The increase in
the Rct values after the antibody-antigen binding may also be
correlated with the fact that increasing antigen-antibody binding
events eventually block the free spaces on the bioelectrode. The
immunosensor configuration resembles a capacitor in its ability to
store charge wherein the antibody molecules act as dielectric layer.
The parameter Rct is related to the dielectric and insulating features
at the electrode/electrolyte interface, hence they are affected by the
changes at the electrode surface