Electrochemiluminescent chemodosimetric probes for sulfide based on cyclometalated Ir(III) complexes

We developed two electrochemiluminescent probes (1, 2) for sulfide (S2-), based on cyclometalated Ir(III) complexes. Addition of sulfide anions greatly increased the ECL signal of probes by cleaving a PET quencher moiety from probe ligands. Probe 2 showed a high turn-on ratio of ECL and good selectivity for sulfide anions over various anions and biothiols.