Imaging Hg 2+ -Induced Oxidative Stress by NIR Molecular Probe with "Dual-Key-and-Lock" Strategy.

Mercury (Hg) is considered an extremely toxic heavy metal which is extremely harmful to both the human body and environment. In addition, Hg ²⁺ -induced oxidative stress also exerts a crucial role to play in pathophysiological mechanisms of mercury toxicity. Thus, efficient and specific fluorescent probes for imaging Hg ²⁺ -induced oxidative stress are necessary. In the present study, we rationally design a novel Hg ²⁺ -activated and ICT-based NIR emission fluorescent probe NIR-HO for sequentially monitoring the ONOO ^- level with a "dual-key-and-lock" strategy. The probe NIR-HO showed rapid response and excellent specificity and sensitivity for the detection of Hg ²⁺ and ONOO ^- in vitro. Cell imaging demonstrated that Hg ²⁺ -induced oxidative stress was involved in ONOO ^- upregulation. Also, GSH, NAC, and EDTA were employed as excellent detoxifying drugs against Hg ²⁺ -induced toxicity. Moreover, the probe NIR-HO was successfully used for imaging Hg ²⁺ and ONOO ^- in vivo. In brief, NIR-HO provides a simple and powerful approach which can be used to image Hg ²⁺ -induced oxidative stress in the pathological environment.