Abstract
Intersystem crossing (ISC) of triplet photosensitizers is a vital process for fundamental photochemistry and photodynamic therapy (PDT). Herein, we report the co-existence of efficient ISC and long triplet excited lifetime in a heavy atom-free bodipy helicene molecule. Via theoretical computation and time-resolved EPR spectroscopy, we confirmed that the ISC of the bodipy results from its twisted molecular structure and reduced symmetry. The twisted bodipy shows intense long wavelength absorption (ϵ=1.76×105 m−1 cm−1 at 630 nm), satisfactory triplet quantum yield (ΦT=52 %), and long-lived triplet state (τT=492 μs), leading to unprecedented performance as a triplet photosensitizer for PDT. Moreover, nanoparticles constructed with such helical bodipy show efficient PDT-mediated antitumor immunity amplification with an ultra-low dose (0.25 μg kg−1), which is several hundred times lower than that of the existing PDT reagents.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 16248-16255 |
| Number of pages | 8 |
| Journal | Angewandte Chemie |
| Volume | 132 |
| Issue number | 37 |
| DOIs | |
| State | Published - May 25 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: J.Z. thanks the NSFC (21673031, 21761142005, 21911530095 and 21421005), the State Key Laboratory of Fine Chemicals (ZYTS201901), the Fundamental Research Funds for the Central Universities (DUT19TD28), Dipartimento di Scienze Chimiche, Università degli Studi di Padova (Visiting Scientist) for support. B.D. thanks Dalian University of Technology for the Haitian Professorship support. L.H. and G.H. are supported by the startup funding of University of Massachusetts. Open access funding enabled and organized by Projekt DEAL.