Polypyrrole (pPy) thin films were synthesized electrochemically by a pulse method on platinum electrodes in N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid (PYR 14TFSI). The pulse deposition method allowed the synthesis of well adherent pPy layers on Pt that are attractive for the realization of sensors and biosensors because of their good selectivity with respect to the most common interferants. The EIS (Electrochemical Impedance Spectroscopy) response to hydrogen peroxide and biological interferants indicated pPy as a highly sensitive electrochemical platform for the impedimetric sensing of H 2O 2. The polymer was overoxidized (opPy) before the characterization to prevent its electrochemical contribution in aqueous solution. Then opPy was functionalized by glucose oxidase enzyme and the device was assembled and tested as a impedimetric biosensor. This technique showed to have great chances to substitute classic detection methods. ©The Electrochemical Society.