A simple fluorescent probe with two different fluorescence signals for rapid sequence distinguishing of Cys/Hcy/GSH and intracellular imaging

Abstract

Based on the 7-nitro-1,2,3-benzoxadiazole (NBD) unit, many fluorescent probes have been developed for the differential detection of biothiols. Among them, however, the use of fluorescent probes for rapid simultaneous identification of biothiols in vivo has been rarely reported. In this work, a simple fluorescent probe (NC-NBD) is rationally designed and developed according to the different reactivity of biothiols, which can simultaneously distinguish homocysteine (Hcy), cysteine (Cys), and glutathione (GSH) by adjusting two different fluorescence signals (green and yellow). The probe NC-NBD can discriminatively detect biothiols using two fluorescence channels with fast response (120–360 s), which is suitable for real-time monitoring of biothiols in biological systems. As expected, the probe NC-NBD with excellent performance is able to determine the levels of Cys/Hcy and GSH in human serum samples, and therefore has potential applications in biological specimens. The robust probe shows low toxicity and high sensitivity when applied to living cells, and successfully achieves rapid sequence distinguishing of biothiols and intracellular imaging by using two different fluorescence signals. The probe can provide an effective tool for the real-time monitoring of intracellular biothiols.