Detection of hydrogen sulphide based on a novel G-quadruplex selective fluorescent probe

It is of great importance to detect hydrogen sulfide (H2S) simply and sensitively for its role in various physiological processes as well as its inherent toxicity. In this work, two 3-Hydroxychromone (3HC) derivatives were prepared from 3HC-N3 based on HS− mediated reduction of azides, which was found to recognize G-quadruplexes (G4) with strong fluorescence emission through strong π-π stacking interactions and hydrogen bonding. Moreover, the mixture of 3HC-N3 and G4 was used as the H2S sensor with a limit of detection (LOD) as low as 2.64 nM in aqueous solution, which was much lower than most of current approaches. Given the fine performances and striking properties, this G-quadruplex-selective fluorescent turn-on probe would achieve a promising application of H2S detection in low fluorescence interfering environment samples.