In the last decades Electrolyte-Gated Organic Field-Effect Transistors (EGOFETs) have gained attention for fast and disposable sensors development thanks to low-voltage operation, high sensitivity, and easy and low cost fabrication. This thesis is focused on the testing and electrical characterization of a sensor for biological molecules detection, based on an EGOFET device. The purpose of the work is to deepen the operation of the transistor, testing it in several conditions in order to evaluate the performance and the prospect of use. The measurement setup comprises a probe station and a microfluidic system, which allows a continuous flow of aqueous solution inside the EGOFET chamber.