Self-Illuminating\nCopper-Luminol Coordination Polymers\nfor Bioluminescence Imaging of Oxidative Damage

Timely detection of reactive oxygen species (ROS) accumulated\nduring\ninflammation is essential for an early disease diagnosis. Compared\nto fluorescence probes with limited sensitivity and accuracy, chemiluminescence\n(CL) imaging offers the potential for highly sensitive molecular visualization\nof ROS by minimizing background interferences. However, the development\nof bright and easily manufacturable CL probes for ROS imaging remains\nchallenging. In this study, a novel chemiluminescent nanoprobe named\nCu-Lum@NPs for ROS imaging in inflammation was synthesized by using\na one-step solvothermal method. The Cu-Lum@NPs, which are composed\nof coordination polymers containing copper ions and luminol (Lum), demonstrate intrinsic\nperoxidase-like activity that relies on Cu(I) as the catalytic active\ncenter to initiate the Fenton reaction. This catalytic process facilitates\nthe decomposition of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) into hydroxyl radicals (•OH) and superoxide anion radicals\n(O<sub>2</sub><sup>•–</sup>), leading to the oxidation\nof Lum and inducing strong luminescence. Cu-Lum@NPs, displaying nanozyme\ncharacteristics, were observed to accelerate and enhance the ROS-responsive\nluminescence (10–1600-fold in solution and over 100-fold in\nneutrophils) and notably extend persistent luminescence. The Cu-Lum@NPs\nallowed for CL imaging of endogenous ROS in living cells and animals\nwith an outstanding signal-to-noise ratio exceeding 96 and facilitated\noxidative damage luminescence imaging for tissue-specific detection.\nThe study presents Cu-Lum@NPs, a highly sensitive and easily manufacturable\nchemiluminescent nanoprobe for ROS imaging both <i>in vitro</i> and <i>in vivo</i>, exhibiting enhanced luminescence and\nprolonged persistence for ROS-related disease detection.