Shortwave infrared absorbing and fluorescent BODIPY J-aggregates for high-contrast <i>in vivo</i> imaging

J-Aggregates hold significant promise for high-resolution shortwave infrared (SWIR) imaging, yet achieving robust SWIR absorption and emission simultaneously has been hindered by hypsochromic shifts in absorption and emission quenching caused by undesirable H- and random aggregation. To address this, we developed highly fluorescent BODIPY J-aggregates exhibiting absorption and emission spanning 1000-1600 nm. A key innovation was the implementation of a zig-zag molecular design, which effectively suppressed H-aggregation and minimized intermolecular interactions, thereby enabling anti-quenching SWIR emission. This design strategy was successfully translated into practical applications, yielding water-soluble nanoparticles capable of micron-resolution, multiplexed fluorescence, and photoacoustic <i>in vivo</i> imaging. This work establishes crucial design principles for creating highly efficient SWIR imaging agents.