1 research outputs found
Highly Efficient Photosensitizers with Molecular Vibrational Torsion for Cancer Photodynamic Therapy
The development of
highly effective photosensitizers (PSs) for
photodynamic therapy remains a great challenge at present. Most PSs
rely on the heavy-atom effect or the spin–orbit charge-transfer
intersystem crossing (SOCT-ISC) effect to promote ISC, which brings
about additional cytotoxicity, and the latter is susceptible to the
interference of solvent environment. Herein, an immanent universal
property named photoinduced molecular vibrational torsion (PVT)-enhanced
spin–orbit coupling (PVT-SOC) in PSs has been first revealed.
PVT is verified to be a widespread intrinsic property of quinoid cyanine
(QCy) dyes that occurs on an extremely short time scale (10–10 s) and can be captured by transient spectra. The PVT property can
provide reinforced SOC as the occurrence of ISC predicted by the El
Sayed rules (1ππ*–3nπ*),
which ensures efficient photosensitization ability for QCy dyes. Hence,
QTCy7-Ac exhibited the highest singlet oxygen yield (13-fold higher
than that of TCy7) and lossless fluorescence quantum yield (ΦF) under near-infrared (NIR) irradiation. The preeminent photochemical
properties accompanied by high biosecurity enable it to effectively
perform photoablation in solid tumors. The revelation of this property
supplies a new route for constructing high-performance PSs for achieving
enhanced cancer phototherapy