BKN-1 is a bifunctional ligand that can not only track the formation of mtG4s (G-quadruplexes, four-stranded DNA structures containing Hoogsteen bonds) through far-red emission, but can also induce mitochondrial dysfunction. BKN-1 has anti-tumor activity and may cause mtDNA loss, damage mitochondrial integrity, reduce ATP levels, and trigger ROS imbalance, leading to apoptosis and autophagy.