A novel "turn-on" mitochondria-targeting near-infrared fluorescent probe for H2S detection and in living cells imaging

Abstract

Hydrogen sulfide (H₂S) has been considered to be involved in cytoprotective processes and redox signaling. It is very meaningful to track and analyze it in mitochondria. Herein, we report a novel "turn-on" mitochondria-targeting near-infrared fluorescent probe (Mito-NIR-SH) for detection of H₂S in living cells, which was designed and synthesized by introducing 2,4-dinitrophenyl as fluorescence quenching group and H₂S response moiety into Changsha near-infrared fluorophore (CS-OH). The structure of the fluorophore and the probe were characterized by ¹H NMR, ¹³C NMR and mass spectrometry. Meanwhile, Mito-NIR-SH could quantitatively detect H₂S at concentrations ranging from 0 to 30 μM with a detection limit as low as 89.3 nM, showing good chemical stability, fast "turn-on" response, selectively mitochondrial location, as well as high sensitivity and selectivity toward H₂S. Based on this, it was successfully applied to imaging exogenous and endogenous H₂S in living HeLa cells via confocal fluorescence microscopy.

Keywords: Bioimaging; High sensitivity and selectivity; Hydrogen sulfide; Mitochondria-targeting; Near-infrared fluorescent probe.