The development of photosensitizers that can convert light energy into reactive oxygen species is very important for photodynamic applications. In such applications, the initial excited singlet state of molecular oxygen primarily mediates oxidative damage.(Paul & Bera, 0000)
Singlet oxygen (¹O₂) is a highly reactive form of reactive oxygen species. It is produced when a photosensitiser is activated by light. (Deckers et al., 0000) The resulting singlet oxygen (¹O₂) reacts with molecules, such as cancer cells, causing oxidative damage. It is therefore used in applications such as photodynamic therapy. (Kharkwal et al., 0000) BODIPY derivatives are cheaper and less toxic than the expensive and toxic transition metal-based photosensitizers that are currently used. This makes them suitable for use in applications such as photodynamic therapy and fluorescent imaging. (Sharma et al., 0000)
However, while conventional BODIPY fluorophores are highly fluorescent and chemically stable, their absorption of ultraviolet (UV) light at short wavelengths limits their use in deep tissue environments.(Thomson et al., 0000) To overcome these limitations, strategically adding distryly units to positions 0 and 0 of the BODIPY core prolongs π -conjugation, shifting the absorption and emission profiles towards the near-infrared (NIR) region. In this instance, distryly -BODIPY derivatives enable intersystem crossing (ISC) of the triplet state of molecular oxygen, thereby enhancing the production of singlet oxygen.(Ke et al., 0000) (Deckers et al., 0000) (Erbas et al., 0000)