Orientational Binding and Directional Transport of DNA on Nano-Heterojunctions
A deep understanding of the interactions between nanomaterials and biomolecules is critical for biomedical applications of nanomaterials. In this paper, we studied the binding patterns, structure stabilities and diffusions of a double stranded DNA (dsDNA) segment on two recently reported graphene derivatives, boronic graphene (C3B) and nitrogenized graphene (C3N), with molecular dynamics (MD) simulations. Our results demonstrate that dsDNA exhibits a highly favored binding mode with an upright orientation on the C3B and C3N, independent of the initial configurations. In contrast to graphene (GRA) which demonstrates a cytotoxic feature, the C3B and C3N show high biocompatibility without causing evident structure distortions to dsDNA duplex, benefitted from the periodic atomic charge distributions. Most interestingly, a highly directional dsDNA transport is realized by formation of C3B/GRA and C3N/GRA in-plane heterojunctions, where the dsDNA migrating direction is uniformly C3B→GRA→C3N. Furthermore, free energy profiling calculated by the umbrella sampling technique quantitatively supports these observations. The insights from our study would potentiate and guide the future studies of graphenenic 2D materials and bring about a flourishing new branch of the in-plane heterojunction applications as targeted drug delivery templates in biomedical researches.