A comparative evaluation of an electrochemical sandwich genoassay for pathogenic bacteria based on immobilized hairpin DNA probes and three different enzyme labels (horseradish peroxidase, alkaline phosphatase and a biomimetic peroxidase-like DNAzyme) is reported. The natural enzymes were used as streptavidin conjugates, coupled to the surface duplex by using a biotin-labeled signaling probe, whereas the DNAzyme was directly incorporated to the sequence of the signaling probe. HRP provides enhanced sensitivity although the choice of a catalytic reporter DNA sequence could simplify the assay.