  Using neutron reflectivity together with an appropriate electrochemical cell,
we have studied the effects of transverse electric field on the Bovine Serum
Albumin (BSA) monolayer initially adsorbed at the interface of the aqueous
solution and a conductive doped-silicon wafer. Depending on the sign of the
initial potential, a second layer is adsorbed on top of the first whereas a
subsequent reversal of potential has no effect. We show that this behavior
reveals the slow and remanent electric polarization of the first BSA layer and
suggest an analogy with spin glasses based on the dipolar structure of this
protein.
