Chemiluminescent probes for imaging H(2)S in living animals

Hydrogen sulphide (H(2)S) is an endogenous mediator of human health and disease, but precise measurement in living cells and animals remains a considerable challenge. We report the total chemical synthesis and characterization of three 1,2-dioxetane chemiluminescent reaction-based H(2)S probes, CHS-1, CHS-2, and CHS-3. Upon treatment with H(2)S at physiological pH, these probes display instantaneous light emission that is sustained for over an hour with high selectivity against other reactive sulphur, oxygen, and nitrogen species. Analysis of the phenol/phenolate equilibrium and atomic charges has provided a generally applicable predictive model to design improved chemiluminescent probes. The utility of these chemiluminescent reagents was demonstrated by applying CHS-3 to detect cellularly generated H(2)S using a multi-well plate reader and to image H(2)S in living mice using CCD camera technology.