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

Abstract

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.

Keywords: Detection; Dual-signal; Hydrogen sulfide; Imaging; Probe.