In this work, an ab-initio study of the electrical response to odorants of a self-assembled monolayer of a pig OBP immobilized onto a miniaturized Si-substrate equipped with gold interdigitated electrodes (IDE), was started. Electrical impedance spectroscopy (EIS) was used as electrical characterization technique and a dedicated experimental set-up was arranged in order to carry out EIS measurements in controlled environment. The EIS data was fitted by using a fitting software based on Levenberg-Marquardt (LEVM) algorithm to determine the equivalent circuit of the system.