A ratiometric fluorescence probe for the selective detection of H2S in serum using a pyrene-DPA–Cd2+ complex

A ratiometric and selective hydrogen sulfide (H2S) detection probe was proposed based on the pyrene-DPA–Cd2+ complex through the metal ion displacement approach (MDA) mechanism. While most MDA-based fluorescence probes with paramagnetic Cu2+ have focused on the development of a simple turn-on sensor using the broad spectral range of fluorescence enhancement, this ratiometric probe exhibited unchanged monomer emission as a built-in internal reference with an increase in excimer emission with added H2S. The demonstrated probe showed a rapid response (within 1 min) and a high sensitivity, with 70 nM as the limit of detection. The selectivity for H2S over cysteine, homocysteine and glutathione was confirmed, and reliable fluorescence enhancement, which could be monitored by the naked eye, was observed upon irradiation with handheld UV light. In addition, this detection system was successfully applied to detect H2S in human serum without interference from biological molecules.