Headspace separation-combined fluorescence strategy for highly selective detection of hydrogen sulfide using silver...

Hydrogen sulfide (H₂S) is a poisonous gas and endogenously produced signaling molecule in mammalian systems, and its highly selective and rapid monitoring is urgently desired. Nevertheless, the performance of nearly all the fluorescence probes for H₂S detection is limited by interferences caused by other non-volatile thiol-containing species. To address this issue, herein, a headspace separation-combined fluorescence strategy was attempted by utilizing thiosalicylic acid (TSA)-capped silver nanoclusters (AgNCs@TSA) as probes. AgNCs@TSA showed a significant aggregation-induced emission (AIE) phenomenon; Moreover, upon the introduction of H₂S, the responsive disassembly of its aggregates occurred due to the competitive Ag-sulfur bond formation between H₂S and TSA molecules on the surface of the AgNCs, accompanied by a distinctive luminescence quenching. Using hybrid analysis, superior selectivity could be obtained, and the signal change (ΔI) of AgNCs@TSA showed good linearity at an H₂S concentration of 0.1-100 μM with a detection limit (3σ) of 72.2 nM. In monitoring sulfide levels in real samples, the approach yielded recoveries from 98.3% to 103.7% with a relative standard deviation (RSD) of less than 3.1%. The approach described here may be readily extended to the analysis of other volatile components, with the advantage of easy elimination of interferences. Furthermore, the hybrid optical strategy is expected to be a flexible and versatile platform for the on-site detection of volatile components.