Stability of an aqueous quadrupole micro-trap.

The recently demonstrated functionality of an aqueous quadrupole micro- or nano-trap opens a new avenue for applications of Paul traps, like confinement of a charged biomolecule which requires a water environment for its chemical stability. Besides the strong viscosity forces, the motion of a charged particle in the aqueous trap is subject to dielectrophoretic and electrophoretic forces. In this study, we describe the general conditions for stability of a charged particle in an aqueous quadrupole trap. We find that for typical micro-trap parameters, the effects of both dielectrophoresis and electrophoresis significantly influence the trap stability. In particular, an aqueous quadrupole trap could play the role of a synthetic virtual nanopore for the third generation of DNA sequencing technology.