जर्नल ऑफ़ क्लिनिकल पैथोलॉजी एंड लेबोरेटरी मेडिसिन


A dicyanoisophorone-based highly sensitive and selective near infrared fluorescent probe for sensing thiophenol in water samples and living cells

Yuanqiang Hao

Thiophenol (C6H5SH, PhSH) is a widely used aromatic organosulfur in organic synthesis and in industrial chemistry. Therefore, facile and effective detection of this irritant and toxic compound is highly desired for environmental monitoring and assessment. Herein, we reported a novel nearinfrared (NIR) probe (1) for fluorescence turn-on detection of PhSH. The probe was obtained by coupling 2, 4-dinitrophenyl (DNP) to a hydroxy-substituted dicyanoisophorone based D–π–A fluorophore. PhSH can specifically mediated a nucleophilic aromatic substitution (SNAr) reaction with probe 1 to release the D–π–A fluorophore, thus achieving a dramatic turn-on NIR fluorescence response (~200 fold, λem=693 nm) and a dramatic colour change of the probe solution from red (λabs=524 nm) to blueness (λabs=668 nm). This fluorescent assay based on probe 1 displayed a large Stokes shift (~133 nm) and a high sensitivity for PhSH sensing with a low detection limit of 34 nM. Moreover, probe 1 was successfully applied to monitor PhSH in real water samples as well as imaging PhSH in living cells.