A fluorescent probe capable of naked eye recognition for the selective detection of biothiols

Abstract A novel fluorescent turn-on probe for rapid optical sensing of thiols was designed and synthesized. The probe exhibits a high fluorescence switching signal ratio and high selectivity to thiols with the naked eye and can identify biological thiols in cells. The biothiol cleaves the 2,4-dinitrobenzenesulfonyl group to release the fluorophore under PBS (10 mM, pH = 7.4) aqueous buffer solution. The probe is intrinsically nonfluorescent; however, after being reacted with thiols, it elicits a significant NIR fluorescent turn-on response. Probe displays 55-fold fluorescence intensity enhancement at 625 nm. More importantly, the probe features a good linearity range and the detection limits of the probe for Cys, Hcy and GSH were 1.47, 2.4 and 2.27 μmol·L-1, respectively. The probe showed excellent anti-interference ability and the imaging of thiols in living cells is demonstrated. All these good properties proved it to be a good sensor for the selective detection of thiols and a potential use in biological applications.