Photophysical and DNA-Binding Properties of Phenoxazine-Based Push-Pull Type Organic Chromophores: Insights From DFT,...

In this work, we investigate the photophysical and DNA-binding characteristics of phenoxazine-based organic dyads comprising donor-acceptor configuration, with the goal of boosting their potential for biointeractive applications. The interaction of these dyes with calf thymus DNA was analyzed using UV spectroscopy, confirming their intercalative binding to DNA base pairs. A straightforward UV spectroscopic approach was developed to elucidate the binding mechanisms between DNA and the dyes. Furthermore, density functional theory (DFT) and time-dependent DFT calculations provided valuable insights into their electronic structures, optical parameters, and insights of frontier molecular orbitals. Molecular electrostatic potential simulations and mapping helped clarify the electron density distributions that are key for DNA interactions. Finally, molecular docking studies backed up these findings that the structural configuration of nucleic acids significantly influences the binding interactions of push-pull organic dyads, suggesting that these dyes could be promising for use in biological imaging and therapeutic applications.