Described are methods for detecting a target analyte in a test sample by providing a solid support comprising an electrode comprising: (i) a self-assembled monolayer (SAM), (ii) a covalently attached electroactive active moiety (EAM) comprising a transition metal complex comprising a self-immolative moiety and a peroxide sensitive moiety (PSM), wherein said EAM has a first E0; then contacting the target analyte and said solid support under conditions wherein said target analyte reacts with a peroxide generating enzyme to generate peroxide and said self-immolative moiety is removed such that said EAM has a second E0 test sample; and then detecting said second E0 as an indication of the presence of said target analyte. Also provided are compositions for use in the preceding methods.