J‐Aggregation‐Induced Ultra‐Long 1281 nm NIR‐II Multimodal Imaging of a Narrow‐Bandgap Squaraine for Photothermal Therapy Guidance

Multimodal phototheranostics combines multi-dimensional optical imaging with light-activated therapy, offering a promising approach for precise cancer treatment. A major hurdle is creating long-wavelength organic molecules that can concurrently support multiple second near-infrared window (NIR-II) imaging modalities and synergistic phototherapy. Herein, we report a novel donor-acceptor-donor (D-A-D) structured squaraine dye (SQ8), rationally designed and selected via preliminary DFT calculations