A Visible and Near-Infrared, Dual-Channel Fluorescence-On Probe for Selectively Tracking Mitochondrial Glutathione

Abstract

Glutathione is a major endogenous antioxidant in biological systems. As a result, highly selective fluorescent probes are significant components of studies aimed at gaining a better understanding of the role(s) glutathione plays in biological functions. In this study, we developed a dual-channel turn-on fluorescent probe for glutathione, comprising naphthalimide and cyanine, bridged by a thiol-reactive sulfonamide moiety. The probe selectively responds to glutathione and is not affected by cysteine and homocysteine. Important information has been gained about the chemical mechanism for operation of the probe, which responds to glutathione in visible and near-infrared channels synchronously and independently. Moreover, this probe exhibits the remarkable capability of targeting mitochondria and dual-channel tracking of intracellular glutathione in a spatiotemporal and synchronous manner. We believe that the strategy used to design the new dual-channel fluorescence-on probe will be applicable to the design of fluorescent probes that display specific responses in multiple channels. © 2018 Elsevier Inc.Glutathione (GSH), as the most abundant intracellular biothiol, participates in many physiological processes. Aberrant levels of cellular GSH are closely associated with a variety of diseases, so GSH can be considered a significant biomarker for the health of humans. Accordingly, developing specific fluorescent probes to assess the cellular function and distribution of GSH is of great significance. Here, a unique sensing model is accomplished; the developed probe displays high selectivity toward glutathione in both visible and near-infrared channels, and the sensing mechanism is elucidated. Bioimaging shows that this probe possesses excellent capability for mitochondria localization and can selectively monitor intracellular glutathione in dual channels in a spatiotemporal and synchronous manner.A naphthalimide- and cyanine-dressing fluorescent probe is utilized to specifically and selectively detect glutathione in both visible and near-infrared channels, respectively. Cell imaging indicates that this probe can target mitochondria and track intracellular glutathione in dual channels in a spatiotemporal and synchronous manner.