Structure-induced enhancement of charge transport in DNA via bis-daunomycin intercalation.

Understanding how structural modifications influence charge transport in DNA is central to biomolecular electronics. In this study, we investigate the effect of daunomycin intercalation on DNA stability and charge transport. We employ a combination of classical molecular dynamics simulations, electronic structure calculations, and charge transport within the Landauer-Büttiker framework. The intercalation significantly enhances DNA rigidity, with bis-daunomycin providing further stabilization due to the linker. The results show that the bis-daunomycin intercalation enhances conductance by nearly threefold, despite the presence of a non-conjugated linker. The conductance enhancement arises from the cooperative interplay of linker-induced structural stabilization and intercalator-derived electronic states, with structural stabilization providing the dominant differentiating factor. Additionally, intercalation introduces daunomycin-derived states near the LUMO region, leading to a reduction in the HOMO-LUMO gap from 4.22 eV to 2.23 eV. These findings highlight the importance of structural stabilization in tuning quantum transport properties and suggest the potential of bis-intercalators for DNA-based nanoelectronic applications.