Reversible Electrokinetic Confinement (RECON) Device for Dynamic Confinement of Single Macromolecules and Nanoparticles

Classic nanoconfinement techniques (i.e. with nanoslits, nanochannels) are a powerful tool for performing highly parallel macromolecular manipulations.  However, these approaches use inherently fixed confinement landscapes that limit applications (e.g. preventing post-analysis recovery of molecules and in situ modulation of confinement).  We recently introduced a new method for macromolecular nanoconfinement, Reversible Electrokinetic Confinement (RECON), which induces confinement electrically via nanopatterned AC electric fields.  In this approach, an AC voltage bias (frequency in 10-100 kHz range) is applied between parallel electrode plates, with the bottom electrode plate covered by a dielectric layer patterned to form nanogroove and nanocavity apertures.  The electric field is concentrated at the cavities, giving rise to field funnels that form free-energy traps that can be modulated in real-time to confer real-time confinement tunability.   We demonstrate that our RECON approach can perform reversible capture, confinement and release of DNA, liposome vesicles and DNA nanotubes.  DNA molecules can be trapped and extended between two adjacent cavities.  Moreover, the electrical device can be driven by arbitrary user defined signals, such as signals with amplitude modulaton (to create confinement modulation on physical time-scales) or stochastic signals (which lead to a sub-diffusive dynamics).  Comparing results to molecular dynamics simulations (Espresso MD), we quantify the influence of device and polymer physics parameters on macromolecular confinement behavior.