A symmetric pyrylium based near-infrared probe with large Stokes shift for detection of H2S in water, food, and living cells

H2S has attracted significant attention as an important gasotransmitter or gasomediator due to its essential roles in many pathological and physiological processes in living systems, and due its being one of the compounds involved in food production and spoilage. The real-time detection/visualization of H2S levels in practical samples is of great significance for environmental monitoring, food engineering, and biological analysis. In this study, for the first time, a symmetric pyrylium HN9 dye was designed and synthesized. The new HN9 dye possessed nearinfrared emission at 688 nm, a large Stokes shift of 83 nm, and good brightness for high fidelity and low excitation interference testing. Thus, the HN9 dye was employed to prepare a representative HN9DNP probe for the detection H2S. By regulating a photoinduced electron transfer mechanism, the H2S probe exhibited a 24-fold fluorescence enhancement, a linear detection range of 0-30 mu M, and a good detection limit of 0.48 mu M. Moreover, the HN9DNP probe was successfully applied for sensing H2S in environmental water samples, cell lysates, food samples, and living cells, which provided an efficient approach for the highly sensitive and selective detection of H2S in practical applications.