Highly selective dual-signal readout H2S probe: Applications in monitoring of water samples, food spoilage and live cell imaging.

We present a new probe (DN) for colorimetric and fluorimetric detecting hydrogen sulfide (H2S) on the basis of the H2S-triggered thiolysis of 4-nitro-2,1,3-benzoxadiazoyl (NBD) ether. In H2O/DMSO medium (9/1, v/v, pH 7.4), the aryl ether bond in DN was cleaved by H2S via nucleophilic aromatic substitution to yield a phenolate product with lighting up red fluorescence accompanied with a distinguished color transformation from yellow to pink. Probe DN features near-infrared emission (660 nm), large Stokes Shift (168 nm), good sensitivity (LOD: 15.1 nM) and relative fast response time (5 min) for specific sensing of H2S. Conveniently, a paper strips-based test kit was developed for tracking and assessing meat freshness by monitoring the release of H2S. What is more, DN is demonstrated to image both exogenous and endogenous H2S in live cells with relative short analysis time (30-60 min), providing a new research tool for exploring the relationship between H2S and clinical diseases.