| Abstract: | We report unique findings on the voltage dependence of protein exclusion
from the pores of nanoporous polymer exclusion membranes. The pores are
small enough that proteins are excluded from passage with low applied
electric fields, but increasing the field enables proteins to pass
through. The requisite field necessary for a change in exclusion is
protein-specific with a correlation to protein size. The field-dependence
of exclusion is important to consider for preconcentration applications.
The ability to selectively gate proteins at exclusion membranes is also a
promising means for manipulating and characterizing proteins. We show
that field-gated exclusion can be used to selectively remove proteins
from a mixture, or to selectively trap protein at one exclusion membrane
in a series. |