A NIR fluorescent probe for the detection and visualization of hydrogen sulfide using the aldehyde group assisted thiolysis of dinitrophenyl ether strategy

In view of the significant physiological and pathological roles H₂S plays in living systems, it is crucial to develop fluorescent probes for H₂S detection with high sensitivity and good selectivity. Herein, a novel NIR fluorescent probe NDCM-2 based on the dicyanoisophorone derivative was designed and synthesized by employing ortho-aldehyde assisted thiolysis of 2,4-dinitrophenyl (DNP) ether as the sensing strategy to achieve highly specific H₂S detection in living systems. The studies demonstrated that probe NDCM-2 exhibited excellent sensing performance toward H₂S with 160-fold NIR fluorescence enhancement, a rapid response within 15 min, excellent sensitivity with a detection limit of 58.797 nM, a large Stokes shift of 170 nm and good selectivity. In light of these unique properties, NDCM-2 has been successfully applied for the fluorescence imaging of H₂S in biological systems (living cells, tissues and mice), demonstrating that it would be an effective tool for H₂S detection in living systems.