A fluorescent probe for rapid staining and real-time detection of autophagy in single cells by lighting-up G-quadruplexes

Autophagy is a crucial physiological mechanism in eukaryotes for maintaining metabolic balance, and its dysregulation is closely linked to human neurodegenerative diseases, tumors, and others. Real-time tracking of autophagy in live cells is essential for elucidating pathogenesis and developing new therapeutics. Here, a supramolecular assembly, SCY-3, has been designed to monitor autophagy by selectively lighting-up the G-quadruplex structures entering the lysosomes. SCY-3 exhibits low cytotoxicity, long optical detection wavelength, and excellent photostability, making it ideal for prolonged tracking in single cells and living organisms. Notably, SCY-3 can rapidly penetrate lysosomes, offering significant advantages in fast staining. These attributes position SCY-3 as a promising universal tool for autophagy tracking with broad applicability.