DNA nanotechnology typically requires idealized Mg2+ environments, but practical applications demand structural integrity in complex ionic settings. We investigate how extra divalent cations (Mg2+, Ca2+, and Mn2+) modulate the assembly and stability of DNA-brick nanofibers. While Mg2+ promotes assembly at optimal levels but induces concentration-dependent aggregation and kinetic hysteresis, Ca2+ causes progressive structural erosion. Conversely, Mn2+ acts as a potent inhibitor via nucleobase coordination. Notably, individual fiber bending profiles remain unaffected. Our results suggest that ionic radius, hydration, and coordination properties may differentially modulate DNA assembly pathways and stability.
Liu et al. (Tue,) studied this question.