Devices based on nanostructures, such as nanogaps and nanowires, are widely employed in bio-sensing, for example building a sensing nanowire structure on a nanogap between two electrodes. The main difficulty in the fabrication process of these structures is due to the fact that the nanogap between the electrode is created starting from a continuous structure and then using electromigration, but this process is random and so non-controllable. Moreover the positioning of the nanowire right in the middle of the gap is quite challenging. In this work, starting from the fabrication of the devices (based on a previous work and slightly modified), different tests on the devices are performed, starting from measuring the resistance of the nanowire itself, to a detection of human fibrinogen.