Figure 5.

Basic principles of chemiluminescence-mediated photodynamic therapy as an alternative to treatment using external light sources. While in direct chemiluminescence, the excited material (CL) itself is capable of emitting light, during the process of indirect chemiluminescence, the energy is passed from the chemiexcited molecule (the intermediate (INT)) to another molecule (known as the acceptor or fluorophore (FL)) which becomes further excited. The emitted energy is absorbed by the photosensitizer (PS), activating it.