The present work illustrates results obtained using dielectric impedance spectroscopy for adsorption monitoring of macromolecules like bovine serum albumin (BSA) onto insulated polymer in microchip. BSA does not need to be labeled but it must be attached to the polymer surface coupled with the microelectrodes. Modeling the microchip interface using an appropriate equivalent circuit allowed us to extract the value of the interfacial impedance for ultralow protein concentrations. The promising results were obtained with this methodology making it competitive in comparison with other transductions for bioanalytical developments.