Enzymatically controlled DNA tetrahedron nanoprobes for specific imaging of ATP in tumor

Intracellular ATP is an emerging biomarker for cancer early diagnosis because it is a key messenger for regulating the proliferation and migration of cancer cells. However, the conventional ATP biosensing strategy is often limited by the undesired on-target off-tumor interference. Here, we reported a novel strategy to design enzymatically controlled DNA tetrahedron nanoprobes (En-DT) for biosensing and imaging ATP in tumor cells. The En-DT was designed via rational engineering of structure-switching aptamers with the incorporation of an enzyme-activatable site and further conjugation on the DNA tetrahedron. The En-DT could be catalytically activated by apurinic/apyrimidinic endonuclease 1 (APE1) in cancer cells, but they did not respond to ATP in normal cells, thereby enabling cancer-specific ATP biosensing and imaging in vitro and in vivo with improved tumor specificity. This strategy would facilitate the precise detection of a broad range of biomarker in tumors and may promote the development of smart probes for cancer diagnosis.