Self-Assembly of DNA Homopolymers by Pathway Dependence to Evade Metastable States

A pathway-dependent strategy is proposed to assist single-stranded DNA polyadenine (poly(dA)) in evading metastable states and to achieve morphological regulation from microcapsules to microbowls by fractional n-butanol addition and emulsification (shaking) in a soft emulsion template (water-in-n-butanol). The first stage is the formation of small microcapsules by a fourth solvent addition and shaking. The second stage is the expansion of the small microcapsules initiated by the fifth solvent addition and shaking, drawing them to a new pathway to evade metastable states. Osmotic re-equilibrium and shaking are two indispensable conditions for overcoming the energy barriers. The third stage is the buckling of the expanded microcapsules and the evolution into microbowls after the evaporation of n-butanol to reach a global free energy minimum stable state. Conversely, the conventional one-time solvent addition and shaking pathway do not obtain microbowls. This kinetics pathway-dependent strategy evades metastability and shapes DNA oligonucleotides into desired structures via self-assembly.