Intercalator-dependent modulation of charge transport in DNA

DNA's intrinsic structural flexibility limits its application in nanoelectronics. Here, we investigate the effect of molecular intercalation on the electronic and charge-transport properties of DNA using density functional theory combined with non-equilibrium Green's function and Landauer–Büttiker approaches. Three experimentally derived intercalated systems containing Ru-complexes, daunomycin (including bis-daunomycin), and proflavine were analysed and compared with native DNA. The results show that intercalation significantly alters DNA conductance by up to two orders of magnitude, depending on the intercalator. Ru-complexes and daunomycin enhance conductance through reduced HOMO–LUMO gaps and improved orbital delocalisation, whereas proflavine suppresses hole transport by introducing localised states and disrupting π-stacking interactions. These findings demonstrate that intercalation provides an effective strategy for tuning the electronic behaviour of DNA and highlights its potential for DNA-based nanoelectronic applications.