Architecting NIR-II metal supramolecular dyes-illuminating the path to precision medicine

Precision medicine calls for molecular tools that enable high-resolution imaging at depth, accurate lesion localisation and controllable therapy. Small-molecule dyes are widely used in biomedical imaging and treatment, yet their limited photostability, susceptibility to quenching in physiological environments and rapid in vivo clearance continue to hinder clinical translation. Coordination-driven supramolecular chemistry offers a promising route to address these shortcomings. However, progress in in vivo delivery and biodistribution, real-time visual tracking and therapeutic evaluation has often been constrained by short-wavelength excitation and emission. In this context, second near-infrared (NIR-II) metal supramolecular dyes assembled directly from NIR-II ligands have been rapidly developed, furnishing platforms with strong NIR-II performance and tunable photophysical behaviour. This perspective summarises design and construction strategies for NIR-II metal supramolecular dyes, highlights their key photophysical characteristics, and surveys representative applications in cancer, antibacterial and cardiovascular theranostics and imaging. We further discuss outstanding challenges for clinical translation and outline future opportunities for NIR-II metal supramolecular dyes in precision medicine.