Abstract: The present invention relates to an electrochemical sensor for the detection of biological molecules and a process for the production thereof. In the sensor, an electrode system comprising at least one working electrode (1), one counter electrode (3) and a reference electrode (4) operate inside of a reaction camber (18). The reaction chamber (18) is intended to contain a system of reagents in solution, comprising at: least one electrochemical mediator Said working electrode is made of series of nanoelectrodes (11, 12) of a noble metal, inserted in an isolating layer (10) consisting of a resin suitable for lithography and nano-lithography, functionalised or functionalisable for the binding to biological molecules to be detected. The invention further refers to a kit comprising said sensor and a process for the production thereof.