A DNAzyme-Based Nanoprobe for "Visual" Decorporation of Uranyl In Vivo

Uranium poses severe health risks due to its chemo- and radiotoxicities, particularly during nuclear accidents. Despite recent advances in uranyl decorporation agents, clinically effective agents remain scarce. The optimization of uranium decorporation agents is severely impeded partially because the current assessment methods are complicated and time-consuming, which often results in delayed feedback. Real-time, visualized monitoring techniques are critically needed to advance chelation therapy. Here, we strategically developed a uranyl-specific DNAzyme-based "turn-on" nanoprobe for visualizing uranium decorporation in vivo. The probe features a fluorophore and its quencher attached to different DNAzyme ends, which separate upon uranyl-induced selective cleavage, resulting in the recovery of the fluorescence emission intensity. In uranium-exposed mice, the nanoprobe detected the deposited uranyl in kidneys with 1.8-fold enhanced emission intensity versus that of controls, demonstrating excellent in vivo imaging capability. Importantly, the probe successfully distinguished uranyl content differences in contaminated mice treated with or without the decorporation agent, providing a rapid evaluation of treatment efficiency. These findings establish DNAzyme@QDots as an effective biological probe for real-time visualization of uranyl decorporation and signify its future application in nuclear emergency response.