A novel device and methodology for the rapid and simple label-free electrochemical detection of proteins based on screen-printed carbon electrodes (SPCEs) modified with nanoporous Al2O3 membranes is reported. The nanoporous membranes are functionalized with antibodies and followed by the immunorecognition event that gives rise to the pore blocking. The blockage inside the nanochannels is fast, pore size dependent and easy to be detected by measuring the decrease in the differential pulse voltammetric (DPV) peak current of the [Fe(CN6)]4−/3− redox specie used as indicator. The developed nanoporous membrane based device represents a simple biodetection alternative that can be extended in the future to several other immuno and DNA detection systems.