A novel ratiometric luminescent probe based on a ruthenium(II) complex-rhodamine scaffold for ATP detection in cancer cells.

Adenosine 5'-triphosphate (ATP) plays a pivotal role as an essential intermediate in energy metabolism, influencing nearly all biological metabolic processes. Cancer cells predominantly rely on glycolysis for ATP production, differing significantly from normal cells. Real-time in situ monitoring and rapid response to intracellular ATP levels offers more valuable insights into cancer cell physiology. Herein, we report a novel ratiometric luminescent probe, Ru-Rho, comprised of a ruthenium(II)-based complex and rhodamine 6G (Rho 6G) with excellent water solubility and photostability. Notably, Ru-Rho selectively responds to ATP at acidic conditions, matching the need of monitoring ATP under the acidic intracellular environment of cancer cells. Moreover, the fast ratiometric detection and imaging of ATP under single wavelength excitation improve the detection accuracy. Ru-Rho has been effectively utilized not only for ratio imaging ATP in cells and zebrafish, but also for assessing the efficacy of glycolysis-inhibiting anticancer drugs in intracellular levels, which accelerates the screening process for anticancer drugs and supports the development of new therapeutic agents. The design strategy based on transition metal ruthenium(II) complexes opens a new pathway for constructing ATP luminescent probes, allowing for better adaptation to complex detection requirements.