In silico investigation of a series of D-A-D structured chain thiophene photosensitizers for photodynamic therapy

Abstract This study investigated the therapeutic activity of a series of chain thiophene photosensitizers (PS) using theoretical simulation approaches. Density functional theory and its time-dependent extension (DFT, TD-DFT) were used to calculate the parameters for the determination of various photophysical properties of PSs, such as electronic absorption spectrum, singlet-triplet state energy gap, and to discuss the electron-hole relationship between excited states and orbitals. The calculations show that these photosensitizers have a practical inter-system crossing (ISC) transition from the first singlet excited state to the lower triplet state excited state with sufficient energy to produce reactive oxygen species (ROS). These suitable properties make these series of PSs promising for photodynamic therapy (PDT) applications. these photosensitizer molecules in this work can provide a theoretical reference for further experimental researches.