Selective electrochemiluminescent detection of sulfide based on a dual- quenching cyclometalated Ir(III) complex

摘要

Hydrogen sulfide (H_2S) is known to be an important mediator of diverse cellular functions in health and in disease. It is of great importance to develop a selective and efficient detection method for H_2S. Herein, we report an iridium-based electrochemiluminescent (ECL) sulfide probe (1) composed of the acrylate and dini-trobenzenesulfonyl (DNBS) units as both reactive and quenching groups. While control probes (2 and 3) having either acrylate or a DNBS group exhibited moderate selectivity for sulfide and other biothiols, the dual-quenching chemodosimetric ECL probe 1 installed with both acrylate and DNBS units enabled selective sensing of sulfide anions over various anions and biothiols with high turn-on ratio. The sensing mechanism of probe 1 was elucidated using MALDI-TOF mass and ~1H NMR analyses. Probe 1 was successfully applied to the detection of H_2S in human serum by the ECL method. This ECL-based detection method can be developed into a point-of-care testing method for selective sensing of sulfide.