Equilibrium and irreversible unzipping of DNA in a nanopore

We study the unzipping dynamics of individual DNA hairpins using nanopore force spectroscopy at different voltage ramp rates and temperatures. At high ramp rates the critical unzipping voltage is proportional to log V̇, where V̇ is the voltage ramp. At low ramp values we observe a crossover to another regime with a weaker dependence on V. Here we report on the dependence of these two regimes on temperature. Remarkably, the unzipping kinetics can be well described by a simple two-states model that predicts the existence of two asymptotic regimes: quasi-equilibrium unzipping at low-voltage ramps and irreversible unzipping at high ramp rates.