Resonant activation in polymer translocation: new insights into the escape dynamics of molecules driven by an oscillating field
- Autori: Pizzolato, N; Fiasconaro, A; Persano Adorno, D; Spagnolo, B
- Anno di pubblicazione: 2010
- Tipologia: Articolo in rivista (Articolo in rivista)
- Parole Chiave: Polymer dynamics; Resonant activation; Oscillating fields
- OA Link: http://hdl.handle.net/10447/53658
The translocation of molecules across cellular membranes or through synthetic nanopores is strongly affected by thermal fluctuations. In this work we study how the dynamics of a polymer in a noisy environment changes when the translocation process is driven by an oscillating electric field. An improved version of the Rouse model for a flexible polymer has been adopted to mimic the molecular dynamics, by taking into account the harmonic interactions between adjacent monomers and the excluded-volume effect by introducing a Lennard–Jones potential between all beads. A bending recoil torque has also been included in our model. The polymer dynamics is simulated in a two-dimensional domain by numerically solving the Langevin equations of motion. Thermal fluctuations are taken into account by introducing a Gaussian uncorrelated noise. The mean first translocation time of the polymer centre of inertia shows a minimum as a function of the frequency of the oscillating forcing field. This finding represents the first evidence of the resonant activation behaviour in the dynamics of polymer translocation.