Potential Unwinding of Double-Stranded DNA upon Binding to a Carbon Nitride Polyaniline (C₃N) Nanosheet

Recently, carbon nitride polyaniline (C₃N) had attracted considerable attention from many scientific fields after its successful synthesis. However, thus far, limited efforts were devoted to reveal its potential effect to biomolecules, which correlated intimately with its further utilization. In this study, by using a molecular dynamics (MD) simulation approach, we investigated in detail the interaction between C₃N and a double-stranded DNA (dsDNA) segment to expose the underlying biological effect of C₃N to dsDNA and the corresponding molecular basis. MD simulation results demonstrated that dsDNA presented serious damages upon adsorption onto a C₃N nanosheet with the terminal base pairs denaturized, unwound, and directly packing on the C₃N surface, which implied that C₃N was potentially deleterious to biomolecules. This binding/unwinding process was mainly guided by a combination of van der Waals and π-π stacking interactions together with a continuous lateral migration of dsDNA. Moreover, the nanoscale dewetting also played an important role during the adsorption. These findings revealed the potential bio-effect of the C₃N nanomaterial and its molecular mechanism, which might benefit the future applications of C₃N-based nanostructures.