Reversible AIE-active fluorescent probe with a large emission peak shift for ratiometric detection of food freshness indicator H2S.

It is crucial to on-site monitor H2S for addressing the concerns associated with food safety. We rationally prepared an AIE-active fluorescent probe (CLBZ) with the aggregated state conversion for sensing H2S in a ratiometric response manner. CLBZ displayed ratiometric response, fast response time (5 s), well-resolved emission peak shift (147 nm) and high selectivity towards H2S, and it can be used as a reversible and reusable probe. The probe-based test strip was also developed to conveniently detect H2S generated during food spoilage in the absence of laboratory instruments. It achieved the consistent results and sensitivity with that determined by the colony forming unit (CFU) assay. These results paved a successful way to develop an effective analytical method for food quality and safety.