Near-Infrared Chemiluminescent Probe for Real-Time Monitoring Singlet Oxygen in Cells and Mice Model.

Singlet oxygen (1O2) plays a vital role in metabolism. However, because of its extremely high reactivity and short-lived state, the in vivo detection of 1O2 is challenging. To address this issue, for the first time, we herein constructed a near-infrared (NIR) chemiluminescent probe (CL-SO) by caging the precursor of phenoxy-dioxetane scaffolds and a dicyanomethylchromone acceptor for selective 1O2 detection. This probe can detect 1O2 in vitro with a tremendous turn-on chemiluminescence signal in the NIR region (700 nm) and image intracellular 1O2 produced by the photosensitizer during the simulated action of photodynamic therapy (PDT). Notably, 1O2 level changes in the abdominal cavity and tumor of the various mice model under different stimulations and PDT action were effectively monitored by CL-SO, providing a novel chemiluminescence imaging platform to explore 1O2 generation in PDT-associated applications.