The possibility of singlet oxygen (0
O0) generation by donor−
acceptor dyads has not been realized so far in a practical sense. It
could be expected that 0
O0 generation by PeT-based optical
probes in biological environments would affect their optical
response and simultaneously induce cytotoxicity. This is of
concern especially in the case of ROS detection, where
sensitization of 0
O0 by the probe itself may lead to false positives
and incorrect interpretations.0 On the other hand, PeT-mediated 0
O0 generation could provide a new tool for theranostic