Near-infrared AIE chemiluminescence probe for monitoring and evaluating singlet oxygen in vivo.

The incorporation a "singlet oxygen (O) battery" into photodynamic therapy (PDT) could overcome the deficiency of tumor hypoxia in PDT and enhance its effect. However, real-time monitoring the O release efficiency of the O battery still presents a significant challenge in vivo. To address this issue, we have developed a bright aggregation-induced emission (AIE) chemiluminescence (CL) probe (DTLum), which conjugates a luminol unit with a donor-acceptor structured diketopyrrolopyrrole fluorophore, for the specific detection of O. Subsequently, the DTLum nanoparticles (DTLum NPs) were prepared using PEO-PPO-PEO (Pluronic F127) as the surfactant. The DTLum NPs can detect O in aqueous solution with a bright near-infrared (NIR) CL signal (651 nm) and great tissue penetration (12.5 mm), making them suitable for the detection of O both in vitro (quantitative) and in vivo (qualitative). Notably, by utilizing the DTLum NPs, the process of O release in O batteries with different release rates can be visually monitored in cells and in vivo. This NIR CL probe provides a powerful platform for real-time monitoring and evaluating the release efficiency of O battery.