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

The incorporation a “singlet oxygen (¹O₂) battery” into photodynamic therapy (PDT) could overcome the deficiency of tumor hypoxia in PDT and enhance its effect. However, real-time monitoring the ¹O₂ release efficiency of the ¹O₂ 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 ¹O₂. Subsequently, the DTLum nanoparticles (DTLum NPs) were prepared using PEO₁₀₀-PPO₆₅-PEO₁₀₀ (Pluronic F127) as the surfactant. The DTLum NPs can detect ¹O₂ 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 ¹O₂ both in vitro (quantitative) and in vivo (qualitative). Notably, by utilizing the DTLum NPs, the process of ¹O₂ release in ¹O₂ 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 ¹O₂ battery. © 2024 Elsevier B.V.