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Abstract Efficient heterogeneous photosensitizing materials require both large accessible surface areas and excitons of suitable energies and with well‐defined spin structures. Confinement of the tetracationic cyclophane (ExBox4+) within a nonporous anionic polystyrene sulfonate (PSS) matrix leads to a surface area increase of up to 225 m2g−1in ExBox•PSS. Efficient intersystem crossing is achieved by combining the spin‐orbit coupling associated to Br heavy atoms in 1,3,5,8‐tetrabromopyrene (TBP), and the photoinduced electron transfer in a TBP⊂ExBox4+supramolecular dyad. The TBP⊂ExBox4+complex displays a charge transfer band at 450 nm and an exciplex emission at 520 nm, indicating the formation of new mixed‐electronic states. The lowest triplet state (T1, 1.89 eV) is localized on the TBP and is close in energy with the charge separated state (CT, 2.14 eV). The homogeneous and heterogeneous photocatalytic activities of the TBP⊂ExBox4+, for the elimination of a sulfur mustard simulant, has proved to be significantly more efficient than TBP and ExBox+4, confirming the importance of the newly formed excited‐state manifold in TBP⊂ExBox4+for the population of the low‐lying T1state. The high stability, facile preparation, and high performance of the TBP⊂ExBox•PSS nanocomposites augur well for the future development of new supramolecular heterogeneous photosensitizers using host–guest chemistry.
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2D Nano‐Sonosensitizers Facilitate Energy Transfer to Enhance Sonodynamic Therapy
Abstract Although sonodynamic therapy (SDT) has shown promise for cancer treatment, the lack of efficient sonosensitizers (SSs) has limited the clinical application of SDT. Here, a new strategy is reported for designing efficient nano‐sonosensitizers based on 2D nanoscale metal–organic layers (MOLs). Composed of Hf‐oxo secondary building units (SBUs) and iridium‐based linkers, the MOL is anchored with 5,10,15,20‐tetra(p‐benzoato)porphyrin (TBP) sensitizers on the SBUs to afford TBP@MOL. TBP@MOL shows 14.1‐ and 7.4‐fold higher singlet oxygen (1O2) generation than free TBP ligands and Hf‐TBP, a 3D nanoscale metal–organic framework, respectively. The1O2generation of TBP@MOL is enhanced by isolating TBP SSs on the SBUs of the MOL, which prevents aggregation‐induced quenching of the excited sensitizers, and by triplet–triplet Dexter energy transfer between excited iridium‐based linkers and TBP SSs, which more efficiently harnesses broad‐spectrum sonoluminescence. Anchoring TBP on the MOL surface also enhances the energy transfer between the excited sensitizer and ground‐state triplet oxygen to increase1O2generation efficacy. In mouse models of colorectal and breast cancer, TBP@MOL demonstrates significantly higher SDT efficacy than Hf‐TBP and TBP. This work uncovers a new strategy to design effective nano‐sonosensitizers by facilitating energy transfer to efficiently capture broad‐spectrum sonoluminescence and enhance1O2generation.
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- Award ID(s):
- 2011854
- PAR ID:
- 10403304
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 35
- Issue:
- 19
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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