensity profile of Pdots, confirming extensive penetration into the central regions of the models. Moreover, a comparison with mitochondria staining dye reveals an overlap between the regions stained by Pdots and the dye in all three tumor spheroid models. These results suggest that single-chain D-A-D type Pdots, cationized via CTAB, exhibit long-range mean free path of penetration (≈1 µm) in dense mediums and tumors.


Subject(s)
Polymers , Spheroids, Cellular , Humans , Polymers/chemistry , Animals , Cell Line, Tumor , Rats , Quantum Dots/chemistry , MCF-7 Cells , Imaging, Three-Dimensional/methods
8.
Adv Mater ; : e2407875, 2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39049679

ABSTRACT

Unlike traditional photoluminescence (PL), mechanoluminescence (ML) achieved under mechanical excitation demonstrates unique characteristics such as high penetrability, spatial resolution, and signal-to-background ratio (SBR) for bioimaging applications. However, bioimaging with organic mechanoluminescent materials remains challenging because of the shallow penetration depth of ML with short emission wavelengths and the absence of a suitable mechanical force to generate ML in vivo. To resolve these issues, the present paper reports the achievement of ultrasound (US)-excited fluorescence and phosphorescence from purely organic luminogens for the first time with emission wavelengths extending to the red/NIR region, with the penetrability of the US-excited emission being considerably higher than that of PL. Consequently, US-excited subcutaneous phosphorescence imaging can be achieved using a mechanoluminescent-luminogen-based capsule device with a quantified intensity of 9.15 ± 1.32 × 104 p s-1 cm-2 sr-1 and an SBR of 24. Moreover, the US-excited emission can be adequately tuned using the packing modes of the conjugated skeletons, dipole orientation of mechanoluminescent luminogens, and strength and direction of intermolecular interactions. Overall, this study innovatively expands the kind of excitation sources and the emission wavelengths of organic mechanoluminescent materials, paving the way for practical biological applications based on US-excited emission.

9.
Small ; : e2404426, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-39058212

ABSTRACT

Solution-processed colloidal III-V semiconductor-based quantum dots (QDs) represent promising and environmentally-friendly alternatives to Cd-based QDs in the realms of optoelectronics and biological applications. While InP-based core-shell QDs have demonstrated efficient light-emitting diode (LED) performance in the visible region, achieving deep-red emission (above 700 nm) with a narrow linewidth has proven challenging. Herein, the study presents a novel strategy for synthesizing InP/ZnSe/ZnS core-shell-shell QDs tailored for emission in the first biological transparency window. The resulting QDs exhibit an emission wavelength up to 725 nm with a narrow peak full width at half maximum (FWHM) down to 107 meV (45 nm). To enhance the biocompatibility and chemical stability of the QDs, their surface is further capped with a layer of amorphous alumina resulting in an InP/ZnSe/ZnS/Al2O3 heterostructure. This surface passivation not only ensures environmental- and photostability but also enhances the photoluminescence quantum yield (PLQY). The alumina capping enables the aqueous phase transfer via surface ligand exchange using mercaptopropionic acid (MPA) while maintaining the initial quantum yield. The resulting QDs demonstrate a significant potential for advancing next-generation optoelectronic technologies and bio-applications.

10.
Molecules ; 29(11)2024 May 24.
Article in English | MEDLINE | ID: mdl-38893352

ABSTRACT

Molecular probes with the ability to differentiate between subcellular variations in acidity levels remain important for the investigation of dynamic cellular processes and functions. In this context, a series of cyclic peptide and PEG bio-conjugated dual near-infrared emissive BF2-azadipyrromethene fluorophores with maxima emissions at 720 nm (at pH > 6) and 790 nm (at pH < 5) have been developed and their aqueous solution photophysical properties determined. Their inter-converting emissions and fluorescence lifetime characteristics were exploited to track their spatial and temporal progression from first contact with the plasma membrane to subcellular locales to their release within extracellular vesicles. A pH-dependent reversible phenolate/phenol interconversion on the fluorophore controlled the dynamic changes in dual emission responses and corresponding lifetime changes. Live-cell confocal microscopy experiments in the metastatic breast cancer cell line MDA-MB-231 confirmed the usability of the dual emissive properties for imaging over prolonged periods. All three derivatives performed as probes capable of real-time continuous imaging of fundamental cellular processes such as plasma membrane interaction, tracking endocytosis, lysosomal/large acidic vesicle accumulation, and efflux within extracellular vesicles without perturbing cellular function. Furthermore, fluorescence lifetime imaging microscopy provided valuable insights regarding fluorophore progression through intracellular microenvironments over time. Overall, the unique photophysical properties of these fluorophores show excellent potential for their use as information-rich probes.


Subject(s)
Cell Membrane , Fluorescent Dyes , Humans , Fluorescent Dyes/chemistry , Cell Membrane/metabolism , Cell Membrane/chemistry , Cell Line, Tumor , Microscopy, Confocal , Hydrogen-Ion Concentration , Microscopy, Fluorescence/methods , Endocytosis , Peptides, Cyclic/chemistry
11.
J Hazard Mater ; 475: 134914, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38885588

ABSTRACT

Due to the highly toxic nature of mercury ions to living organisms, accurately detecting Hg2+ in water samples and biological systems is of great significance. In this study, we designed and synthesized a novel red-to-near-infrared Aggregation-Induced Emission (AIE) fluorescent probe (named as DS) based Fluorene derivatives on specifically for Hg2+ detection. Probe DS can visually identify Hg2+ through an red-to-near-infrared fluorescence enhancement change, characterized by a large Stokes shift (130 nm) and AIE feature. This probe offers a fast response, high selectivity and sensitivity. The Hg2+-induced deprotection reaction of the thioketal mechanism was thoroughly investigated using nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS) and density functional theory (DFT) calculation. Additionly, dynamic light scattering (DLS) results indicated that the aggregation states changes of the molecular play a crucial role in the AIE fluorescence response of probe DS toward Hg2+. The red-to-near-infrared response with AIE feature not only avoids the interference of auto-fluorescence signals in complex environments, but also reduces the fluorescence quenching caused by probe molecular aggregation. This makes probe DS highly suitable for high-quality imaging detection of Hg2+ in aqueous environments. Furthermore, probe DS demonstrates the capability for visual fluorescence detection of Hg2+ concentrations in water sample, plant roots and living cells.


Subject(s)
Fluorescent Dyes , Mercury , Mercury/analysis , Mercury/chemistry , Fluorescent Dyes/chemistry , Humans , Spectrometry, Fluorescence , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry , Fluorenes/chemistry , Fluorenes/toxicity , HeLa Cells
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 320: 124647, 2024 Nov 05.
Article in English | MEDLINE | ID: mdl-38880075

ABSTRACT

Inflammation is a complex physiological response involving various cellular and molecular events. Sulfur dioxide (SO2), recognized as both an endogenous signaling molecule and anti-inflammatory agent, plays a crucial role in modulating inflammation and maintaining cellular homeostasis. To gain deeper insights into the dynamics of inflammation-related processes, real-time monitoring of SO2 concentrations within cellular organelles is imperative. Here, we developed a near-infrared fluorescent probe, R2, equipped with lysosomal targeting features. R2 effectively monitors dynamic SO2 concentration changes during inflammation. The fluorescence intensity at 703 nm of R2 shows a strong linear correlation with the concentration of SO2, displaying a rapid response time to SO2 within 10 s and maintaining excellent photostability. The successful application of R2 in elucidating dynamic SO2 concentration changes in lysosomal during cellular and rat inflammatory processes underscores its significant potential as a tool for understanding the pathogenesis of inflammation-related diseases.


Subject(s)
Fluorescent Dyes , Inflammation , Lysosomes , Sulfur Dioxide , Lysosomes/metabolism , Lysosomes/chemistry , Sulfur Dioxide/analysis , Animals , Inflammation/metabolism , Fluorescent Dyes/chemistry , Humans , Rats , Mice , Spectrometry, Fluorescence , Male
13.
Chemistry ; 30(39): e202400927, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38773816

ABSTRACT

Tris(2,4,6-trichlorophenyl)methyl (TTM) group has been widely used for constructing organic radicals, but the poor optical stabilities limit the application prospects of the TTM radicals. In this work, the rigid B- and N-embedded dioxygen-bridged (BO and NO) units were attached to the TTM skeleton as the strong electron-withdrawing and electron-donating groups, respectively. The rigidity and strong electronic effect of the BO and NO units contribute to the high chemical and optical stability of BO-TTM and NO-TTM radicals. Notably, NO-TTM exhibits near-infrared emission at 830 nm with a narrow full width at half maximum (FWHM) of 55 nm (100 meV), while BO-TTM shows blue-shifted luminescence at 635 nm and a narrower FWHM of merely 43 nm (130 meV). This study has developed a methodology to produce highly efficient and enduring luminescent radicals, which could tune emission properties such as wavelength and FWHM.

14.
Angew Chem Int Ed Engl ; 63(24): e202403827, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38589299

ABSTRACT

Organic radicals with narrow energy gaps are highly sought-after for the production of near-infrared (NIR) fluorophores. However, the current repertoire of developed organic radicals is notably limited, facing challenges related to stability and low fluorescence efficiency. This study addresses these limitations by achieving stable radicals in nonconjugated poly(diphenylmethane) (PDPM). Notably, PDPM exhibits a well-balanced structural flexibility and rigidity, resulting in a robust intra-/inter-chain through-space conjugation (TSC). The stable radicals within PDPM, coupled with strong TSC, yield a remarkable full-spectrum emission spanning from blue to NIR beyond 900 nm. This extensive tunability is achieved through careful adjustments of concentration and excitation wavelength. The findings highlight the efficacy of polymerization in stabilizing radicals and introduce a novel approach for developing nonconjugated NIR emitters based on triphenylmethane subunits.

15.
Acta Biomater ; 180: 394-406, 2024 05.
Article in English | MEDLINE | ID: mdl-38615810

ABSTRACT

The construction and optimization of a single phototherapeutic agent with photoluminescence, type I photodynamic therapy (PDT), and photothermal therapy (PTT) functions remain challenging. In this study, we aimed to design and synthesize four donor-acceptor (D-A) type aggregation-induced emission molecules: PSI, TPSI, PSSI, and TPSSI. We employed phenothiazine as an electron donor and 1,3-bis(dicyanomethylidene)indan as a strong electron acceptor in the synthesis process. Among them, TPSSI exhibited efficient type I reactive oxygen species generation, high photothermal conversion efficiency (45.44 %), and near-infrared emission. These observations can be attributed to the introduction of a triphenylamine electron donor group and a thiophene unit, which resulted in increased D-A strengths, a reduced singlet-triplet energy gap, and increased free intramolecular motion. TPSSI was loaded into bovine serum albumin to prepare biocompatible TPSSI nanoparticles (NPs). Our results have indicated that TPSSI NPs can target lipid droplets with negligible dark toxicity and can efficiently generate O2•- in hypoxic tumor environments. Moreover, TPSSI NPs selectively targeted 4T1 tumor tissues and exhibited a good PDT-PTT synergistic effect in vitro and in vivo. We believe that the successful preparation of multifunctional phototherapeutic agents will promote the development of efficient tumor diagnosis and treatment technologies. STATEMENT OF SIGNIFICANCE: The construction of a single phototherapeutic agent with photoluminescence, type I photodynamic therapy, and photothermal therapy functions, and its optimization remain challenging. In this study, we construct four donor-acceptor aggregation-induced emission molecules using phenothiazine as an electron donor and 1,3-Bis(dicyanomethylidene)indan as a strong electron acceptor. By optimizing the molecular structure, an integrated phototherapy agent with fluorescence imaging ability and high photodynamic / photothermal therapy performance was prepared. We believe that the successful preparation of multifunctional phototherapeutic agents will promote the development of efficient tumor diagnosis and treatment technology.


Subject(s)
Photochemotherapy , Photothermal Therapy , Animals , Photochemotherapy/methods , Mice , Female , Mice, Inbred BALB C , Cell Line, Tumor , Infrared Rays , Nanoparticles/chemistry , Nanoparticles/therapeutic use
16.
Materials (Basel) ; 17(7)2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38612222

ABSTRACT

In this study, we conducted an extensive investigation into broadband near-infrared luminescence of Cr3+-doped Ca3Y2Ge3O12 garnet, employing first-principles calculations within the density functional theory framework. Our initial focus involved determining the site occupancy of Cr3+ activator ions, which revealed a pronounced preference for the Y3+ sites over the Ca2+ and Ge4+ sites, as evidenced by the formation energy calculations. Subsequently, the geometric structures of the excited states 2E and 4T2, along with their optical transition energies relative to the ground state 4A2 in Ca3Y2Ge3O12:Cr3+, were successfully modeled using the ΔSCF method. Calculation convergence challenges were effectively addressed through the proposed fractional particle occupancy schemes. The constructed host-referred binding energy diagram provided a clear description of the luminescence kinetics process in the garnet, which explained the high quantum efficiency of emission. Furthermore, the accurate prediction of thermal excitation energy yielded insights into the thermal stability of the compound, as illustrated in the calculated configuration coordinate diagram. More importantly, all calculated data were consistently aligned with the experimental results. This research not only advances our understanding of the intricate interplay between geometric and electronic structures, optical properties, and thermal behavior in Cr3+-doped garnets but also lays the groundwork for future breakthroughs in the high-throughput design and optimization of luminescent performance and thermal stability in Cr3+-doped phosphors.

17.
Adv Mater ; 36(25): e2400347, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38573812

ABSTRACT

Suppressing trap-assisted nonradiative losses through passivators is a prerequisite for efficient perovskite light-emitting diodes (PeLEDs). However, the complex bonding between passivators and perovskites severely suppresses the passivation process, which still lacks comprehensive understanding. Herein, the number, category, and degree of bonds between different functional groups and the perovskite are quantitatively assessed to study the passivation dynamics. Functional groups with high electrostatic potential and large steric hindrance prioritize strong bonding with organic cations and halides on the perfect surface, leading to suppressed coordination with bulky defects. By modulating the binding priorities and coordination capacity, hindrance from the intense interaction with perfect perovskite is significantly reduced, leading to a more direct passivation process. Consequently, the near-infrared PeLED without external light out-coupling demonstrates a record external quantum efficiency of 24.3% at a current density of 42 mA cm-2. In addition, the device exhibits a record-level-cycle ON/OFF switching of 20 000 and ultralong half-lifetime of 1126.3 h under 5 mA cm-2. An in-depth understanding of the passivators can offer new insights into the development of high-performance PeLEDs.

18.
Adv Mater ; 36(28): e2402182, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38663035

ABSTRACT

Photosensitizers (PSs) with aggregation-induced emission (AIE) characteristics are competitive candidates for bioimaging and therapeutic applications. However, their short emission wavelength and nonspecific organelle targeting hinder their therapeutic effectiveness. Herein, a donor-acceptor modulation approach is reported to construct a series of ionic AIE photosensitizers with enhanced photodynamic therapy (PDT) outcomes and fluorescent emission in the second near-infrared (NIR-II) window. By employing dithieno[3,2-b:2',3'-d]pyrrole (DTP) and indolium (In) as the strong donor and acceptor, respectively, the compound DTP-In exhibits a substantial redshift in absorption and fluorescent emission reach to NIR-II region. The reduced energy gap between singlet and triplet states in DTP-In also increases the reactive oxygen species (ROS) generation rate. Further, DTP-In can self-assemble in aqueous solutions, forming positively charged nanoaggregates, which are superior to conventional encapsulated nanoparticles in cellular uptake and mitochondrial targeting. Consequently, DTP-In aggregates show efficient photodynamic ablation of 4T1 cancer cells and outstanding tumor theranostic in vivo under 660 nm laser irradiation. This work highlights the potential of molecular engineering of donor-acceptor AIE PSs with multiple functionalities, thereby facilitating the development of more effective strategies for cancer therapy.


Subject(s)
Infrared Rays , Photochemotherapy , Photosensitizing Agents , Reactive Oxygen Species , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Reactive Oxygen Species/metabolism , Photochemotherapy/methods , Animals , Mice , Cell Line, Tumor , Humans , Indoles/chemistry , Indoles/pharmacology , Nanoparticles/chemistry , Pyrroles/chemistry , Pyrroles/pharmacology
19.
Nano Lett ; 24(11): 3347-3354, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38451030

ABSTRACT

Understanding the photosensitization mechanisms in Yb3+-doped perovskite nanocrystals is crucial for developing their anticipated photonic applications. Here, we address this question by investigating near-infrared photoluminescence of Yb3+-doped mixed-halide CsPbClxBr3-x nanocrystals as a function of temperature and revealing its strong dependence on the stoichiometry of the host perovskite matrix. To explain the observed experimental trends, we developed a theoretical model in which energy transfer from the perovskite matrix to Yb3+ ions occurs through intermediate trap states situated beneath the conduction band of the host. The developed model provides an excellent agreement with experimental results and is further validated through the measurements of emission saturation at high excitation powers and near-infrared photoluminescence quantum yield as a function of the anion composition. Our findings establish trap-mediated energy transfer as a dominant photosensitization mechanism in Yb3+-doped CsPbClxBr3-x nanocrystals and open up new ways of engineering their optical properties for light-emitting and light-harvesting applications.

20.
ACS Nano ; 18(11): 8157-8167, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38456777

ABSTRACT

Perovskite light-emitting diodes (PeLEDs) are the next promising display technologies because of their high color purity and wide color gamut, while two classical emitter forms, i.e., polycrystalline domains and quantum dots, are encountering bottlenecks. Weak carrier confinement of large polycrystalline domains leads to inadequate radiative recombination, and surface ligands on quantum dots are the main annihilation sites for injected carriers. Here, pinpointing these issues, we screened out an amphoteric agent, namely, 2-(2-aminobenzoyl)benzoic acid (2-BA), to precisely control the in situ growth of FAPbI3 (FA: formamidine) nanodomains with enhanced space confinement, preferred crystal orientation, and passivated trap states on the transport-layer substrate. The amphoteric 2-BA performs bidentate chelating functions on the formation of ultrasmall perovskite colloids (<1 nm) in the precursor, resulting in a smoother FAPbI3 emitting layer. Based on monodispersed and homogeneous nanodomain films, a near-infrared PeLED device with a champion efficiency of >22% plus enhanced T80 operational stability was achieved. The proposed perovskite nanodomain film tends to be a mainstream emitter toward the performance breakthrough of PeLED devices covering visible wavelengths beyond infrared.

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