Condensation and demixing in solutions of DNA nanostars and their mixtures

We present a novel numerical/theoretical approach to efficiently evaluate the phase diagram of self-assembling DNA nanostars. Combining input information based on a realistic coarse-grained DNA potential with the Wertheim association theory we derive a parameter-free thermodynamic description of these systems. We apply this method to investigate the phase behaviour of single-component and mixtures of DNA nanostars with different number of sticky arms, elucidating the role of the system functionality and of salt concentration. Specifically, we evaluate the propensity to demix, the gas-liquid phase boundaries and the location of the critical points. The predicted critical parameters compare very well with existing experimental results for the available compositions. The approach developed here is very general, easily extensible to other all-DNA systems and provides guidance for future experiments