Nanowire based platforms are widely reported for sensing applications and for their potential in the bio-detection field. In the present work, memristive nanowire devices are implemented for label-free sensing in liquid samples as well as in dried samples via leveraging the modification of the hysteresis in the devices electrical response as a consequence of the surface modification. First, pH sensing in liquid conditions is demonstrated. In addition, the memristive devices are bio-functionalized using antibodies for Prostate Specific Antigen (PSA) as case of study. In this way, the nanowires are converted to memristive biosensors paving the way for future molecular diagnostics applications in general, and for detection of prostate cancer disease in particular.